Usage:
D5H, D5H LGP Tractors;
D5H Custom Skidders
Reference: Information Release Memo (IRM), UC 88-24, "New D5H Improved Wear Life Undercarriage."
Reference: Service Magazine; August 7, 1989; Page 1; "Carrier Rollers Available As Dealer-Installed Attachment" on all D5H and D6H Tractors except LGP models.
Description of Change: Improved (upgraded) undercarriage components which have longer wear life are used on all D5H, D5H LGP Tractors and D5H Custom Skidders. Some major changes will allow the upgraded components to significantly increase bushing wear life. These changes include a new stepped bushing and a new sprocket segment with improved profile. A carrier roller is also added to D5H LGP Tractors only.
NOTE: There are no changes to the track links.
Bushings
The stepped bushing:
... Extends bushing life.
... Improves bushing-to-link ratio.
... Decrease undercarriage cost per hour.
The new bushings have a step of 1.5 mm (.06") to provide an increase in the allowable wear to the replacement point. These bushings are carburized, low carbon steel for optimum toughness, wear resistance, and fatigue strength. The increased material will improve wear life as well as the balance of bushing-to-link wear.
Comparison of new and former bushings.
Segments
The new sprocket segment:
... Has longer wear life. ... Improves wear life of bushing.
... Reduces track slap and vibration.
The new (upgraded) sprocket segment has larger pocket openings to match the stepped bushing. Additionally, the new segments are forged to closer profile tolerances. this will reduce break-in wear on both the segments and bushings.
Carrier Rollers
The LGP tractors have a longer length of track and wider shoes than standard models. Carrier rollers are added to the LGP tractors to accomplish three things.
... Help support the additional shoe weight and length of track.
... Aid in maintaining the correct track sag under a variety of underfoot conditions.
... Reduce track slap and noise by smoothing out upper-side track travel.
NOTE: These items have been shown in field tests to extend the wear life of bushings and sprockets on LGP tractors.
The carrier roller for the LGP tractor has a larger and stronger shaft [76 mm (3") diameter] than the carrier roller on the D5B Tractor. The outer shell is the same as the D5B Tractor, therefore, the wear chart for the D5B Tractor may be used to calculate percent of wear on the carrier roller for the D5H LGP Tractor.
Adaptable To: The new sprocket segment and bushing are effective with product identification numbers 1DD680, 9HC252, 4KD492, 2SD525, 8RC1681, 7NC600, 3MD684, and 1YD610. The new bushings and sprocket segments are directly adaptable to allearlier D5H and D5H LGP Tractors. See chart for part numbers.
Bushings
Limited parts inventory of the former bushing will be maintained for approximately two years for low-quantity parts replacement. The new bushing should be used where entire sets are needed.
Segments
When improved (upgraded) link assemblies are installed, new sprocket segments are required. Use the new segments in a complete set. The new segment will provide correct clearance for the new bushing. The new segment will work for both the former and new bushings.
Link Assemblies
The total number of sections (37 for standard tractors, 46 for LGP tractors, and 42 for custom skidders) is the same. Track shoes and mounting hardware are the same and are directly interchangeable.
Carrier Rollers
Use of the carrier roller is effective with D5H LGP Tractors 1DD679, 9HC252, 4KD474, and 2SD500 (except custom skidders). The carrier rollers are adaptable to all earlier D5H LGP Tractors. See Special Instruction, SEHS8995, "Procedure for Installing Carrier Rollers." See chart for part numbers.
NOTE: See Special Instruction SEHS9045, "Procedure for Installing Carrier Rollers" and the reference article for mounting carrier rollers on other D5H Tractors.
Track Adjustment
CORRECT TRACK ADJUSTMENT CANNOT BE OVEREMPHASIZED! Wear tests on Series H Tractors show a 30% improvement to bushing wear life with correct track sag alone. If the track is too tight, bushing and sprocket wear accelerate. Conversely, a loose track can result in sprocket jumping and damage to the track roller frame. Therefore, it is extremely important to maintain correct track adjustment in order to achieve the maximum undercarriage value.
The track adjustment for standard D5H Tractors without carrier rollers and D5H Custom Skidders remains the same. The track adjustment for D5H LGP Tractors and standard D5H Tractors will change with the addition of the carrier rollers. It will now be similar to D4H and D4H LGP Tractors.
To adjust:
... Add grease until the track is tight.
... Then, open the relief valve to allow the front track roller frame to retract: 10 mm (.4") for D5H LGP Tractors with carrier rollers, and 13 mm (.5") for standard D5H Tractors with carrier rollers.
- Std. D5H Tractors: 100 ± 10 mm (4.0 ± .4").
- Std. D5H Tractors with carrier rollers2: 55 ± 10 mm (2.2 ± .4").
- D5H Custom Skidders: 75 ± 10 mm (3.0 ± .4").
- D5H LGP Tractors2: 55 ± 10 mm (2.2 ± .4").
- Std. D5H Tractors with carrier rollers2: 55 ± 10 mm (2.2 ± .4").
...between the sprocket and the carrier roller
...and, between the carrier roller and the front idler.
2To measure the track adjustment, take the average of these two measurements: