Andrew

I've noticed lately that there is a high pitch whine coming from the rear end. It only happens when decelerating between 55 and 45 mph. While it is making this noise, if the accelerator is pushed, the noise immediately goes away. Any faster or slower, there is no noise. There is not any vibration. Guys, I am puzzled about this one.

killain

The whine is from the posi unit in the rear end, the gears therein. Change the fluid and add the right amount of Posi-oil additive from General Motors and it could go away. If it's only a minor noise I'd forget about it. A lot of posi rear ends make a little noise. :steering:

wombvette

Whines are caused by pinion gears being out of adjustment. You didnt say what year, but this is prominent in the mid 70s to early 80s rears. The general did a poor job setting them up and there are a lot of wear issues also. First you should check the pinion for end play, which sometimes developes with wear or the nut loosening up. Bearing wear is a possible casuse of the pinion whine, but anything further will require dissasembly and proper set up, if the gears are still OK.

Andrew

Thanks for the advice! I'll start with getting new posi lube. If this doesn't work, then I'll look at the rear pinion adjustment. That doesn't sound easy. Thanks again!! :cheers: