Procedure to Install Pro and Pro Plus Thumbs on 319D, 320D RR L, 320D L, 320E L, 320E RR L, 324D L, 324E L, 325D L, 329D, 329E L, 336E, 336F, 349E and 349F Hydraulic Excavators {0679, 6129} Caterpillar

Excavator

311D (S/N: DDW1-UP)

319D (S/N: FMH1-UP; EAW1-UP)

320D (S/N: XCK1-UP; SPN1-UP; PHX1-UP)

320E (S/N: TNJ1-UP; WBK1-UP; TFX1-UP)

324D (S/N: PYT1-UP)

324E (S/N: PNW1-UP)

325C (S/N: BKW1-UP; BLX1-UP)

325D (S/N: AZP1-UP; A3R1-UP)

329D (S/N: JHJ1-UP)

329E (S/N: ZCD1-UP)

336E (S/N: YEP1-UP; BZY1-UP)

336F (S/N: KGH1-UP; LCL1-UP; SSN1-UP)

349E (S/N: KCN1-UP; MPZ1-UP)

349F (S/N: KEA1-UP; HLB1-UP)

Telehandler

TL1255C (S/N: DHW1-UP)

Thumb

THUMB (S/N: THC1-UP; THD1-UP; 7JW1-UP)

Work Tool

BUCKET (HYD) (S/N: ARK1-UP; 7KW1-UP)

Introduction

This Special Instruction is for installing the Pro and Pro Plus thumbs on machines. Machines which have a thumb ready stick (TRS) or standard stick machines which requires a bracket and reinforcement plate to be installed.

Reference: Operation and Maintenance Manual, SEBU9015, "Hydraulic Hex Thumbs" .

Reference: Service Guide, SEBD0512, "Caterpillar Service Welding Guide"

Reference: Special Instruction, REHS1841, "General Welding Procedures"

Welding Requirements

Welding quality is critical to the success of the installation procedures. Welds must be smooth and continuous. Do not undercut the welds. No overlap is allowed. Grind the ends of the welds to a smooth radius.

Prepare the metal for welding according to the next section. Refer to the illustrations in this special instruction for welding symbols and specifications.

Be sure that all electrodes are dried. The electrodes can be dried by heating the electrodes to 300°C (572°F). The electrodes must be dried for at least 30 minutes.

Do not weld in windy conditions. Do not weld when temperatures are below 16°C (60°F).

Penetration characteristics may vary greatly depending on the following conditions:

• Electrode diameter

• Shielding gas

• Welding current

• Plate thickness

The following items also affect the welds:

• Geometry of welded joints

• Surface conditions

• Composition of the base metal and of the electrode

For more welding information, consult the General Welding Procedures, REHS1841.

Preparing the Metal for Welding

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Personal injury can result from flame cutting or welding on painted areas. The effect of gasses from burned paint is a hazard to the person doing the cutting or welding. Do not flame cut or weld on painted areas.

All grease, paint, and foreign objects must be removed before welding. Any of these materials will discharge gas which will cause porosity in the weld deposit. Water and rust will cause hydrogen embrittlement. Hydrogen embrittlement causes cracks in the weld deposit.

Remove foreign objects with a wire brush, a buffer, or a grinder. Shot blasting the appropriate areas will also remove foreign material.

Note: After welding, allow all areas to cool to room temperature. After the areas have cooled, paint the area with primer. After the primer has dried, coat the area with Cat 4C-4200 Yellow Paint.

Safety Section

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Personal injury or death can result from sudden work tool movement. Sudden movement of the work tool can cause injury to persons near the work tool. To prevent injury or death, make sure that the area around the work tool is clear of personnel and obstructions before operating the work tool.

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Personal injury or death can result from improper lifting or blocking. When a hoist or jack is used to lift any part or component, stand clear of the area. Be sure the hoist or jack has the correct capacity to lift a component. Install blocks or stands before performance of any work under a heavy component. Approximate weights of the components are shown. Clean all surfaces where parts are to be installed.

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.

Required Parts

Installation Procedure

Prevent the machine from movement. Park the machine on a level surface.

Illustration 1	g00104545

Note: If the stick is equipped with the mounting bracket and stop plate, disregard instructions for installing mounting bracket and stop plate. Follow all other instructions to install thumb assembly.

Attach a "Do Not Operate" warning tag to the start switch or controls before you service or repair the equipment. These warning tags (Special Instruction, SEHS7332) are available from your Cat dealer.

This procedure will require the use of a suitable lifting device or devices to hold the parts safely.

Procedure to Install the Pro Plus Thumb

Illustration 2	g03030986
Typical example of a Pro Plus Thumb (A) Cylinder Mounting Bracket (8) Thumb Assembly (9) Hydraulic Cylinder (10) Idler Link As (16) Cap Plate (19) Pin

Illustration 3	g06235117
For general reference only. Some parts not shown. (1) Grease Fitting (2) Washer (3) Spacer Plate (4) Retainer (5) Link (6) Spacer (7) Pin (8) Thumb Assembly (9) Hydraulic Cylinder (10) Idler Link Assembly (11) Idler Link Assembly (12) Link (13) Pin Assembly (14) Pin Assembly (15) Stop Plate (16) Cap Plate (17) Pin (18) Shim (19) Pin (20) Washer (21) Nut (22) Locknut (23) Pin (24) Hard Washer (25) Bolt (26) Bolt (27) Bolt (28) Bolt (29) Locknut (30) Bolt (31) Hard Washer

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Illustration 4	g03084757

1. Support the thumb assembly on a flat level surface.

2. Remove the new stick pin (19) from the thumb assembly (8) and place the new stick pin and shims to the side.

3. If the machine is equipped with a pin grabber coupler, remove the bucket from the coupler.
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   Illustration 5	g03286219
   Machine with pin grabber coupler, bucket removed (8) Thumb Assembly

4. Arrange thumb assembly (8) beneath the excavator boom as shown in Illustration 5.

   Note: The excavator boom could prevent an overhead lifting device from providing adequate range of motion to arrange the thumb. The use of a sufficiently rated surface mounted lifting device such as an engine hoist or suitable lifting device.

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   Illustration 6	g03286260
   Positioning for stick nose pin removal

5. Arrange the coupler so that the coupler rests on a flat level surface. Arrange the stick directly above the coupler so the stick exerts no down pressure on the coupler as shown in Illustration 6.
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   Illustration 7	g03042136
   Stick nose pin removal

6. Remove the main stick pin from the stick and bucket, or coupler.
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   Illustration 8	g03286277
   Pin alignment

7. Align the pin bores of the thumb with the pin bores of the stick and bucket, or stick and coupler.
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   Illustration 9	g03042161
   Thumb frame centering. Top view.

8. Center the thumb frame with the stick as shown in Illustration 9.

   Note: Shim left or right to center on stick.

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   Illustration 10	g03286316
   Stick nose pin insertion (19) Pin

   Note: The maximum allowable distance between the stick centerline and the thumb centerline is 4 mm (0.2 inch). Failure to properly center the thumb frame will result in an increased rate of wear.

9. Install the stick pin retention components to secure the stick pin. See Illustration 5 for a reference.
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   Illustration 11	g03485676
   Shown with thick washer - interference fit

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   Illustration 12	g03485677
   Shown with thin washer for necessary clearance

   Note: When installing the stick pin, check the clearance between the thumbs frame and the flag pin bolt. If required, remove the thick washer and replace with the thinner washer supplied, refer to Illustration 11 and Illustration 12.

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   Illustration 13	g03286277
   Arrange the thumb for linkage installation

10. Support the thumb or lower the thumb to the same surface that the coupler (or bucket) is resting upon.

Installation of Thumb Linkage

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Illustration 14	g06241894
Non grade control machine/Grade control machine (D1) Sensor

1. Identify if machine is equipped with the grade control or not.
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   Illustration 15	g06241791

2. Remove the left side bucket link from the machine. Do not damage the sensor positioned on the back side of the factory link. Refer to Illustration 15.

   Note: Keep the right side bucket idler link installed to ensure proper alignment of the linkage.

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   Illustration 16	g06241793
   Rotary encoder link

3. Remove the sensor from the factory bucket idler link and install the sensor into the thumb idler link using factory hardware.

   Note: Skip this step if the machine is not equipped with the rotary encoder type Cat Grade Control system and sensor not present.

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   Illustration 17	g06241794
   Non grade control machine/Grade control machine

4. Install the thumb link by aligning the link bores with the two pins still assembled on the machine linkage. Secure the link at the bucket cylinder pin only.
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   Illustration 18	g06241895
   (6) Spacer

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   Illustration 19	g06241796
   (6) Spacer

5. Install spacer on bucket idler pin. This spacer is used as a shim for internal cylinder position type Cat Grade Control systems or machines without Grade Control systems. Refer to Illustration 18 and Illustration 19.
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   Illustration 20	g06241887

6. Install the left-hand side thumb link on the factory bucket idler link pin as shown in Illustration 20.
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   Illustration 21	g06241888

7. Install the thumb stick pin from the left side and push the factory pin out as shown in Illustration 21. Align the slot on the pin keeper head with the tab welded to the new bucket link.
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   Illustration 22	g06241889

8. Install right thumb link on the thumb stick idler pin. Secure the thumb link pin with the proper hardware. Refer to Illustration 22.

Installation of the Hydraulic Cylinder, Bracket Assembly, Stop Pads, and Reinforcement Plate

Note: This procedure is not required for thumb ready sticks.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

Cylinder installation is the same for standard sticks or thumb ready sticks. When installing the thumb onto a standard stick, installation of the bracket and reinforcement plate will be needed.

Note: When installing the thumb onto a heavy-duty stick, the reinforcement plate will not be needed. Do not install this item.

