Removal and Disassembly
by John Ironside
(This article was originally published in the July, 2012 issue of the Spark Coil.)
To remove the drive train from the car, you have to support the rear of the car from the frame. To do this, I first put the rear axle on jack stands and removed the wheels. I then removed the muffler to make way for a 4×4 timber support extended between wheel wells under the frame and resting on a second set of jack stands as shown in the photo below.
Next I removed the brake rods and brake shoes and set aside. Small aftermarket shock absorbers connected the rear spring to the axle and proved very difficult to remove. With the jack stands positioned to catch the rear axle, a C-clamp was finally positioned between the spring and perch on each end so the bolts could be driven out. Disconnecting the front was achieved by positioning a support under the universal ball and removing the four bolts. When the drive shaft was pulled free of the transmission, the universal fell on the floor. Inspection showed that the pin connecting the universal to the drive shaft had sheared off and the universal was floating in the drive train (a dangerous arrangement). The maximum recommended movement of the pins in the universal is 0.020 inch, but three of the four pins actually measured about 0.050 inch and the universal should be replaced. Finally the rear axle was free and could slide out from under the car on timber ramps to the garage floor.
The first step in disassembly was to remove the radius rods and set them aside. With the drive shaft in the vertical position, the six bolts around the pinion bearing spool were removed and the drive shaft lifted out of the differential. A drip pan was aligned under the differential and the axle was rotated to the drive shaft opening down position to allow the differential “goo” to drain out over the next couple of days.
Since the universal was already removed, the drive shaft easily pulled out of the drive shaft housing. A brass bushing is pressed into the end of the housing at the universal end to support the drive shaft and I found it to have excessive wear. The pinion bearing was found to have a broken roller. After fixing the universal end of the drive shaft in a vise, the cotter pin and pinion nut were removed from the other end with substantial effort. A few taps with a hammer removed the pinion gear and allowed the pinion bearing to slide off the drive shaft. I then used a solvent to clean the existing parts. To clean the interior of the housing I stapled a rag dipped in solvent to a long stick to remove the debris.
Below is a photo of the parts on the pinion end of the drive shaft. The pinion bearing with the defective roller removed is on the left. The teeth on the pinion gear were badly worn and pinion needed to be replaced. The pinion bearing sleeve is press fit onto the drive shaft and the notch in the sleeve is supposed to fit around the pinion key. The sleeve was pushed too far onto the shaft and was not in alignment. A friend helped me remove the sleeve and dress the threads on the end of the drive shaft. Then the pinion thrust bearings could be removed from the drive shaft and they appeared to be in good shape.
In the next part of this story I will describe the experience of reassembling the drive shaft with new parts.