Usage:
7221 (98X),
7231 (17W),
7241 (39E),
7251 (74E),
7261 (89B),
7271 (36W),
D399 (91B),
D398 (67B),
D379 (69B),
D353 (47B),
D349 (62P),
D348 (38J),
3208 (75V),
3304 (5B),
3306 (67D),
3406 (91U),
3408 (99U),
3412 (60M)
IMPORTANT: Before alignment is started, the following conditions must be met:
- a) The companion flange must be installed on the propeller shaft and checked for concentricity, see page 2.
- b) The ship must be in the water with all permanent ballast in place.
- c) The fuel, water and temporary ballast tanks must be filled to normal operating levels.
- d) All major machinery over 1000 lb (450 kg) must be installed or simulated by equivalent weights appropriately located.
- e) The propeller shaft must be centered, blocked, and accurately located with respect to its final fore and aft position.
- b) The ship must be in the water with all permanent ballast in place.
General Information
(A) Face And Bore Alignment
(1) The terms bore alignment (A) and face alignment (B) are used throughout this instruction. Parallel alignment and bore alignment are synonymous, as are angular alignment and face alignment.
(2) Parallel or bore misalignment occurs when the centerlines of the driven equipment and the driving equipment are parallel but not on the same line as shown above.
(3) Angular or face misalignment occurs when the centerlines of the driven equipment and the driving equipment are not parallel as shown above.
(4) Face runout refers to the distance the face of the hub is out of perpendicular to the shaft centerline as shown above. Flange face runout must be no more than .005" (0.13).
(5) Bore runout refers to the distance the centerline of the bore of the hub is out of concentricity with the centerline of the shaft as shown above. Pilot bore runout must not exceed .005" (0.13).
(B) Indicator Readings
(1) Since all dial indicators do not indicate plus (+) in the same direction, it is necessary that a standard be established for the purpose of clarity in this instruction. In this instruction a plus (+) reading means that the tip of the indicator moved into the dial indicator; a minus (-) reading means that the tip of the indicator moved out of the dial indicator. Before taking any indicator readings, check the dial indicators being used to determine which is the plus (+) direction. If the plus (+) direction is different than the standard used in this instruction, keep this in mind when taking dial indicator readings.
(2) When comparing two plus (+) indicator readings, the larger numerical reading is more than the smaller numerical reading. However, when comparing two minus (-) indicator readings, the larger numerical reading is less than the smaller numerical reading. In both cases, the indicator reading becomes less as the tip of the indicator moves out of the dial indicator.
(3) The Total Indicator Reading (TIR) is the total amount of movement of the indicator needle. The TIR is always a positive value even though one or both of the readings are negative. For example: If the indicator reading varied from -10 to +5, the TIR was 15. If the indicator reading varied from -5 to -15, the TIR was 10.
(4) Indicator readings are taken at four locations designated A, B, C and D as shown. The dial indicator is always "zeroed" at location A before taking any readings. When taking readings, the indicator must be returned to location A to make sure the reading returns to zero. A quick way to check the validity of the readings is to remember that the reading of B + D should equal the reading at C. This is valid only when the driving and driven shafts are rotated together while checking alignment.
(C) Drivelines
(1) Gear output flange (1) is fitted to the marine transmission output shaft. Companion flange (2) is fitted to the intermediate shaft or propeller shaft (solid tailshaft) and mates with output flange (1).
(2) A solid tailshaft (3) or propeller shaft is a single shaft which may or may not use a pillow block or split bearing (4) to support the shaft.
(3) A tailshaft with an intermediate shaft (5) is a shaft which contains two or more sections. An intermediate shaft (5) is normally supported by a pillow block or split bearing (4).
(D) Close-Coupled Marine Transmissions
(1) Close-coupled marine transmissions are fastened to the engine flywheel housing and are driven directly from the flywheel. The marine transmission and engine may be fastened to common mounting rails as shown above on the left or the unit may be supported at the front of the engine and at the marine transmission as shown above on the right.
(2) When aligning close-coupled marine transmissions mounted on common rails with the engine, do not disturb bolts (1) and the shims used to fasten the marine transmission and engine to the mounting rails.
(3) To align the marine transmission and engine as a unit to the vessel's driveline, use the vertical adjustment screws (2) provided in the mounting rails or supports. The horizontal adjustment screws are not provided with the marine transmission and engine; these screws must be fastened to the ship's engine bed after the marine transmission and engine are located in their approximate final position.
(4) Marine transmissions and engines mounted on common rails must be fastened to the ship's engine bed with a minimum of one fitted bolt on each side at locations (A). Fitted bolts are optional at locations (D). Use clearance-type bolts to fasten the mounting rails to the engine bed at all other locations forward of the marine transmission.
(5) Marine transmissions and engines with separate supports use fitted bolts at the rear supports, locations (B). Fitted bolts are optional at the front supports, locations (C).
(E) Remote Mounted Marine Transmissions
(1) Remote mounted marine transmissions are driven from the engine flywheel through a flexible coupling. When installing remote mounted marine transmissions, always align the transmission to the vessel's driveline, then the engine to the transmission.
IMPORTANT: If the cylinder block must be replaced, always check the alignment with the remote mounted transmission after installation of the replacement cylinder block.
(2) Use vertical adjustment screws (1) to align the marine transmission to the driveline. Vertical adjustment screws (2) on the engine mounting rails are used to align the engine to the marine transmission. The horizontal adjustment screws (3) are not provided with the marine transmission and engine; these screws must be fastened to the ship's engine bed after the transmission and engine are located in their approximate final position.
NOTE: On earlier 7271 Marine Transmissions (serial numbers 36W1 - 36W221), 5N6722 Plate (4) (left) and 5N6721 Plate (5) (right) must be installed on the transmission before installation and alignment. These plates must be used to get enough clearance to drill the holes through the ship's engine bed for mounting of the transmission. Before installation of plates (4) and (5), tack weld each of the bolts (locations A) to the plates in three places.
(3) Before taking indicator readings during the alignment of the engine to the remote mounted transmission, always move the engine crankshaft to the end of its end play toward the front of the engine, and the coupling shaft to the end of its end play toward the engine. Do not use force against the crankshaft or coupling shaft while taking the indicator readings. After installation and alignment of the engine, the crankshaft end play must not be less than before installation of the engine.
(4) After alignment, fasten the marine transmission to the engine bed with fitted bolts at locations (D). Fitted bolts are optional at locations (E). Fasten the engine's mounting rails to the engine bed with fitted bolts or dowels in the rear corners, locations (B). Use clearance type bolts at all other locations (C).
(F) Mounting Marine Transmissions And Engines With Steel Shims
After the engine and/or transmission has been aligned, steel shims can be made to fit between the mounting pads of the engine rails and the engine bed or between the supports of the remote mounted transmission and the engine bed. Use mild steel plates that are 10 to 12 sq.in. (6450 to 7740 sq.mm) in area. These plates must be machined to specific thicknesses for each pad or mounting location. Identification must be put on the shims and their matching location on the engine bed. The machining of these shims must provide a uniform zero clearance fit under each pad or support. Alignment must be maintained between the engine and transmission or between the transmission and propeller shaft when the shims are inserted in their respective positions and the anchor bolts are tightened.
IMPORTANT: When steel shims are used between the mounting pads or supports and the engine bed, the mounting surfaces must be flat, free of burrs and parallel to the bottom surface of the mounting pads or supports.
Engines and Transmissions With Mounting Brackets
(1) Use steel shims as necessary between the ship's engine bed and the mounting brackets to get the engine and transmission in correct alignment with the propeller shaft. Make sure the engine and transmission mounting brackets are in equal contact with the shims at all locations. If the brackets are not in solid contact with the shims before the anchor bolts are installed, the engine and/or transmission can be stressed when the anchor bolts are tightened.
(2) Do not weld the mounting brackets to the engine bed as this will cause distortion of the brackets. There are sufficient bolt holes in the transmission mounting brackets to restrain propeller thrust. However, to ensure that alignment remains intact, fitted bolts can be used to fasten the transmission mounting brackets to the engine bed. Use clearance type bolts to fasten the engine mounting brackets in place.
Engines And Transmissions With Mounting Rails
After the transmission and engine have been aligned with the propeller shaft, shims made from mild steel must be machined to provide a uniform zero clearance fit between the engine bed and all mounting pads of the rails.
(1) The shims must be installed only at the mounting pad locations of the mounting rail. The shim area must not exceed 12 sq. in. (7740 sq. mm) per bolt hole or extend inboard of the mounting pad.
(2) On close coupled transmissions, a minimum of one fitted bolt must be used at the rear of each rail. Fitted bolts at other locations in the rail rearward of the flywheel housing are optional. Use clearance type bolts at all other locations. Never use fitted bolts forward of the transmission.
(3) For engines with a remote mounted transmission, use a fitted bolt on each side of the engine at the rear of the mounting rails. Use clearance type bolts at all other locations. Do not use fitted bolts forward of the flywheel housing.
(4) For remote mounted transmissions, use a minimum of one fitted bolt on each side at the rear of the transmission. Fitted bolts are optional at the other mounting hole locations.
(5) All bolts, except the fitted bolts, must be .06" (1.5) less in diameter than the diameter of the holes in the mounting rails.
(6) Tighten all mounting bolts to a torque of 360 lb.ft. (490 N·m). Use two nuts on each mounting bolt.
(G) Mounting Marine Transmissions And Engines With Poured Resin Shims
After the engine and transmission have been aligned to the propeller shaft or the engine has been aligned with the remote mounted transmission, poured resin shim material can be used between the engine rails and the engine bed. When using poured resin shim material, always follow the manufacturer's installation recommendations and the following guidelines.
(1) Use foam rubber strips of the appropriate thickness to form the dams for pouring the shim material.
(2) Do not pour shim material inboard of the machined pad on the bottom of the mounting rail.
(3) The shim material can be poured the full length of the mounting rail (a continuous pour) or it can be poured only at the mounting pad locations (an interrupted pour). If an interrupted pour is used, the minimum area of shim material must be 45 sq.in. (29,000 sq.mm) per mounting bolt. If the mounting rails have mounting pads only at the bolt hole locations, foam rubber strips must be installed on both sides of each pad on all pads forward of the flywheel housing to provide for expansion. These expansion strips permit thermal expansion of the mounting rails at operating temperature. On engines whose mounting rails have full length mounting pads, no expansion strips are necessary.
NOTE: When realigning an existing installation, installation of the full length foam rubber strips for a continuous pour can often be difficult because of limited access. Therefore, it is recommended that a full length continuous pour be used only for new installations where the engine can be raised to install the foam rubber strips. Use an interrupted pour for all other applications.
IMPORTANT: When poured shim material is used, do not use mounting bolts in all of the bolt holes in the mounting rails. On close coupled transmissions, use three out of the four available bolt holes (two rear and one front on each side) at the transmission portion of the mounting rails. The engine portion of the mounting rails uses only six bolts (two at the rear by the flywheel housing and one at the front on each side). Use a fitted bolt at the rear of each rail, locations (A). Fitted bolts at locations (B) are optional. Do not use bolts at locations (C). Use clearance type bolts at all other locations.
(4) Do not pour the shim material thicker or thinner than the manufacturer's recommendation. If the clearance between the bottom of the mounting pad and the top of the engine bed is more than the maximum allowable thickness of the shim material, use steel spacers. The spacers must be a minimum of 45 sq.in. (29,000 sq.mm) in area per mounting bolt.
(5) Before pouring the shim material, install all mounting bolts finger tight. Put sealing material around each bolt at the bottom of the mounting pad to prevent the shim material from filling the bolt holes in the mounting rails. If shim material is allowed to enter the bolt holes in the rails, this will prevent thermal expansion of the rails.
(6) After the shim material has sufficiently hardened according to the manufacturer's specification, the mounting bolts should be tightened to a torque of 360 lb.ft. (490 N·m). Use two nuts on each mounting bolt.
Transmissions
After the remote mounted transmission has been aligned with the propeller shaft, poured resin shim material can be used between the engine bed and the transmission supports. When using poured resin shim material, always follow the manufacturer's installation recommendations and the following guidelines.
(1) The shim material should be poured the full length and width of the transmission support surface.
(2) Use foam rubber strips of the appropriate thickness to form the dams for pouring the shim material.
(3) Before pouring the shim material, install all of the mounting bolts finger tight. Put sealing material around each bolt at the engine bed and support.
(4) Use a minimum of one fitted bolt on each side at the rear of the transmission. Fitted bolts are optional at the other mounting hole locations.
(5) After the shim material has sufficiently hardened according to the manufacturer's specifications, the mounting bolts should be tightened to a torque of 360 lb.ft. (490 N·m). Use two nuts on each mounting bolt.
(H) Tools Needed
- (1) 6V2042 Alignment Yoke.
- (2) 6V2043 Alignment Bar.
- (3) 1/2" Diameter × 12" long threaded rod with nuts.
- (4) Adapters to mount dial indicators on alignment yoke (fabricate to fit dial indicators used).
- (5) Starrett Dial Indicator Set No. 196 or Caterpillar 8S2328 Dial Indicator Group or equivalent. (Two dial indicators are required).
- (6) Caterpillar 6F6922 Depth Micrometer or equivalent.
- (7) Starrett Dial Gauge No. 696 and Balancer Attachment 696B (Use to check crankshaft deflection).
- (8) Thickness gauge.
- (2) 6V2043 Alignment Bar.
Alignment Of Marine Transmission In Vessels With Solid Tailshaft
On vessels using a solid tailshaft with a bearing located between the transmission and the stuffing box, the drive train should already be aligned from the stern bearing to the split bearing. This instruction covers alignment from the split bearing, or the first bearing aft of the transmission to the transmission. For remote mounted marine transmissions, use the following procedure to align and install the marine transmission only. After the transmission has been aligned and permanently fastened in position, use the procedure shown on page 23 to align the engine to the transmission.
(1) Position the engine and/or marine transmission on the vessle's engine bed, as close to the final aligned position as possible. Move the tailshaft toward the rear of the vessel so there is approximately .30" (7.6) clearance between the gear output flange (1) and companion flange (2). Use a fabricated split collar (3) at the stuffing box or split bearing to retain the shaft in this position.
(2) Mount the dial indicators rigidly, independent of the shaft with the tips of the indicators at positions (X) and (Y), on the top of the shaft close to the stuffing box or bearing and on the top of the companion flange. Zero the indicators.
(3) Use a jack or hoist to raise the flange end of the shaft until .001" (0.25) is indicated at (X). With the shaft in this position, record the indicator reading at (Y). Divide the reading at (Y) by two and lower the shaft to this position. This is the shaft's true position. The shaft must remain in this position throughout all alignment procedures.
(4) Move the marine transmission output shaft to the rear of its end play and check to be sure split collar (3) is against the stuffing box or split bearing. Install 6V2042 Alignment Yoke (4), 6V2043 Alignment Bar (5) and the dial indicator on the transmission output flange with the tip of the indicator on the face of the companion flange as shown to check face alignment. Zero the indicator at position (A).
(5) Rotate the transmission output shaft and record the indicator reading when the indicator is at positions (B), (C), (D) and again at (A). If a TIR of more than .005" (0.13) is obtained between (B) and (D), use horizontal adjustment screws (6) at the rear of the transmission and engine (or transmission if remote mounted) until a TIR of .005" (0.13) or less is obtained.
(6) If a TIR of more than .005" (0.13) is obtained between (A) and (C), adjust vertical adjustment screws (7) at the rear of the transmission and engine (or transmission if remote mounted) until a TIR of .005" (0.13) or less is obtained.
(7) To check bore alignment, put the tip of the dial indicator on the top of the companion flange at position (A) as shown. Zero the indicator. Rotate the transmission output shaft and record the indicator reading when the indicator is at positions (B), (C), (D) and again at (A).
(8) If a TIR of more than .005" (0.13) is obtained between (B) and (D), use horizontal adjustment screws (6) and (8) until a TIR of .005" (0.13) or less is obtained. Make sure each screw is turned the same amount in order to retain face alignment.
(9) If a TIR of more than .005" (0.13) is obtained between (A) and (C), adjust vertical adjustment screws (7) and (9) until a TIR of .005" (0.13) or less is obtained. Make sure each screw is turned the same amount in order to retain face alignment.
(10) Move the tailshaft forward until the output flange pilot starts to engage with the pilot bore in the companion flange. Check the face and bore alignment again, and make adjustments as necessary.
(11) Drill the mounting holes through the engine bed using the holes in the mounting rails or supports as a guide. See the General Information section of this instruction to determine which mounting holes must use fitted bolts and which must use clearance type bolts. Holes for fitted bolts must be interference fit; holes for clearance type bolts must be .06" (1.5) less than the diameter of the holes in the engine mounting rails or supports.
(12) On engines with mounting feet, use steel shims between the mounting feet and the engine bed.
(13) On engines with mounting rails, either steel shims or poured resin shims can be used between the rails and the engine bed.
(14) If steel shims are to be used between the engine rails or supports and the engine bed, see MOUNTING MARINE TRANSMISSIONS AND ENGINES WITH STEEL SHIMS on page 6.
(15) If poured resin shims are to be used between the engine rails and the engine bed, see MOUNTING MARINE TRANSMISSIONS AND ENGINES WITH POURED RESIN SHIMS on page 8.
(16) After the shims have been installed and the mounting nuts tightened, again check the face and bore alignment to be sure that it is correct.
(17) If there are alignment marks on the outside diameter of the companion flange and output flange, rotate the output flange until these marks are in alignment. Move the tailshaft forward until the flange faces are in full contact. Install the flange bolts and tighten them to their specified torque.
(18) After alignment has been completed and all anchor bolts have been tightened to their final torque, the engine crankshaft deflection check, shown on page 31, must be performed on all engines (except D346 and D379 engines) with mounting rails and engine side covers.
Alignment Of Marine Transmission In Vessels With Intermediate Shaft
NOTE: For remote mounted marine transmissions, use the following procedure to align and install the transmission only. After the transmission has been aligned and permanently fastened in position, use the procedure shown on page 23 to align the engine to the marine transmission.
(1) Fabricate two fixtures (1) and tack weld a fixture to the vessel structure at each end of the intermediate shaft. Do not install the split bearing or pillow block at this time.
(2) With the tailshaft in its installed position, locate the intermediate shaft so there is approximately .50" (12.7) gap between the tailshaft flange and the intermediate shaft flange. Use a split collar (2) at the stuffing box to locate the tailshaft.
(3) Mount the dial indicators independently of the shaft with the tips of the indicators at positions (X) and (Y), on the top of the shaft close to the stuffing box or bearing and on the top of the tailshaft flange. Zero the indicators.
(4) Use a jack or hoist to raise the flange end of the tailshaft until .001" (0.25) is indicated at (X). With the shaft in this position, record the indicator reading at (Y). Divide the reading at (Y) by two and lower the shaft to this position. This is the tailshaft's true position. The tailshaft must remain in this position throughout all alignment procedures.
(5) Mark the flange of the tailshaft and the intermediate shaft at positions (A), (B), (C) and (D), 90° apart with position (A) located at the top.
(6) Use a depth gauge or thickness gauge to measure the gap between the two flanges at positions (B) and (D). The difference between the two readings must not exceed .005" (0.13). Adjust alignment bolts (3) and (4) until the gap difference is .005" (0.13) or less.
(7) Measure the gap between the two flanges at positions (A) and (C). The difference between the two measurements must not exceed .005" (0.13). Adjust the rear alignment bolts (5) until a gap difference of .005" (0.13) or less is obtained.
(8) Install 6V2042 Alignment Yoke (6), 6V2043 Alignment Bar (7) and the dial indicator on the intermediate shaft with the tip of the indicator on the bore of the tailshaft flange as shown. Zero the dial indicator at position (A). Rotate the intermediate shaft and record the indicator reading when the tip of the indicator is at positions (B), (C), (D) and again at (A).
(9) If a TIR of more than .005" (0.13) is obtained between (B) and (D), loosen alignment bolts (3) and (8) while tightening bolts (4) and (9) the same amount; or tighten alignment bolts (3) and (8) while loosening bolts (4) and (9) the same amount. Adjust the alignment bolts until a TIR of .005" (0.13) or less is obtained between (B) and (D). Make sure each bolt is turned the same amount in order to retain face alignment.
(10) If a TIR of more than .005" (0.13) is obtained between (A) and (C), loosen bolts (5) and (10) the same number of turns or tighten bolts (5) and (10) the same number of turns until a TIR of .005" (0.13) or less is obtained between (A) and (C). Make sure all bolts are loosened or tightened the same amount in order to retain face alignment.
(11) Install the pillow block or split bearing. Determine and install the proper thickness of shims under the pillow block or bearing. Remove the alignment yoke, bar and dial indicator. Move the intermediate shaft to the rear until the flange faces are in full contact. Install the flange bolts and tighten them to their specified torque.
(12) Position the engine and/or marine transmission as close to their final aligned position as possible. Move the intermediate shaft and tailshaft toward the rear of the vessel until there is approximately .30" (7.6) clearance between the intermediate shaft companion flange and the transmission output flange. Use split collar (2) at the pillow block or bearing to locate the shafts.
(13) Move the transmission output shaft to the rear of its end play. Install 6V2042 Alignment Yoke (6), 6V2043 Alignment Bar (7) and the dial indicator on the output shaft flange with the tip of the indicator on the face of the companion flange as shown. Zero the dial indicator at position (A).
(14) Rotate the output shaft and record the indicator reading when the indicator is at positions (B), (C), (D) and again at (A). If a TIR of more than .005" (0.13) is obtained between (B) and (D), tighten horizontal adjustment screw (11) while loosening screw (12) the same amount; or tighten screw (12) while loosening screw (11) the same amount. Adjust the screws until a TIR of .005" (0.13) or less is obtained between (B) and (D).
(15) If a TIR of more than .005" (0.13) is obtained between (A) and (C), loosen or tighten vertical adjustment screws (13), at the rear of the transmission and engine (or transmission if remote mounted), the same amount until a TIR of .005" (0.13) or less is obtained.
(16) Put the tip of the indicator in position on top of the companion flange as shown to check bore alignment. Zero the indicator at position (A). Rotate the transmission output shaft and record the indicator reading at positions (B), (C), (D) and again at (A).
(17) If a TIR of more than .005" (0.13) is obtained between (B) and (D), loosen screws (11) and (14) while tightening screws (12) and (15) the same amount; or tighten screws (11) and (14) while loosening screws (12) and (15) the same amount. Adjust the screws until a TIR of .005" (0.13) or less is obtained between (B) and (D). Make sure all screws are loosened or tightened the same amount in order to retain face alignment.