1. Arrange the machine so the bottom of the stick is accessible.

2. Remove paint as needed for a clean welding surface.

3. Center reinforcement plate (B) on the bottom of the stick as shown in Illustration 23.
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   Illustration 23	g02851385
   Close up of areas of the stick to be welded Follow instructions for mounting location of the Bracket As. (A) Bracket As (B) Reinforcement plate (S) Stick (Y) Distance from the end of the plate of the stick to the reinforcement plate. (Z) Distance from the sides on the stick (W1) AWS A5.18ER70S-2 or equivalent

4. Weld reinforcement plate (B) to the stick. Tack weld and finish the weld at final assembly. Refer to Table 2 for corresponding model and measurements.
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   Table 2

   Measurements for Reinforcement Plate Placement
   Model	(Y)	(Z)
   319D	211.6 mm (8.33 inch)	17.4 mm (0.685 inch)
   320D 320E 324D 324E	211.6 mm (8.33 inch)	15 mm (0.6 inch)
   325D 329D 329E 330F	220 mm (8.7 inch)
   336E and 336F	206.2 mm (8.12 inch)
   349E and 349F(1)	163.4 mm (6.43 inch)(2)	20 mm (0.8 inch)

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   (1)	With 3.9 m (12.8 ft) stick
   (2)	Add 125 mm (4.92 inch) if pin grabber is installed.

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   Illustration 24	g06235118

5. Install stop pad (15) onto the thumb using the following parts: bolt (26), washer (20), and locknut (29).

   Note: The stop pad bolt nuts need to be on the outside of the stop pad (not on the side toward the power link). The washer should be located between the stop pad and the inside of the thumb plate.

6. Stop pad bolts should not be tightened to full bolt torque, tighten the bolts until the stop pads cannot be rotated by hand.

   Note: Adjust (left to right) stop pad height after the thumb is fully installed on the stick.

7. Using a suitable lifting device rotate the thumb towards the bottom of the stick. Ensure that the stop pads will contact the reinforcement plate and contact the stick evenly.

   Note: Both stops need to contact the stick simultaneously. This contact is important to the life of the thumb and stick. In the occasion any part of the stop has more than 1 mm (0.03937 inch) of clearance, adjustments to the stops will be needed. When adjustments are needed, the technician will need to grind on the stop pad bolt hole. Level the pads left to right to ensure simultaneous contact with the stick.

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   Illustration 25	g03044085
   Cylinder installation (A) Bracket Assembly (9) Hydraulic cylinder (14) pin (17) pin

8. Using a suitable lifting device, arrange the cylinder (9) along the stick and pin the cylinder to the link assembly using pin (14). Lower the cylinder to a resting arrangement.

9. Pin the cylinder mounting bracket (A) to the cylinder using pin (17). Ensure the cylinder hydraulic tube is located on the left side of the machine.
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   Illustration 26	g03317316
   Required clearance between thumb and stick. (H) 8 mm (0.3 inch)

10. Fully curl the stick into the transport arrangement. Ensure the stop pads rest against the reinforcement plate on the bottom of the stick.

11. Loosen the four bolts that hold the cylinder port cover on each side of the cylinder. Loosening the cover will relieve any pressure or vacuum trapped in the cylinder. Verify that the cylinder is fully retracted.

12. Manually extend the cylinder 6.5 mm (0.25 inch) from being retracted.

    Note: Spacer plate (D) is required on 349E machines that have a 3.35 m (11 ft) stick, unless a pin grabber and link are installed. If a spacer plate is not necessary, skip Step 13.

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    Illustration 27	g03465822
    Bottom view for bracket placement (D) Spacer plate (T) 30 mm (1.18110 inch) minimum

13. Weld spacer plate (D) onto stick as shown in Illustration 27.
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    Illustration 28	g03042820
    Cylinder bracket fitup on stick. (E) Grind clearance on stick (F) Factory stick weld

14. Verify that the cylinder bracket assembly (A) flush to the stick. There should not be more than 2 mm (0.08 inch) between the bracket and stick. If needed, grind or machine a groove in the bracket plate to have clearance for a factory stick weld. Must grind off sharp corners. Do Not Grind Factory Stick Weld!

15. Verify that the cylinder bracket assembly (A) is centered on the stick and with the thumb linkage.

16. Mark the bracket arrangement location on the stick and prepare the stick surface for welding the bracket to the stick.

17. Place cylinder bracket back onto the stick. Verify that there is 6.5 mm (0.25 inch) of stroke left in the cylinder (from being fully retracted).

18. Tack weld the cylinder bracket to the stick.

19. Attach machine hoses to the thumb cylinder.

20. Arrange the stick as shown in Illustration 25 ( or as flat as possible).

21. Slowly open and close the thumb four times to remove the air from the system. Do not apply significant force to the thumb at this time. Ensure that the cylinder barrel or links do not contact the stick or any part of the thumb at full retract and full extend.

22. If the machine is equipped with a coupler, install the bucket. Refer to the coupler Operation and Maintenance Manual for the proper coupling procedure.

23. Arrange the bucket in the full dump arrangement by retracting the bucket cylinder.
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    Illustration 29	g03042916
    Fully extended thumb.

24. Slowly close the thumb until the cylinder is fully extended. Do not apply significant force to the thumb at this time. Ensure that the thumb teeth contact either the bucket edge or teeth.

    Note: If the teeth of the thumb interfere with the teeth of the bucket, the work tools may become lodged together and damage can occur.

25. Verify that clearance exists between the bucket hinge plate area and the thumb frame when the thumb is tight against the bucket.

26. If the thumb frame contacts the bucket hinge plate area before thumb teeth contact the bucket edge, contact "The Dealer Solution Network" for guidance.

    Note: If the thumb frame hits the bucket hinge plate area before the thumb teeth hit the bucket edge, premature bucket and thumb damage will occur.

