I've just got a few simple questions about my rearend if you don't mind. These may be stupid questions, but please... I would like to know. First question. I have a 9 bolt rearend that will only burn both tires when wet. If it's dry I can turn both off the line for a second, then one tire. I plan on pulling the cover tomorrow and changing the fluid to royal purple synthetic with trans-x posi additive. I bought the car over two years ago, and just recently got it running. I don't know when, if ever the fluid has been changed. Will the new fluid and additive fix my problem? Now for the second question. This is the stupid one. If my rearend was run without fluid, what kinds of problems would that cause, and what kind of damage? Thanks for your help!

 

no oil would trash the bearings, axles, and gears at the very least. why would you want to consider not using oil?

 

I wasn't considering not using oil. I was curious what would happen if the oil had drained out after sitting for two years. I'm pretty sure it has oil, because I've driven it for a good 2,000 miles without blowing anything up or seizing anything.

 

The problem is most likely the cones in the unit are damaged. There's a great new tech article on this right here on TGO. I'd order up soem new cones while they are still available. The 9-bolt is a fairly stout rear, and worth keeping as long as you don't have crazy plans for the car.

 

I had a similar problem. The additive and oil change didn't help. If you go on 9-bolt.com they have a posi check you can use to check your posi unit out with. Just jack up one side and put a tq wrench on one of the lugnuts. If it takes more than 35'lbs to turn the wheel then the posi is good. I don't know if it is correct, but that is what is there. What ever you do, keep good oil in that rear. Especially if you have 3.45 gears. I stripped out my ring and pinion a couple months ago. It is nearly impossible to find a set of 3.45s. So, take care of them.
FBird

 

Thanks for the replies guys. I'll try the torque wrench tomorrow morning and see what happens. So if it takes more than 35 lb-ft to turn the wheel then the posi is good, and all I need to do is change the fluid and add the posi additive. Sounds good. I'll see what happens. Thanks.