I have a 65 Chevy 1/2 ton with the 12 bolt 3.73:1 posi. The rear has always made noise in turns, well it seems I finally fried the clutch pack in the rear end. Speed and/or the severity of the turn don't matter anymore, it always makes noise(except in a straight line). Is there anything I can do to calm this down till I can rebuild it? Are the clutches for the rear still available? If anyone has dealt with this or rebuilt one I could use some help.
[ QUOTE ] are you using the correct posi lubricant? [/ QUOTE ] I'm willing to bet 80w90 gear oil is not posi lube. Who makes it, where can I find it, etc.?
All the additive does is to make the posi partially inoperative. When GM first came out with the posi rearend people were complaining about it chattering while going around corners. They developed a slippery additive which when worked into the clutches allowed them to slip and not make noise. While this eliminated the chatter it also made the posi less effective. An old drag racing "SECRET" in the 60's was to drain the factory posi fluid and go with straight gear lube. With out the slippery stuff the posi grabbed better and resulted in both wheels being lock better when the power was applied. The posi in my '32 chattters at the slightest turn of the wheel. I'm only using regular lube. If you want to minimize the chatter go to a large parking lot (at night) and make about 20 tight circles in one direction, then 20 in the opposite direction. It should work some lube into the plates and get rid of the chatter (or minimize it). Then after a long drive at high speed the lube will be thrown out from between the plates and the chatter will return. The noise and slight shutter only tells you the posi is doing it's job, no harm being done. Frank
The previous post ASSUMES you have the gear lube at the proper level. If not you very well may be frying the rear, the whole thing not just the posi. If the lube is full and you are still annoyed by the noise and shutter get a bottle of additive and add it to the rear. Most auto stores handle it. If not go to the Chevy dealer. Frank
Haven't tried the GM additive but I had to use the fomoco version in several new ford vans we bought at work in '91. They would actually bang and lurch when negotiating a corner after warming up. The ford additive worked well and the expected posi operation seemed undimished...both tires grabbed traction ok.
I am guilty of letting the rear end run low. The seal at the yolk on the rear end was spraying(inconsistently). I finally fixed the seal and speedy sleeved the yolk. Now the spray is fixed, but I may need to rebuild the rear end. I appreciate all the input so far.
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