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    Illustration 30	g03042956
    Fully retracted thumb.

27. Carefully open the thumb until the thumb cylinder is fully retracted. Ensure that the cylinder barrel does not contact the stick or any part of the thumb. Ensure that the thumb frame contacts the bottom of the stick on the reinforcement plate evenly.

28. Safely relieve all hydraulic pressure from the thumb and disconnect the hydraulic lines from the cylinder.

    Note: Refer to Operation and Maintenance Manual, "System Pressure Release".

29. Remove the thumb cylinder from the mounting bracket.

30. Using a suitable lifting device, remove the thumb cylinder from the thumb.

31. Using a suitable lifting device, raise the thumb linkage of the stick.

Final Assembly

1. Weld the bracket using an 8 mm (0.3 inch)fillet weld. Do not weld across the stick.
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   Illustration 31	g02851402
   Typical example of a stick (A) Bracket As (B) Reinforcement plate (Y) Distance from the end of the plate of the stick to the reinforcement plate. (Z) Distance from the sides on the stick

2. Weld the reinforcement plate using a 6 mm (0.24 inch)fillet weld. Do not weld across the stick.

   Note: Reinforcement plate weld must not stick up above the surface of the reinforcement plate. If the weld sticks up above the surface of the reinforcement plate, the stop pad bolts may break prematurely.

3. Allow the welded area to cool. Prepare the welded area for paint application.

4. Apply the rust prevention coat and the finish coat to the work area that has been completed. Use Caterpillar authorized paint.

5. Install the thumb cylinder following the procedures listed above.

6. Tighten all fasteners to the standard torque specifications except for the stop pad bolts.

7. Start the engine of the host machine. Cycle the hydraulic controls and check for leaks.

Procedure to Install the Pro Thumb

Illustration 32	g03055022
Typical example of a Pro Thumb (5) Thumb Assembly (7) Cap plate (10) Pin Stick (A) Hydraulic Mounting Bracket

Illustration 33	g03176790
For general reference only. Some parts not shown. (1) Grease Fitting (2) ID Plate (3) Spacer (4) Pin (5) Thumb Assembly (6) Hydraulic Cylinder Group (7) Cap Plate (8) Pin (9) Shim Plate (10) Pin (11) Setscrew (12) Nut (13) Locknut (14) Bolt (15) Bolt (16) Locknut (17) Bolt (18) Hard Washer (19) Stop Pad (20) Bolt (21) Washer (22) Locknut

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Illustration 34	g03084896

1. Support the thumb assembly on a flat level surface.

2. Remove the new stick pin (10) from the thumb assembly (5) and place the new stick pin and shims to the side.

3. If the machine is equipped with a pin grabber coupler, remove the bucket from the coupler.
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   Illustration 35	g03286380

4. Arrange thumb assembly (5) beneath the excavator boom as shown in Illustration 36.

   Note: The excavator boom could prevent an overhead lifting device from providing adequate range of motion to arrange the thumb. The use of a sufficiently rated surface mounted lifting device such as an engine hoist or suitable lifting device may also be utilized.

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   Illustration 36	g03286260
   Positioning for stick nose pin removal

5. Arrange the coupler so that the bucket rests on a flat level surface. Arrange the stick directly above the coupler so the stick exerts no down pressure on the coupler as shown in Illustration 36.
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   Illustration 37	g03042136
   Stick nose pin removal

6. Remove the main stick pin from the stick and bucket, or coupler.
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   Illustration 38	g03286396
   Pin alignment

7. Align the pin bores of the thumb with the pin bores of the stick and bucket, or stick and coupler.
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   Illustration 39	g03042161
   Thumb frame centering

8. Center the thumb frame with the stick as shown in Illustration 39.

   Note: Shim left or right to center the thumb on the stick.

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   Illustration 40	g03286419
   (19) Pin

   Note: The maximum allowable distance between the stick centerline and the thumb centerline is 4 mm (0.2 inch). Failure to properly center the thumb frame will result in an increased rate of wear.

9. Install the stick pin retention components to secure the stick pin. See Illustration 33 for reference.
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   Illustration 41	g03485676
   Shown with thick washer - interference fit

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   Illustration 42	g03485677
   Shown with thin washer for necessary clearance

   Note: When installing the stick pin, check the clearance between the thumbs frame and the flag pin bolt. If required, remove the thick washer and replace with the thinner washer supplied, refer to Illustration 41 and Illustration 42.

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   Illustration 43	g03286396

10. Support the thumb or lower the thumb to the same surface that the coupler (or bucket) is resting upon.
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    Illustration 44	g03073877
    Install new bucket linkage (G) Bucket idler link (M) Pin

11. Install new bucket idler link (G). Secure all linkage for the bucket cylinder using the proper pins (M) as shown in Illustration 44.

Installation of the Hydraulic Cylinder, Bracket Assembly, Stop Pads, and Reinforcement Plate

Note: This procedure is not required for thumb ready sticks.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

Cylinder installation is the same for standard sticks or thumb ready sticks. When installing the thumb onto a standard stick, installation of the bracket and reinforcement plate will be needed.

Note: When installing the thumb onto a heavy-duty stick, the reinforcement plate will not be needed. Do not install this item.

