Eaton posi making noise.....

[bryanw1968]

I installed this unit about a year ago and it was fine as I added the friction modifier at the same time. I recently pulled the cover off to fix a leak. I installed Valvoline 85/90 weight and some friction modifier and it seemed fine. After a few months it seemed to leak out again and start making noise. I'm wondering if the friction modifier never really meshed with the gear oil and that is what's leaking out. In any case, last night I drained it again and put some Lucas 80/90 in it. It says on the label that no friction modifier is needed. Now it is making all kinds of noise when I turn.

[jhow66]

What you are hearing is the fiber clutches grabbing and releaseing. Go to GM and get their additive. Should fix it.

[piecesparts]

Originally Posted by jhow66

What you are hearing is the fiber clutches grabbing and releaseing. Go to GM and get their additive. Should fix it.

Most importante' Get the additive for the posi unit.

[Alex Hayley]

Would it be correct to assume that the posi additive you can pick up at Autozone for example, is not adequate? Should I only use the GM additive?

[bryanw1968]

Originally Posted by Alex Hayley

Would it be correct to assume that the posi additive you can pick up at Autozone for example, is not adequate? Should I only use the GM additive?

The only time my posi never made any noise was when I first installed it and used the GM gear lube right out of the barrel at a GM shop. Then I had to replace an axle and started using "TransX" friction modifier from Autozone. After a few months it would start to make noise and I'd have to add more.
I'm going to go with the GM stuff or maybe try to pick up some of the Eaton additive.

[Alex Hayley]

That is good advise! I just rebuilt my differential and am using the Transx product. I think I will replace the fluid...quickly! Btw...where is the leak in your differential? Reading your post it seems that you believe the Transx product and the leak are related. Is that what you are implying?

[bryanw1968]

Originally Posted by Alex Hayley

That is good advise! I just rebuilt my differential and am using the Transx product. I think I will replace the fluid...quickly! Btw...where is the leak in your differential? Reading your post it seems that you believe the Transx product and the leak are related. Is that what you are implying?

Yes that's what I'm implying. I never had a leak until I started using that stuff.

Also, I just talked to the guys at the local perfromance shop and they recommended what I did when I first put the posi unit in. Circles and or figure 8's in a big parking lot to "un-glaze" the clutches. I'm going to try that before I give up on the Lucas oil because it's supposed to be pretty decent.
I'll post after lunch to see if it worked.

[cdowns]

i use royal purple in rears its worth the few dollars more and doesnt require an additive for posi or locker rears

as far as the leak problem next time you remove cover check to see if the bolt holes are dimpled out causeing the leak from overtighting(10-15ftlbs MAX) by far the most common cause of 12bolt leaks cure by getting new cover

[bryanw1968]

Originally Posted by bryanw1968

Yes that's what I'm implying. I never had a leak until I started using that stuff.

Also, I just talked to the guys at the local perfromance shop and they recommended what I did when I first put the posi unit in. Circles and or figure 8's in a big parking lot to "un-glaze" the clutches. I'm going to try that before I give up on the Lucas oil because it's supposed to be pretty decent.
I'll post after lunch to see if it worked.

O.K. that didn't work. Man it's making a lot of noise and not just clicking. It's making an angry growling noise still. Time to get the friction stuff from GM or try another gear oil like RedLine or Royal Purple I guess

[jhow66]

If it is growling, it is not your posi unit. More like a bearing.

[bryanw1968]

Originally Posted by jhow66

If it is growling, it is not your posi unit. More like a bearing.

Bearings are new and the problem goes away once I add the friction stuff?
Hmm.....

[bryanw1968]

So I just called the Lucas Oil tech support line and they said depending on the application, wear....etc I may still have to add some sort of modifier. He recommended their oil stabilizer which I already have at home so I'll try that and cross my fingers.

[jhow66]

Originally Posted by bryanw1968

Bearings are new and the problem goes away once I add the friction stuff?
Hmm.....

Ok add the Gm stuff (stinks like the devil)

[bryanw1968]

Originally Posted by jhow66

Ok add the Gm stuff (stinks like the devil)

OK so I added the Lucas oil stabilizer and it still is making noise. I'm going the GM shop and get the right stuff and hopefully be done with it. I hope I didn't burn up those clutches or hose my bearings.

[Scott68-93-97]

Use the GM stuff it sticks good and keeps the gear oil from foaming aftermarket anything does not compare. If that wasn't the case GM would just use the aftermarket stuff and put there label on it if it worked better. If you have a newer car under warranty with a posi and you use any aftermarket additives or oil no more warranty, I use GM's 75-140w synthetic with the GM additive with my stock torsion locker in my 97 it has 134,000 and the posi is brand new looking and works great.

[badpeanut]

Do you have the steel clutches or the carbon fiber clutches?

[Alex Hayley]

Bryan, what is your status on the differential? Did the GM additive solve any problems. JHOW is right....as I was putting the additive in I kept looking around for where the dog had crapped.

[bryanw1968]

Originally Posted by Alex Hayley

Bryan, what is your status on the differential? Did the GM additive solve any problems. JHOW is right....as I was putting the additive in I kept looking around for where the dog had crapped.

The GM stuff completely fixed it. Lucas and Redline are amoung the best and state on their label that you don't need to add an additional additive. It was not true in this case. I will from here on out swear by the GM stuff.

[Scott68-93-97]

right on GM stuff is always better but thats not to say lucas and redline arent a bad product

[PICKMUP]

Even the genuine GM stuff isn't always a cure-all. My Blazer has the stock original low mileage Eaton posi. The clutches popped on turns, so I cleaned it out and put in new GM rearend lube and posi additive..........it still pops, so I give up & just drive it.