->Date: Wednesday, September 20, 1995 10:55AM
->
->Aaah. The Dreaded Clunk. First, it is not all that unusual for the
->rear end to be covered in grease. A lot of it is blown back from the
->engine, so it may not originate in the rear end. There are two
->places where Clunk develops, one easy to fix, the other a swine.
->Unfortunately, to discern between the two requires removal of the
->chunk (the gear housing) unless you have a very delicate touch.
->
->There are two mechanisms in a differential. One effects the right
->angle conversion and involves the ring and pinion gears. This is an
->extremely precision setup and if you have excessive wear here you do
->indeed have trouble. There should be a very slight amount of play in
->the clearance between the ring and pinion. This can be determined by
->observing motion of the ring whilst gently rocking the input shaft
->back and forth. (Note that this is very difficult to judge just by
->holding the axles still, as will be developed below). In general the
->spec on the clearance is something less than a millimeter--it's in the
->shop manual. There should be _absolutely_ no lateral play or
->fore-and-aft play in the input shaft. If there is, your pinion
->bearings are shot and replacement is doable but tricky. You also
->might try cleaning the glop off the diffie case behind the input shaft
->shield so that you can watch for leakage there, to see if in fact the
->input shaft seal is shot. You can replace the input shaft seal with
->only a moderate amount of trouble and the only special tool required
->involves a length of angle iron.
->
->The ring gear turns a cage that holds the differential ("spider")
->gears. These in turn bear on the axle gears. This is usualy where
->the clunk develops. Both the spider gears and the axle shaft gears
->bear on thrust washers that wear out. Even a couple of thousandths
->of wear on these washers results in noticeable slop between the input
->shaft and the rear axles. The washers can be gotten from Moss, among
->other vendors, for a few dollars, and are easily replaced once the
->chunk has been removed. Note that in some cases (with a lot of miles
->or bad lubrication) the spider gears themselves are worn to the extent
->that there will be some clunk even with new thrust washers. Ignore
->it. Your car will continue to soldier on. The only warning here is
->to insure that you use a _new_ split pin to anchor the spider gear
->shaft when replacing it. If this shaft comes loose it will
->immediately lock the rear end, which can kill you.
->
->Use 90w EP "extreme pressure" lube in the rear end. Fill until it
->starts oozing out the fill hole. There will always be some leakage,
->which accounts for the goo all over your unit.
-> A. B. Bonds
->
Thanks ... given your input, I going to remove the 'chunk' and see if I
can determine the cause of the *clunk*.
Larry Unger
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