1. Arrange the machine so the bottom of the stick is accessible.

2. Remove paint as needed for a clean welding surface.

3. Center stop plate (B) on the bottom of the stick as shown in Illustration 45.
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   Illustration 45	g02851385
   Close up of areas of the stick to be welded Follow instructions for mounting location of the Bracket As. (A) Bracket As (B) Reinforcement plate (Y) Distance from the end of the plate of the stick to the reinforcement plate. (Z) Distance from the sides on the stick (W1) AWS A5.18ER70S-2 or equivalent

4. Weld stop plate (B) to the stick. Tack weld and finish the weld at final assembly. Refer to Table 3 for corresponding model and measurements.
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   Table 3

   Measurements for Reinforcement Plate Placement
   Model	(Y)	(Z)
   319D	211.6 mm (8.33 inch)	17.4 mm (0.685 inch)
   320D 320E 324D 324E	211.6 mm (8.33 inch)	15 mm (0.6 inch)
   325D 329D 329E 330F	220 mm (8.7 inch)
   336E and 336F	206.2 mm (8.12 inch)
   349E and 349F(1)	163.4 mm (6.43 inch)(2)	20 mm (0.8 inch)

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   (1)	With 3.9 m (12.8 ft) stick
   (2)	Add 125 mm (4.92 inch) if pin grabber is installed.

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   Illustration 46	g03465617

5. Install stop pad (19) to the thumb using the following parts: bolt (20), washer (21), and locknut (22).

   Note: The stop pad bolt nuts need to be on the outside of the stop pad (not on the side toward the power link). The washer should be located between the stop pad and the inside of the thumb plate.

6. Stop pad bolts should not be tightened to full bolt torque, tighten the bolts until the stop pads cannot be rotated by hand.

   Note: Adjust (left to right) stop pad height after the thumb is fully installed on the stick.

7. Using a suitable lifting device rotate the thumb towards the bottom of the stick. Ensure that the stop pads will contact the reinforcement plate and contact the stick evenly.

   Note: Both stops need to contact the stick simultaneously. This contact is important to the life of the thumb and stick. In the occasion any part of the stop has more than 1 mm (0.03937 inch) of clearance, adjustments to the stops will be needed. If adjustments are needed, the technician will need to grind on the stop pad bolt hole. Level the pads left to right to ensure simultaneous contact with the stick.

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   Illustration 47	g03055079
   For reference only. Cylinder installation. (A) Bracket assembly (4) Pin (6) Hydraulic cylinder (7) Cap plate (8) Pin (17) Bolt

8. Remove both thumb plate caps (7) by removing four bolts (17) on the side of the thumb frame.

9. Remove cylinder pin (4) from thumb. The cylinder pin can be tight in the thumb frame. A long punch and hammer may be used.

10. Using a suitable lifting device, arrange the cylinder (6) along the stick and pin the cylinder (6) to the thumb using pin (4). Lower the cylinder to a resting arrangement.

11. Reinstall both thumb pin caps (7) to the thumb frame.

12. Pin the cylinder mounting bracket (A) to the cylinder using pin (8). Ensure the cylinder hydraulic tube is located on the left side of the machine.
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    Illustration 48	g03317316
    Required clearance between thumb and stick. (H) 8 mm (0.3 inch)

13. Fully curl the stick into the transport arrangement. Ensure the stop pads rest against the reinforcement plate on the bottom of the stick.

14. Loosen the four bolts that hold the cylinder port cover on each side of the cylinder. Loosening the cover will relieve any pressure or vacuum trapped in the cylinder. Verify that the cylinder is fully retracted.

15. Manually extend the cylinder 6.5 mm (0.25 inch) from being retracted.

    Note: Spacer plate (D) is required on 349E machines that have a 3.35 m (11 ft) stick, unless a pin grabber and link are installed. If a spacer plate is not necessary, skip Step 16.

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    Illustration 49	g03465822
    Bottom view for bracket placement (D) Spacer plate (T) 30 mm (1.18110 inch) minimum

16. Weld spacer plate (D) onto stick as shown in Illustration 49.
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    Illustration 50	g03042820
    Cylinder bracket fitup on stick. (E) Grind clearance on stick (F) Factory stick weld

17. Verify that the cylinder bracket assembly (A) is flush to the stick. There should not be more than 2 mm (0.08 inch) between the bracket and stick. If needed, grind or machine a groove in the bracket plate to have clearance for a factory stick weld. Must grind off sharp corners. Do Not Grind Factory Stick Weld!

18. Verify that the cylinder bracket assembly (A) is centered on the stick and with the thumb linkage.

19. Mark the bracket arrangement location on the stick and prepare the stick surface for welding the bracket to the stick.

20. Place cylinder bracket back onto the stick. Verify that there is 6.5 mm (0.25 inch) of stroke left in the cylinder (from being fully retracted).

21. Tack weld the cylinder bracket to the stick.

22. Arrange the stick as shown in Illustration 47 ( or as flat as possible).

23. Attach machine hoses to the thumb cylinder.

24. Slowly open and close the thumb four times to remove the air from the system. Do not apply significant force to the thumb at this time. Ensure that the cylinder barrel or links do not contact the stick or any part of the thumb at full retract and full extend.

25. If the machine is equipped with a coupler, install the bucket. Refer to the coupler Operation and Maintenance Manual for the proper coupling procedure.