(18) If a TIR of more than .005" (0.13) is obtained between (A) and (C), loosen screws (13) and (16) the same amount or tighten screws (13) and (16) the same amount until a TIR of .005" (0.13) or less is obtained between (A) and (C). Make sure each screw is turned the same amount in order to retain face alignment.
(19) Remove the alignment fixtures from the intermediate shaft, and move the shafts forward until the output flange pilot starts to engage with the pilot bore in the companion flange. Check the face and bore alignment again, and make adjustments as necessary.
(20) Drill the mounting holes through the engine bed using the holes in the mounting rails or supports as a guide. See the General Information section of this instruction to determine which mounting holes must use fitted bolts and which must use clearance type bolts. Holes for fitted bolts must be interference fit; holes for clearance type bolts must be .06" (1.5) less than the diameter of the holes in the engine mounting rails or supports.
(21) On engines with mounting feet, use steel shims between the mounting feet and the engine bed.
(22) On engines with mounting rails, either steel shims or poured resin shims can be used between the rails and the engine bed.
(23) If steel shims are to be used between the engine rails or supports and the engine bed, see MOUNTING MARINE TRANSMISSIONS AND ENGINES WITH STEEL SHIMS on page 6.
(24) If poured resin shims are to be used between the engine rails and the engine bed, see MOUNTING MARINE TRANSMISSIONS AND ENGINES WITH POURED RESIN SHIMS on page 8.
(25) After the shims have been installed and the mounting nuts tightened, again check the face and bore alignment to be sure that it is correct.
(26) If there are alignment marks on the outside diameter of the companion flange and output flange, rotate the output flange until these marks are in alignment. Move the tailshaft forward until the flange faces are in full contact. Install the flange bolts and tighten them to their specified torque.
(27) After alignment has been completed and all anchor bolts have been tightened to their final torque, the engine crankshaft deflection check, shown on page 31, must be performed on all engines (except D346 and D379 engines) with mounting rails and engine side covers.
Alignment Of Engine To Remote Mounted Marine Transmission
(1) Remove all dirt, burrs, paint and rust preventive from the mating surfaces of the flywheel, coupling and transmission input flange. Install coupling shaft (1) on transmission input flange (2) with bolts, washers and nuts. Install the seal and outer coupling (3) on the engine flywheel.
- Dimension (Z) = .240"
Total coupling clearance = 3.178" - 2.910" = .268"
Dimension (X) = .240" + .134" = .374"
Therefore, for this engine the coupling clearance dimension (X) should be .374" for correct alignment.
(2) During operation, inner coupling (4) must not contact either plate (5) or the face of the flywheel. Correct alignment requires that the inner coupling has approximately the same clearance on both sides. Because of this, it is recommended that the coupling clearance dimension (X) be determined for each engine as follows:
a) Measure the cavity depth, dimension (W).
b) Measure dimension (Y) of inner coupling (4).
c) Measure dimension (Z) of plate (5).
Example: Dimension (W) = 3.178"
Dimension (Y) = 2.910"
(3) Put 4L7464 Silicone Grease on the teeth and bore of coupling (3). Install rubber boots (6). Put silicone grease on the teeth and inside diameter of boots (6). Install inner coupling (4). Put the remainder of the 24 oz. (0.7 kg) of silicone grease in the bore of inner coupling (4). Install seal (7) and plate (5).
(4) Move the engine into position with the transmission. Leave enough gap between inner coupling (4) and coupling shaft (1) to install disconnect spacers (8). Use horizontal adjustment screws (9) and vertical adjustment screws (10) to get approximate alignment between shaft (1) and coupling (4).
(5) Put disconnect spacers (8) in position and install bolts (11) finger tight. Use 6F6922 Depth Micrometer (12) to measure dimension (X). Dimension (X) should be as determined in Step 2. Move the engine toward or away from the transmission as necessary until dimension (X) is correct. Tighten bolts (11). Install and tighten bolt (13) and nut (14) in disconnect spacers (8).
(6) Install 6V2042 Alignment Yoke (15), 6V2043 Alignment Bar (16) and dial indicators (17) and (18) on the coupling shaft as shown.
(7) Put the dial indicators at position (A). Move the engine crankshaft toward the front of the engine to remove all end play. Move the coupling shaft toward the engine to remove all end play. Zero indicator (18). Rotate the crankshaft in the normal direction of rotation, and make a record of the face readings on indicator (18), 90° apart, at (B), (C), (D) and (A). Before taking face readings at each position, make sure all end play is removed from the crankshaft and coupling shaft as described above.
- a) A maximum TIR between (A) and (C) of .010" (0.25) is permitted. The reading at (C) must be plus (+).
- b) A maximum TIR between (B) and (D) of .010" (0.25) is permitted. The readings at (B) plus (D) must equal the reading at (C).
(8) Face alignment as shown by indicator (18) must be as follows:
(9) If the face alignment measurements were not within specification, use the following procedure.
a) If the (A) to (C) TIR was more than .010" (0.25) and the reading at (C) was minus (-), loosen vertical adjustment screws (19) and (20) the same amount as necessary.
b) If the (A) to (C) TIR was more than .010" (0.25) and the reading at (C) was plus (+), loosen vertical adjustment screws (21) and (22) the same amount as necessary.
c) If the (B) to (D) TIR was more than .010" (0.25) and the reading at (B) was less than the reading at (D), loosen horizontal adjustment screw (23) while tightening screw (24) the same amount as necessary.
d) If the (B) to (D) TIR was more than .010" (0.25) and the reading at (B) was more than the reading at (D), loosen horizontal adjustment screw (24) while tightening screw (23) the same amount as necessary.
e) After the face alignment is correct, check the bore alignment as shown on page 28.
(10) Put the indicators at position (A). Zero indicator (17). Rotate the crankshaft in the normal direction of rotation, and make a record of the bore readings on indicator (17), 90° apart, at (B), (C), (D) and (A).
- a) The TIR between (A) and (C) must be .025" ± .010" (0.64 ± 0.25). IMPORTANT: Because the centerline of the crankshaft must be below the centerline of the coupling shaft, the indicator reading at (C) must be plus (+) when the reading at (A) is .000" (0.00) and indicator (17) is installed as shown.
- b) The TIR between (B) and (D) can be a maximum of .005" (0.13). The readings at (B) plus (D) must equal the reading at (C).
(11) Bore alignment as shown by indicator (17) must be as follows:
(12) If the bore alignment measurements were not within specification, use the following procedure:
a) If the (A) to (C) TIR was more than .035" (0.89) with a .000" (0.00) reading at (A) and a plus (+) reading at (C), tighten vertical adjustment screws (19), (20), (21) and (22) the same amount as necessary. Make sure each screw is turned the same number of turns or portion of a turn to retain face alignment.
NOTE: If the reading at (C) was minus (-), the engine is too high and must be lowered by loosening vertical adjustment screws (19), (20), (21) and (22) the same amount as necessary.
b) If the (A) to (C) TIR was less than .015" (0.38) with a .000" (0.00) reading at (A) and a plus (+) reading at (C), loosen vertical adjustment screws (19), (20), (21) and (22) the same amount as necessary. Make sure each screw is turned the same number of turns or portion of a turn to retain face alignment.
NOTE: If the reading at (C) was minus (-), the engine is too high and must be lowered by loosening vertical adjustment screws (19), (20), (21) and (22) the same amount as necessary.
c) If the (B) to (D) TIR was more than .005" (0.13) and the reading at (B) was more than the reading at (D), loosen horizontal adjustment screws (24) and (25) while tightening screws (23) and (26) the same amount. Make sure each screw is turned the same number of turns or portion of a turn to retain face alignment.
d) If the (B) to (D) TIR was more than .005" (0.13) and the reading at (B) was less than the reading at (D), loosen horizontal adjustment screws (23) and (26) while tightening screws (24) and (25) the same amount. Make sure each screw is turned the same number of turns or portion of a turn to retain face alignment.
(13) Check the face and bore alignment again and make corrections as necessary. Check the coupling clearance, dimension (X).
(14) Drill the mounting holes through the engine bed using the holes in the engine mounting rails as a guide. Use dowels or fitted bolts at locations (E) of the mounting rails. Clearance type bolts must be used at all other locations. The holes for the dowels or fitted bolts must be an interference fit. Holes for clearance type bolts must be .06" (1.5) less than the diameter of the holes in the engine mounting rails.
(15) Either steel shims or poured resin shims can be used between the engine rails and engine bed or between the supports for the remote mounted transmission and the engine bed.
(16) If steel shims are to be used, see MOUNTING MARINE TRANSMISSIONS AND ENGINES WITH STEEL SHIMS on page 6.
(17) If poured resin shims are to be used, see MOUNTING MARINE TRANSMISSIONS AND ENGINES WITH POURED RESIN SHIMS on page 8.
(18) After the shims have been installed and the mounting nuts tightened, again check the face and bore alignment to be sure that it is correct.
(19) If there are alignment marks on the outside diameter of the companion flange and output flange, rotate the output flange until these marks are in alignment. Move the tailshaft forward until the flange faces are in full contact. Install the flange bolts and tighten them to their specified torque.
