Differential Assembly

The limited slip Dana Trac-Lok(R) Model 60-1U two-pinion axle and the four-pinion Dana Power-Lok(R) Model 70 have a power flow identical to a conventional rear axle, plus a more direct power flow that automatically takes effect as driving conditions demand. This more direct power flow is from the differential to each axle shaft through the differential clutch packs.

The torque from the ring gear is transmitted through the differential clutch packs, between the differential side gears and differential case. The differential clutch packs are engaged by a preload from dished plates and separating forces from the differential side gears. This occurs as torque is applied through the ring gear.

Model 60 differential clutch packs have clutch discs with concentric grooves and clutch plates with radial grooves. The Model 70 Power-Lok(R) differential has paper-coated clutch packs instead of grooves. Clutch plates of this design should be soaked for 20 minutes prior to assembly in Ford Friction Modifier C8AZ-19B546-A or equivalent meeting Ford specification EST-M2C118-A. Arrangement of these plates and discs is at the option of the vehicle manufacturer. Care should be taken with any of the clutch packs during disassembly to note the arrangement of these components and maintain them exactly as assembled.

Each differential clutch pack is premeasured for correct stack height. Do not separate differential clutch packs and intermix the clutch plates and clutch discs from the differential clutch packs.

In diagnosis of vehicle operators' complaints, two things should be recognized:

^ If, with unequal traction, both wheels slip, the limited slip has done all it can possibly do.

^ In extreme cases of differences in traction, the wheel with the least traction may spin after the limited slip has transferred as much torque as possible to the non-slipping wheel.