26. Arrange the bucket in the full dump arrangement by retracting the bucket cylinder.
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    Illustration 51	g03116022
    Extended thumb

27. Slowly close the thumb until the cylinder is fully extended. Do not apply significant force to the thumb at this time. Ensure that the thumb teeth contact either the bucket edge or teeth.

    Note: If the teeth of the thumb interfere with the teeth of the bucket, the work tools may become lodged together and damage can occur.

28. Verify that clearance exists between the bucket hinge plate area and the thumb frame when the thumb is tight against the bucket.

29. If the thumb frame contacts the bucket hinge plate area before thumb teeth contact the bucket edge, contact "The Dealer Solution Network"for guidance.

    Note: If the thumb frame hits the bucket hinge plate area before the thumb teeth hit the bucket edge, premature bucket and thumb damage will occur.

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    Illustration 52	g03116218
    Fully retracted thumb.

30. Carefully open the thumb until the thumb cylinder is fully retracted. Ensure that the cylinder barrel does not contact the stick or any part of the thumb. Ensure that the thumb frame stops contacts the bottom of the stick on the reinforcement plate evenly.

31. Safely relieve all hydraulic pressure from the thumb and disconnect the hydraulic lines from the cylinder.

    Note: Refer to Operation and Maintenance Manual, "System Pressure Release".

32. Remove the thumb cylinder from the mounting bracket.

33. Using a suitable lifting device, remove the thumb cylinder from the thumb.

34. Using a suitable lifting device, raise the thumb linkage of the stick.

Final Assembly

1. Weld the bracket using an 8 mm (0.3 inch)fillet weld. Do not weld across the stick.
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   Illustration 53	g02851402
   Typical example of a stick (A) Bracket As (B) Reinforcement plate (Y) Distance from the end of the plate of the stick to the reinforcement plate. (Z) Distance from the sides on the stick

2. Weld the reinforcement plate using a 6 mm (0.24 inch)fillet weld. Do not weld across the stick.

   Note: Reinforcement plate weld must not stick up above the surface of the reinforcement plate. If the weld sticks up above the surface of the reinforcement plate, the stop pad bolts may break prematurely.

3. Allow the welded area to cool. Prepare the welded area for paint application.

4. Apply the rust prevention coat and the finish coat to the work area that has been completed. Use Caterpillar authorized paint.

5. Install the thumb cylinder following the procedures listed above.

6. Tighten all fasteners to the standard torque specifications except for the stop pad bolts.

7. Start the engine of the host machine. Cycle the hydraulic controls and check for leaks.

Procedure for Welding a Plate to Each Side of the Stick

Note: Block Locations. The following information is for general reference and hard lines should be dry fit to locate blocks. Refer to Illustrations 54 and 55.

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Illustration 54	g02851377
Left side (C) Plate

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Illustration 55	g02851379
Right side (C) Plate

1. Remove paint as necessary for a clean welding surface.
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   Illustration 56	g02851383
   Close up of area for plate (C) ( C) Plate (R) 4 welds 30 mm (1.18 inch) minimum (W1) IE0012A or equivalent

2. Weld plate (C) centered on stick as shown in Illustrations 54 and 55.
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   Table 4

   319D Machine
   Stick Length (Meters)	J	K	L	M	N	P
   3.2 m (10.5 ft)	1958.6 mm (77.1 inch)	1907.6 mm (75.1 inch)	244.2 mm (9.6 inch)	1858 mm (73.1 inch)	1807 mm (71.1 inch)	243.1 mm (9.6 inch)

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   Table 5

   320D Machine
   Stick Length	J	K	L	M	N	P
   2.9 m (9.5 ft) HD Horizontal Flange	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	273.9 mm (10.8 inch)	1794.8 mm (70.7 inch)	1744 mm (68.7 inch)	280 mm (11 inch)
   2.9 m (9.5 ft) HD Vertical Flange	1795.26 mm (70.7 inch)	1744.8 mm (68.7 inch)	242.3 mm (9.5 inch)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	248.4 mm (9.8 inch)
   2.9 m (9.5 ft) Horizontal Flange	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	274.4 mm (10.8)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	280.4 mm (11 inch)
   2.9 m (9.5 ft) Vertical Flange	1796.4 mm (70.7 inch)	1745.6 mm (68.7 inch)	242.8 mm (9.5 inch)	1794.8 mm (70.7 inch)	1744 mm (68.7 inch)	248.8 mm (9.8 inch)
   3.9 m (12.8 ft) Horizontal Flange	2593.6 mm (102.1 inch)	2542.8 mm (100.1 inch)	494.4 mm (19.5 inch)	2595.6 mm (102.2 inch)	2544.8 mm (100.2 inch)	500.5 mm (19.7 inch)
   3.9 m (12.8 ft) Vertical Flange	2593.6 mm (102.1 inch)	2542.8 mm (100.1 inch)	462.8 mm (18.2 inch)	2595.6 mm (102.2 inch)	2544.8 mm (100.2 inch)	468.9 mm (18.5 inch)

