Usage:
768C, 772B, 776 Tractors;
769C, 773B, 777, 785 Trucks
Description of Change: The inner Duo-Cone seal group, used in the service and parking brake groups on the above models, have been improved by using a new toric ring material. The new viton toric rings offer better resistance to heat and aging than the former toric rings.
Additionally, the face load on the 9W2625 Seal Group has been increased by changing the ramp angle from 15° to 8°. Insufficient face load can allow brake cooling oil to transfer into the final drive.
Adaptable As: The new Duo-Cone seal groups using viton toric rings are now in use as shown in the chart. The new seal groups are direct replacements for the former seal groups in all applications except for the 776 Tractor and 777 Truck which require modification.
Refer to Illustration 1 for the location of the new seal groups in rear axle applications.
Illustration 1. Service and parking brake group (777 Truck shown).
Refer to Illustration 2 for the location of the new 9W2627 Duo-Cone Seal Group, part of the 5T3280 Service and Parking Brake Group, located on the front wheels of 785 Trucks.
Refer to Illustration 3 for the information required to modify the 9D9716 Seal Retainer to accept Duo-Cone seals with an 8° ramp angle.
Illustration 2. Location of 9W2627 Duo-Cone Seal Group (785 Truck shown).
Illustration 3. 9D9716 Seal Retainer.