(20) After alignment has been completed and all anchor bolts have been tightened to their final torque, the engine crankshaft deflection check, shown on page 31, must be performed on all engines (except D346 and D379 engines) with mounting rails and engine side covers.
Checking Engine Crankshaft Deflection
NOTE: The following procedure must be used on all D348, D349, D398 and D399 Engines after alignment of the marine transmission and engine, and after installation of the shims and anchor bolts. Do this procedure with both a cold engine and a hot engine.
(1) Remove the inspection cover from the side of the cylinder block to expose the crankshaft center main bearing journal. Rotate the crankshaft until the counterweights on the center throw are just past the connecting rods. Install a Starrett Crankshaft Distortion Dial Gauge No. 696 with a No. 696B Balancer Attachment on either side of the center main bearing journal with the indicator pivot points positioned approximately .25" (6.4) from faces (A) and/or (B) as shown.
(2) Zero the dial indicator. Make sure the indicator pivot points are seated properly by rotating the gauge about its own axis until it will hold a zero reading. Continue to rotate the crankshaft from the starting position until the gauge approaches interference with the connecting rod on the opposite side. Continuously observe the gauge reading while rotating the crankshaft through approximately 300° of rotation.
(3) Rotate the crankshaft back to the original starting position. The indicator reading must return to zero at the original starting position in order to make a valid test. If the indicator did not return to a zero reading, the indicator shaft points were not seated and the test procedure must be repeated.
(4) Crankshaft deflection, as measured by a change in dimension (X), must not exceed -.0005" (-0.01) [close in] or +.001" (+0.025) [spread out]. If the change in dimension (X) exceeded these values, cylinder block distortion has occurred due to improper shimming under the mounting rails. Loosen bolts (1) that fasten engine rails (2) to the ship's engine bed. Install the correct thickness of shims as necessary between the rails and engine bed to ensure that each mounting point is carrying its portion of the load. Check face and bore alignment again to be sure that they are correct. Repeat the crankshaft deflection check if the thickness of any of the shims was changed.
Alternate Methods Of Measurement
(A) Checking Shaft Droop
(1) Determine the weight of the companion flange after all machining operations have been performed.
(2) Measure the length of the shaft from the stuffing box or the first bearing aft of the gear to the end of the shaft (flange end). Determine the diameter of the shaft and refer to the nomograph below for the effective overhanging shaft weight.
Effective Overhanging Shaft Weight
(3) Draw a straight line on the nomograph between the applicable shaft diameter and shaft length; where this line intersects the weight line, read the effective overhanging weight.
(4) Add the weight of the companion flange to the effective overhanging shaft weight. This amount is equal to the force required to raise the flange end of the shaft to its true position.
(5) Use a plumbline to locate a mounting point directly above the companion flange. Weld lifting eye (1) to this point. Install a load ring (2), turnbuckle (3) and a nylon sling or chain on the lifting eye and shaft as shown. Adjust turnbuckle (3) until load ring (2) indicates the force determined in Step 4. The shaft must remain in this position throughout all alignment procedures.
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The lifting eye, mounting point, load ring, turnbuckle and sling or chain must be capable of supporting 2000 lbs. (900 kg). |
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(B) Checking Face Alignment
(1) Measure and record the gap between the flanges at positions (B) and (D) with a thickness gauge or depth gauge. The difference between the two readings must not exceed .005" (0.13). Adjust rear horizontal adjustment screws (1) until a difference of .005" (0.13) or less is obtained.
(2) Measure and record the gap between the flanges at positions (A) and (C). The difference between these two readings must not exceed .005" (0.13). Adjust rear vertical adjustment screws (2) until a difference of .005" (0.13) or less is obtained.
(C) Checking Bore Alignment
(1) If both the output flange and companion flange are of equal diameter, place a straightedge (1) across the two flanges at position (B) or (D). If a gap exists between the straightedge and a flange, adjust the horizontal adjustment screws (2) and (3) until the gap is eliminated. Be sure that each screw is turned the same amount to retain face alignment.
(2) If the output flange and companion flange have different diameters, place a straightedge across the larger flange at positions (B) and (D). Use a thickness gauge to measure the gap between the straightedge and the smaller flange at both points. Add both readings and divide by two. This dimension is the gap needed for correct bore alignment. Adjust horizontal adjustment screws (2) and (3) to obtain the correct gap. Be sure that each screw is turned the same amount to retain face alignment.
(3) Place a straightedge (1) across the two flanges at position (A). If the flanges are of equal diameter, adjust vertical adjustment screws (4) and (5) until the gap is eliminated. If the flanges have different diameters, use the gap measurement calculated in step 2. In both cases, be sure each screw is turned the same amount to retain face alignment.