Usage:
789 (9ZC),
789B (7EK),
793 (3SJ),
793B (1HL) Trucks
Description of Change: The seal retainer for the rear brake housing has been replaced. The new retainer provides increased face load on the Duo Cone Seal used between the brake and final drive oil compartments.
Adaptable To: The new 116-5241 Retainer is a direct replacement for former 106-6536 and 107-8487 Retainers on the 789 and 789B Trucks. This change is effective with 789B (7EK270) Truck and is adaptable to all earlier machines.
The new 118-8395 Retainer is a direct replacement for former 107-8485 Retainer on the 793 and 793B Trucks. This change is effective with 793B (1HL183-186, 1HL191 and 1HL198-Up) Trucks and is adaptable to all earlier machines.
Former retainers can be adapted by machining the front face of the retainer and the addition of a machined spacer. These modifications create the same face load on the duo cone seal as the new retainers.
NOTE: Only those 789 and 793 Trucks with the correct former part number retainer can be modified. Refer to the Illustrations for the part numbers and machining tolerances for the former retainers and dimensions for the new spacers.
Illustration 1. 106-6536 And 107-8487 Retainer Modification For 789 Trucks (A) 430.0 ± 0.5 mm (16.93 ± .02 in). (B) 58.8 ± 0.2 mm (2.31 ± .01 in) (C) Drill two 5.2 mm (.20 in) diameter holes 25.0 mm (.98 in) deep 180 degrees apart. Tap with M6 X 1-6H thread.
Illustration 2. 107-8485 Retainer Modification For 793 Trucks (C) Drill two 5.2 mm (.20 in) diameter holes 25.0 mm (.98 in) deep 180 degrees apart. Tap with M6 X 1-6H thread. (D) 453.0 ± 0.5 mm (17.83 ± .02 in). (E) 56.8 ± 0.2 mm (2.24 ± .01 in).
Illustration 3. Spacer For 106-6536 And 107-8487 Retainer Modification For 789 Trucks (J) Drill two 6.6 mm (.26 in) diameter holes-countersink 15.0 ± 1.0 mm (.59 ± .04 in) X 90 degrees. (K) 6.23 ± .05 mm (.245 ± .002 in). (F) 430.0 ± 0.5 mm (16.93 ± .02 in). (G) 384.50 ± 0.10 mm (15.140 ± .004 in). (H) 500.00 ± 0.10 mm (19.690 ± .004 in).
Illustration 4. Spacer For 107-8485 Retainer Modification For 793 Trucks (J) Drill two 6.6 mm (.26 in) diameter holes-countersink 15.0 ± 1.0 mm (.59 ± .04 in) X 90 degrees. (P) 6.20 ± 0.05 mm (.244 ± .002 in). (L) 453.0 ± 0.5 mm (17.83 ± .02 in). (M) 416.10 ± 0.10 mm (16.380 ± .004 in). (N) 500.00 ± 0.10 mm (19.690 ± .004 in).
Retainer Rework Procedure
1. Machine excess material from the retainer as shown in Illustration 1 or 2.
2. Drill and tap two holes as shown in Illustration 1 or 2.
3. Fabricate spacer. Drill and countersink holes as shown in Illustration 3 or 4.
NOTE: Use material with hardness of BHN 3.7-4.0.
4. Assemble spacer to retainer, using two 9X-6155 Bolts.
NOTE: Apply Loctite® Sealant (Blue) to the threads before assembly. Tighten the bolts to a torque of 12 ± 3 N·m (9 ± 2 lb ft).
