Usage:
NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS8404" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
NOTE: This Revised Service Letter replaces the July 11, 1995 Service Letter (Revised July 1997). Changes have been made to the attached Rework Procedure.
Termination Date
July 31, 2000Problem
The rear track roller frame may crack in the area of the rear bulkhead joint on some D6H LGP Tractors.
Affected Product
Model & Identification Number
D6H LGP (6FC4092-5622 3YG4290-6479 5HF4276-5941 )
Parts Needed
Action Required
See attached rework procedure.
Service Claim Allowances
NOTE: This is a 20-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.
- (1-Rework Procedure)
Rework Procedure
Inspection Procedure
Inspect the track roller frame weld joints for any signs of cracking in the weld joints. Areas to inspect in Area A shown in Illustration 1 are:
1. Inspect the bulkhead weld joint at the rear of the recoil housing. Note if cracks are observed in this weld joint, cut an access hole in the side sheet to inspect/repair the weld joint. Turn the track roller frame over to inspect the lower portion of this weld joint.
2. Inspect the gusset-to-rear bulkhead plate weld.
3. Inspect for vertical cracking on the side plate starting at the corner at the end of the bulkhead weld extending down toward the rollers.
Repair Procedures (if No Cracks Are Found During Inspection)
1. Clean paint from area around gusset.
2. Remove the existing gussets from the track roller frame by cutting them off at the weld joint (Arc Air).
3. Fabricate a formed gusset using 9.5 mm (.375 inch) thick 40,000 psi minimum yield structural steel. Finished dimensions of formed gusset are shown in Illustrations 2. An alternate method that can be used is to install two triangular gussets as shown in attached Illustration 3.
4. Position the new gusset on the roller frame and grind as necessary to fit. Weld the new gusset in place using E7018 low hydrogen electrode. Avoid any welding starts/stops in the lower corner of the gusset at the joint at the bottom. Fill the 45° cutout in this area with weld to prevent water entry under the gusset.
5. Paint the repaired area.
Repair Procedures (if Cracks Are Found During Inspection)
1. See Special Instructions REHS0540 "Repair of the Rear Track Roller Frame at the weld from the Recoil Compartment to the Bulkhead."
NOTE: If the cracks are not completely identified and repaired in compliance with the procedure in the Special Instructions the cracks are likely to develop again.
2. Clean paint from area around gusset.
3. Remove the existing gussets from the track roller frame by cutting them off at the weld joint (Air arc).
4. Fabricate a formed gusset using 9.5 mm (.375 inch) thick 40,000 psi minimum yield structural steel. Finished dimensions of formed gusset are shown in Illustrations 2. An alternate method that can be used is to install two triangular gussets as shown in attached Illustration 3.
5. Position the new gusset on the roller frame and grind as necessary to fit. Weld the new gusset in place using E7018 low hydrogen electrode. Avoid any welding starts/stops in the lower corner of the gusset at the joint at the bottom. Fill the 45° cutout in this area with weld to prevent water entry under the gusset.
6. Fabricate four side reinforcement plates using 9.5 mm (.375 inch) thick 40,000 psi minimum yield structural steel as shown in Illustration 4 (outside plate) and Illustration 5 (inside plate). On the inside plate, fit it up tight to the edge of the equalizer bar ear and may require grinding to get a good fit. Refer to Illustration 8 to see how the support casting for the trunnion is welded to the side sheet.
7. Position the reinforcement plates on the sides of the track roller frame and grind to fit as necessary. These reinforcement plates should be positioned 25 mm (1 inch) below the top edge of the side sheets. On the inboard side, bevel the forward edge of the reinforcement plate to join tightly with the ear for the equalizer bar end pin. The weld on the forward side of this inside plate should tie into the equalizer bar ear plate. Weld in place using E7018 electrode along the outside edge of reinforcement plus the two plug welds. Refer to Illustrations 6 and 7.
8. Paint the repaired areas.
Illustration 1.
Illustration 2.
Illustration 3.
Illustration 4.
Illustration 5.
Illustration 6.
Illustration 7.
Illustration 8.