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   Table 6

   320E Machine
   Stick Length	J	K	L	M	N	P
   2.9 m (9.5 ft)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	274.4 mm (10.8 inch)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	280.5 mm (11 inch)
   2.9 m (9.5 ft) HD	1795.2 mm (70.7 inch)	1744.4 mm (68.7 inch)	273.9 mm (10.8 inch)	1796 mm (70.7 inch)	1745.2 mm (68.7 inch)	280 mm (11 inch)

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   Table 7

   324D Machine
   Stick Length	J	K	L	M	N	P
   2.95 m (9.5 ft) Horizontal Flange	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	273.9 mm (10.8 inch)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	280 mm (11 inch)
   2.95 m (9.5 ft) Vertical Flange	1794.8 mm (70.7 inch)	1744 mm (68.7 inch)	242.3 mm (9.5 inch)	1796.4 mm (70.7 inch)	1745.6 mm (68.7 inch)	248.4 mm (9.8 inch)

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   Table 8

   324E Machine
   Stick Length	J	K	L	M	N	P
   2.95 m (9.5 ft)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	274.4 mm (10.8 inch)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	280.4 mm (11 inch)
   2.95 m (9.5 ft) HD	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	273.9 mm (10.8 inch)	1795.6 mm (70.7 inch)	1744.8 mm (68.7 inch)	280 mm (11 inch)

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   Table 9

   325D/329D Machine
   Stick Length	J	K	L	M	N	P
   3.75 m (12.3 ft)	2207.5 mm (86.9 inch)	2157.5 mm (84.9 inch)	272.6 mm (10.8 inch)	2206.7 mm (86.9 inch)	2156.7 mm (84.9 inch)	279.8 mm (11 inch)

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   Table 10

   325D/329D/329E/330F Machine
   Stick Length	J	K	L	M	N	P
   3.2 m (10.5 ft)	1796.7 mm (70.7 inch)	1746.7 mm (68.8 inch)	273.9 mm (10.8 inch)	1797.5 mm (70.8 inch)	1747.5 mm (68.8 inch)	280 mm (11 inch)
   3.75 m (12.3 ft)	2207.5 mm (86.9 inch)	2157.5 mm (84.9 inch)	272.6 mm (10.7 inch)	2206.7 mm (86.9 inch)	2156.7 mm (84.9 inch)	279.8 (11 inch)

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   Table 11

   336D Machine
   Stick Length	J	K	L	M	N	P
   3.2 m (10.5 ft) Horizontal Flange	1794.4 mm (70.6 inch)	1743.4 mm (68.6 inch)	282.3 mm (11.1 inch)	1795.2 mm (70.7 inch)	1744.2 mm (68.7 inch)	282.6 mm (11.13 inch)
   3.2 m (10.5 ft) Vertical Flange	1794.4 mm (70.6 inch)	1743.4 mm (68.6 inch)	250.5 mm (9.9 inch)	1794.4 mm (70.6 inch)	1743.4 mm (68.6 inch)	250.5 mm (9.9 inch)
   3.9 m (12.8 ft) Horizontal Flange	2204.4 mm (86.8 inch)	2153.4 mm (84.8 inch)	284.4 mm (11.2 inch)	2205.2 mm (86.8 inch)	2154.2 mm (84.8 inch)	284.4 mm (11.2 inch)
   3.9 m (12.8 ft) Vertical Flange	2204.3 mm (86.8 inch)	2153.3 mm (84.8 inch)	252.7 mm (9.9 inch)	2204.3 mm (86.8 inch)	2153.3 mm (84.8 inch)	252.7 mm (9.9 inch)

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   Table 12

   336E and 336FMachine
   Stick Length	J	K	L	M	N	P
   3.2 m (10.5 ft)	1801.8 mm (70.9 inch)	1750.8 mm (68.9 inch)	271.8 mm (10.7 inch)	1801.8 mm (70.9 inch)	1750.8 mm (68.9 inch)	271.8 mm (10.7 inch)
   3.9 m (12.8 ft)	2211.8 mm (87.1 inch)	2160.8 mm (85.1 inch)	271.8 mm (10.7 inch)	2211.8 mm (87.1 inch)	2160.8 mm (85.1 inch)	271.8 mm (10.7 inch)

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   Table 13

   345D Machine
   Stick Length	J	K	L	M	N	P
   3.35 m (11 ft) Horizontal Flange	2043.7 mm (80.5 inch)	1992.9 mm (78.5 inch)	285.2 mm (11.2 inch)	2050.7 mm (80.7 inch)	1999.9 mm (78.7 inch)	305.4 mm (12 inch)
   3.35 m (11 ft) Vertical Flange	2047.7 mm (80.6 inch)	1996.7 mm (78.6 inch)	254.1 mm (10 inch)	2050.2 mm (80.7 inch)	2000.2 mm (78.7 inch)	270.1 mm (10.6 inch)
   4.3 m (14.1 ft) Horizontal Flange	2564.1 mm (100.9 inch)	2513.3 mm (98.9 inch)	284.4 mm (11.2 inch)	2570.5 mm (101.2 inch)	2519.7 mm (99.2 inch)	304.2 mm (12 inch)
   4.3 m (14.1 ft) Vertical Flange	2567.3 mm (101.1 inch)	2516.5 mm (99.1 inch)	253 mm (10 inch)	2570.7 mm (101.2 inch)	2519.9 mm (99.2 inch)	268.9 mm (10.6 inch)

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   Table 14

   349D Machine
   Stick Length	J	K	L	M	N	P
   3.9 m (12.8 ft) Horizontal Flange	2562.8 mm (100.9 inch)	2512.8 mm (98.9 inch)	285.4 mm (11.2 inch)	2565.5 mm (101 inch)	2515.5 mm (99 inch)	305 mm (12 inch)
   3.9 m (12.8 ft) Vertical Flange	2563.3 mm (100.9 inch)	2512.3 mm (98.9 inch)	253.8 mm (10 inch)	2566.8 mm (101.1 inch)	2515.8 mm (99 inch)	269.7 mm (10.6 inch)

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   Table 15

   349E and 349F Machine
   Stick Length	J	K	L	M	N	P
   3.35 m (11 ft)	2050.7 mm (80.7 inch)	2000.7 mm (78.8 inch)	273.4 mm (10.8 inch)	2050.7 mm (80.7 inch)	2000.7 mm (78.8 inch)	273.4 mm (10.8 inch)
   3.9 m (12.8 ft)	2570 mm (101.2 inch)	2520 mm (99.2 inch)	272 mm (10.7 inch)	2566.3 mm (101 inch)	2516.3 mm (99.1 inch)	273 mm (10.7 inch)

3. Make a continuous extension of the root pass and fillet weld to a length of 30 mm (1.18 inch) (R) tapering to a 3 mm (0.19 inch) in height in that distance. Grind surfaces to flush at each end.

4. Allow the welded areas to cool.

5. Prepare the welded areas for paint.

6. Apply a rust prevention coat and a finish coat.

Circuit Installation

Required Hydraulic Circuit Installation

The hydraulic excavator must be equipped with an auxiliary hydraulic circuit. This circuit will connect the thumb to the attachment spool of the main valve on the hydraulic excavator. This connection will allow hydraulic pressure to flow to and from the thumb. This circuit must be a one pump, two direction flow circuits.

Setting Flows and Pressures

1. Refer to the host machine maintenance manual for the proper procedure to adjust the flow and pressure on the machine.

2. Release all air from the hydraulic system.

3. Test and adjust the maximum flows and pressures of the auxiliary hydraulic system as needed. Refer to Table 16 below for the maximum allowable pressures and flows for the thumb circuit.
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   Table 16

   Maximum Flow and Pressure Settings
   Machine	Maximum Extended Cylinder Pressure	Maximum Flow	Maximum Retracted Cylinder Pressure
   319D and 320D	20500 kPa (3000 psi)	214 L/min (56.5 US gpm)	20500 kPa (3000 psi)
   324D	20500 kPa (3000 psi)	231 L/min (61 US gpm)	20500 kPa (3000 psi)
   325D	20500 kPa (3000 psi)	247 L/min (65.5 US gpm)	20500 kPa (3000 psi)
   329D	20500 kPa (3000 psi)	247 L/min (65.5 US gpm)	20500 kPa (3000 psi)
   320E	20500 kPa (3000 psi)	214 L/min (56.5 US gpm)	20500 kPa (3000 psi)
   324E	20500 kPa (3000 psi)	231 L/min (61 US gpm)	20500 kPa (3000 psi)
   329E	20500 kPa (3000 psi)	247 L/min (65.5 US gpm)	20500 kPa (3000 psi)
   330D	20500 kPa (3000 psi)	280 L/min (74 US gpm)	20500 kPa (3000 psi)
   336D	20500 kPa (3000 psi)	280 L/min (74 US gpm)	20500 kPa (3000 psi)
   336E and 336F	20500 kPa (3000 psi)	280 L/min (74 US gpm)	20500 kPa (3000 psi)
   345D	20500 kPa (3000 psi)	386 L/min (102 US gpm)	20500 kPa (3000 psi)
   349E and 349F	20500 kPa (3000 psi)	386 L/min (102 US gpm)	20500 kPa (3000 psi)

Air Evacuation Procedure

Note: Without proper air evacuation, cylinder dieseling occurs which has lead or may lead to the deterioration of seals.

All cycling of hydraulic cylinders is to be done at engine idle speed. All cylinders shall be cycled while the rod is unpinned and properly supported. The unpinned rod will allow for unrestricted rod travel until all air is fully purged from the cylinders. Never move the rod forward or backward rapidly during the first ten complete cycles.

Note: Do not allow the rod to snub during the first two extend and retract cycles. When the rod is in the full extended position, extreme pressures are achieved in the cylinder. These extreme pressures cause a great degree of vulnerability to dieseling.

1. The process starts with the cylinder fully retracted on the vehicle. The rods shall be extended to 1/2 to 3/4 of the full stroke. A minimum of a 4 second pause must be executed before beginning to change rod direction.

2. Repeat Step 1 for the first two consecutive cycles.

3. For the next eight cycles, the rods shall be extended to full stroke. Wait a minimum of 4 seconds, pause then fully retract the rod.

4. Once in the retracted state, wait another 4 seconds before changing the rods direction of movement.

   Note: Do not allow the relief valve to open during the first 10-cycles. Care must be taken throughout the entire 10-cycle process.

Every cylinder must be subjected to this same procedure to eliminate dieseling. Upon completion of this procedure, no further special handling is required.