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 "PS4003" 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 May 9, 1997 Service Letter. Changes have been made to the Affected Product.
Termination Date
May 31, 1999Problem
A new seat control bracket needs to be installed on certain 980G Wheel Loaders and 824G, 825G, and 826G Compactors. Excessive lateral loads on the implement control handles may cause slippage of the 1419750 Bracket bolted joint.
Affected Product
Model & Identification Number
824G (4SN322-342)
825G (6RN281-304)
826G (7LN179-251)
980G (9CM377-590 2KR553-1052 2SR1-365 05A11478 , 05A11479, 05A11356, 05A11357)
Parts Needed
Action Required
See the attached Rework Procedure for adding a 1387518 Strap Bracket to the 1166527 Bracket Assembly supporting the right hand controls on the seat. In addition, the three 5V1498 () Locknuts holding the 1419750 Bracket on the seat slide plate are replaced by 1431288 Flanged Locknuts. The machines that need these new bracket are the 980G Wheel Loaders, and 824, 825 and 826 Compactors.
Service Claim Allowances
NOTE: This is a 3-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.
- (1-Rework Procedure)
Rework Procedure
Instructions to add a front support strap bracket to the seat mounted controls support bracket.
Parts to be replaced:
Step-by-step instructions:
NOTE: Use the seat fore/aft, recliner forward/backward, arm rest up/down and arm rest fore/aft adjustments to allow access to the hardware (nuts and bolts).
1. Remove 1275478 and 1275479 Right-Hand Arm Rest Covers, refer to Illustration 1. Illustration 1 shows a perspective representation of the seat without the cushions. The bracket that needs to be replaced is also indicated by the part number 1166527.
2. Remove the four 6V7731 Seat Mount Bolts shown in Illustration 1. This allows the seat to be moved and positioned inside the cab so as to provide enough room to remove the seat upper from its suspension.
3. Remove the 4F4879 Front Stopper Bolt () on the 1247125 Upper Housing of the 1197027 Seat Suspension. The 4F4879 Front Stopper Bolt is shown in Illustration 1.
4. Remove the two 6V9327 Screws on the 4E9173 Upper-Slide Shaft as indicated by the Illustration 2. Note that the screw head is on the outside for the screw at the rear and is on the inside for the screw at the front.
5. Slide the 4E9173 Upper-Slide Shaft out of the 4E6523 Casting bolted to the seat.Be sure to collect the 9U3926 Rubber Dampers (shown in Illustration 2) that may fall when the shaft is removed from the casting.
NOTE: The implement controls box may need to be removed from the 1269578 Bracket Assembly to have the shaft removed from the front.
6. Hold and let the rest of the mechanism fall to the sides gradually until it can be removed from the 4E9173 Lower-Slide Shaft (refer to Illustration 3). Place the controls along with the mechanism on the cab floor.
7. Remove the 4E6523 Aluminum Casting (Illustration 3) from the 1166527 Bracket (Illustration 1) mounted to the seat.The four 8T4136 (M10) Bolts that need to be removed are shown in Illustration 3.
8. Remove the bottom seat cushion (labeled (4) in Illustration 4) from the seat pan. Use a screwdriver to pry the cushion out of the pan as shown in Illustration 4.
9. Lift the seat fore/aft slide handle and slide the seat upper out of its suspension and turn it upside down. Get the seat upper out of the cab for the rework .
10. Replace the three 7U4898 () Screws and 5V1498 Locknuts shown in Illistration 5 with a new set of 7U4898 () Screws and 1431288 Flanged Locknuts. While removing the three locknuts be sure to hold on to the screw and loosen the locknut. Loosening the screw can cause its head to break off. Use the seat back recline lever to adjust the seat back to allow access to the nuts.
11. Torque the three 1431288 Locknuts to a dynamic assembly torque of 50 ± 10 N·m (37 ± 7.5 lb-ft) and a static inspection torque of 27 N·m (20 lb-ft). Remember to hold the screw and torque the nut and NOT vice-versa.
NOTE: Steps (12) to 14) describe the procedure to attach the 1387518 Front Support Strap Bracket between the 1166527 Bracket and the 8Y5982 Seat Pan (refer to Illustration 8).
