Usage:
NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
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 "PS8418" 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.
Termination Date
July 31, 1997Problem
The bead seat bands in the demountable rim groups may crack in the area of the drive pockets on certain 994 Wheel Loaders.
Affected Product
Model & Identification Number
994 (9YF74-131, 9YF133-137, 9YF140, 9YF151)
Parts Needed
Not Applicable
Action Required
Parts Stock
Inspect any 109-7088 Bead Seat Bands in Parts Stock. If the bead seat band does not have an "R" or "M" stamped on the driver opposite the driver pocket, it should be reworked. See the attached procedure. After reworking stamp an "M" on the driver opposite the driver pocket.
Affected Product
Previously factory reworked bead seat bands (109-7088) can be identified by an "R" stamped on the driver opposite the driver pocket.
After reworking stamp an "M" on the driver opposite the driver pocket.
See the attached procedure.
Service Claim Allowances
NOTE: This is a 2-hour job.
NOTE: Repair time is only for the actual bead seat band repair. It is recommended that the repair be done at the time of tire change.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.
- (1-Rework Procedure)
Rework Procedure
1. Purpose
This rework is to prevent occurrence of cracking from the weld bead at the end of driver pocket by removing existing weld bead and rewelding.
2. Equipment
Please prepare the following equipment
3. Reworking procedure
- (1) Removing weld beads at area 1 & 5
- ....Remove weld beads by grinding or gouging.
- ....There should be no remaining weld bead at area 5.
- ....Make bevel groove or chamfer of approximately 8 mm on driver pocket side of area 1.
- ....Keep the driver pocket flat on bead seat band.
- ....Remove weld beads by grinding or gouging.
- (2) Removing weld bead at area 2
- ....Remove weld bead by grinding or gouging.
- ....Keep the driver pocket flat on bead seat band.
- ....Remove weld bead by grinding or gouging.
- (3.) Welding at Area 1 & 2
- ....Weld in area 1 & 2 using two passes.Welding should be done from middle to end of the pocket.Make 20-30 mm long and min. 5 mm high pig tail weld.
- ....The first pass should penetrate to the root of the groove and the fillet weld size shall be about 4 mm.
- ....Remove flux well after welding the first pass.
- ....Put the second pass with min. 8 mm of leg length and edge of groove should be covered with weld material.
- ....Leave no under cut and blow holes on weld bead.
- ....Refer to the welding specifications below.
- ....Weld in area 1 & 2 using two passes.Welding should be done from middle to end of the pocket.Make 20-30 mm long and min. 5 mm high pig tail weld.
- (4.) Removing paint and adding weld at area 3
- ....Remove paint at area 3 by grinding or wire brush.
- ....Add weld on the existing weld bead to increase throat thickness.
- ....Leave no under cut welds and blow holes on weld bead.
- ....Remove paint at area 3 by grinding or wire brush.
- (5.) No reworking at area (4)
- (6) Painting
- ....Paint all reworked areas.
Illustration of properly welded driver pocket.