Part 3: The Wheels Are Coming Off

First remove the snap ring that holds the yokes into the differentialhousing. The yokes rest against the pinion shaft, which causes wear andmushrooming of the yoke end where the snap ring goes. The yokes had beenreplaced and the snap rings were intact. Severely worn yokes break thesnap rings, and pieces will float through the differential.

Before removing the ring-and-pinion, check the ring-gear-to-pinionbacklash. This ring-and-pinion set had .007 backlash. It's possible tochange backlash when changing bearings, so keep a record and set thebacklash to previous settings. Changing the backlash plus or minus .002can cause noise.

It's important to mark the position of the bearing caps to avoidbearing-race distortion. Also mark which side they came from; if youplan to reuse the bearing races, put them with their respective capsafter removal. A shim sets backlash between the bearing race anddifferential housing; place it with the cap and bearing race.

An impact wrench works well for removing the pinion flange. The outerpinion bearing is under the pinion flange. When the yoke snap ringsbreak apart, the pieces end up underneath the pinion outer bearing. Inmost cases, the flange and outer pinion bearing require removal toretrieve the pieces.

These are the pinion or "spider" gears. They can be rotated out of thecase after removing the Posi-traction apply plates and springs. ThePosi-traction clutch plates are beneath the larger side gears. Thepinion shaft is pushed out so the plates and pinion gears could beremoved, then pushed back in for photos. You can see the shiny wear bandon the end of the pinion shaft. In most situations, the pinion shaftshould be replaced. As it wears and the case is damaged, the pinionshaft is loose and will break the pinion-shaft retainer bolt.

Use an impact hammer to bend up the tabs on the differential crossmembermount cushions. Once all the tabs are up, the cushions tap out withoutmuch force. The new cushion taps into place and the tabs are bent over.When reinstalling the crossmember, put a light coat of grease in the cupof the cushions so they don't stick.

This is an unusual situation: tapping out the trailing-arm pivot boltswith a long pin punch and small hammer. In many cases, the pivot boltsare seized to the trailing-arm bushing's inner steel sleeve. Whenthey're seized, rust penetrant doesn't work. A reciprocating saw with aneight-blade placed at the shims is the safest solution for removal. Youcan usually remove shims before using the saw. A torch in this area isdangerous because the fiberglass body is close to the frame and a fuelline above the frame.