12. Drill a 12 mm diameter. hole on the 1166527 Bracket to attach the 1387518 Strap Bracket. [You may NOT have to drill this hole if you are working on a seat that has a bracket already with a hole.] To drill the hole on the 1166527, turn the seat upside down, hold the template (Template 1, provided at the end) as shown in Illustration 6 and use the axis shown on the template to locate the center point for the hole (the arrow in Illustration 6 indicates the hole needed) and drill a 12 mm diameter hole.
13. Drill a 12 mm diameter hole on the 8Y5982 Seat Pan to attach the 1387518 Strap Bracket. Hold the template (Template 2, provided at the end) as shown in Illustration 7, use the axis on the template to locate the center of the hole, and drill the 12 mm diameter hole indicated by the arrow in the Illustration 7.
14. Assemble the 1387518 Strap Bracket to the seat (refer to Illustration 8). The 1387518 Strap Bracket has its one end squared and the other rounded. Use a 7U4898 () Bolt and a 7X1387 Washer to locate the square end of the 1387518 Bracket on the 1419750 Bracket. Use a 1431288 Locknut to hold the bolt on the other side. Do not tighten the 1431288 Locknut yet. Use another 7U4898 Bolt and a 7X1387 Washer on the inside and a 1431288 Flange Locknut on the outside of the pan to locate the rounded end of the 1387518 Bracket on the seat pan. Now hold the bolts and tighten the locknuts to a dynamic assembly torque of 50 ± 10 N·m (37 ± 7.5 lb.ft) and a static inspection torque of 27 N·m (20 lb.ft).
15. Replace the plastic christmas tree 8Y5947 Fasteners on the seat pan to allow re-assembly of the seat cushion to the pan. While holding down the seat tilt plate (labeled (6) in Illustration 10) by hand, remove the two cotter pins (labeled as 5) in Illustration 9). Slowly release the spring force against seat tilt plate. Pull up the seat cushion tilt adjustment lever (labeled as 8) in Illustration 10), and remove the seat tilt plate 6). Use a screwdriver to remove the christmas-tree 8Y5947 Fasteners and replace them with the new ones provided. Assemble the seat tilt plate back to the seat pan.
NOTE: There is spring force against the seat tilt plate (6). When the cotter pins (Item 5) are removed and the lever is raised, the spring force will be released. To prevent possible personal injury. retain seat tilt plate (6) by hand when the cotter pins (5) are being removed. Remove the two cotter pins (5) and slowly release the spring force against the seat tilt plate by hand.
16. Assemble the seat cushion back to the seat pan. Make sure that the christmas-tree fasteners line up with the hole on the bottom side of the cushion before pressing it against the pan.
17. Assemble the rest of the components back at their respective locations. Assemble the 4E6523 Casting to the 1166527 Bracket using the four 8T4136 Bolts and tighten them to a standard dynamic torque of 55 ± 10 N·m (40.5 ± 7.5 lb.ft) and a static inspection torque of 31 N·m (23 lb.ft), as was shown previously in Illustration 4. Assemble the seat upper on its seat suspension by sliding it on the rails (Caution not to knock any of the four slide pucks on the slide rails off while assembling the seat back to the suspension). Install the 4F4879 Front Stopper Bolt on the suspension. Make sure that the seat fore/aft mechanism works fine by trying to lock the seat at various positions. Mount the control console and arm rest mechanism back to the seat and assemble the 4E9173 Upper-Slide Shaft to the mechanism with a standard dynamic torque of 47 ± 9 N·m (35 ± 7 lb.ft) and a static inspection torque of 38 N·m (28 lb-ft). Install the two 6V9327 Screws that hold the upper-slide shaft in its place (Dynamic assembly torque: 12 ± 3 N·m (9 ± 2.2 lb.ft) and static inspection torque: 9 N·m (7 lb.ft)). Check to make sure that the arm rest fore/aft mechanism works fine. Assemble the 1275478 and 1275479 Covers back to where they belonged and mount the seat back to the cab with the four 6V7731 Bolts (a dynamic assembly torque of 55 ± 10 N·m (40.5 ± 7.5 lb.ft) and a static inspection torque of 45 N·m (33 lb.ft)) as was shown in Illustration 1.
Illustration 1
Illustration 2
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Illustration 11
Illustration 12