I put an Auburn posi in my 92 Z28 like 4 months ago and it's already giving me problems. I had a good gear lube in there with a posi additive, always made sure to keep both tires at the same pressure, broke it in properly and everything. The darn thing is slipping now, and there is no excuse for that after like 5,000 miles. I was talking to some friends about my posi woes, and everyone who had ever used an Auburn unit in the past was just as unhappy with their's too.

After careful consideration, I have concluded that Auburn posi units are junk!

 

HUH.

I have one in my '72 with a Vortec head 350 and TH350 in front of it and haven't had a single problem.

 

What type of gear lube did you use.

Jerry

 

I've had an Auburn for years and never had one problem with it. I would buy another one.

 

I had a posi unit installed in my car this summer. While trying to decide which brand to go with, I called several different shops and picked their brains. I was told to stay away from the Auburn posi if my car was to see sufficient track time - something about them not holding up well after repeated trips to the burnout box. Almost every shop I spoke to recommended the Eaton unit instead.

 

yes, everyone i have talked to recomended eaton also, they are also rebuildable, so if it does wear out, unlike the auburn, you can just rebuild it. i got an eaton on e-bay for $100 bucks, ended up not needing to rebuild it either, but even for the rebuild kit, it was only an extra $80 or something like that. if you watch e-bay you can score an eaton for cheap, and them being rebuildable makes them great for ebay, since the condition of the unit doesn't really matter like it does with the auburn.

 

Auburn Pro here.

 

To answer your question Jerry, I was running BG's synthetic gear lube. I think it was 75w90 and I added a bottle of posi additive. There is no excuse for that unit acting up this soon. Right now it's raining here, and the roads are really wet. From 5 mph in 2nd gear I GOT A ONE TIRE FIRE when I tipped into it. Spinning one tire IN THE RAIN on a brand new posi is unacceptable.

 

This may help some....get rid of the synthetic oil, like Auburn's instruction manual tells you. Auburn's posi is a cone type unit and has very little friction area and if you use a very slick oil it will not grip very well. On my car, I always ran standard gear oil and one time I switched to synthetic and the posi stopped working the same day.... Looks like its time to pull the cover and make sure you don't have any broken springs and change the gear oil. I hope this helps.....

Jerry

 

i have an eaton 33 spline posi in moser 12 bolt....its pretty tough

 

get an eaton, simple.

 

Exactamundo!!!

Auburn is very clear in the install manual about not running synthetic lube.

 

Don't need synthetic lube or a "Posi additive"
Only clutch type posi's like an Eaton need an additive.

Probabily your whole problem.

 

The factory used auburn posi's and they recommend an additive.

 

The above statement is only 50% accurate. Auburn specifies the following, page 2 of below link.
http://www.auburngear.com/aftermarke...structions.pdf

Also some educational information linked below.
http://www.auburngear.com/aftermarke.../truestory.pdf

Auburn has always put out a good product, I think its funny to hear people bash their diffs.

 

Use only the GM friction modifier. Even Ford dealers use that instead.

 

eaton...nuf said.

 

i have a auburn posi and its started to act funny, after readin everything here i think the guy used the wrong gear lube, i think ill go buy some good stuff from GM and get the posi additive

 

i have the auburn posi. i haven't had any problems with it. i used carquest gear oil with the GM limited slip additive. i don't really beat on my car that much.

 

just to clarify incase there is some misunderstanding here for anyone (my friend read this post and still did it wrong) When they say GM gear lube in the posts above they mean:

"go to a real GM parts counter and get the friction modifier in the little bottle"!!!!!!!!!

Do not: try to use the BS cheap *** barely/never works half the time "friction modifier" sold in tubes or bottles at the major chain stores or even napa, or try to use "blankety-blank" brand because it says "contains all the friction modifer you need" (horse crap) and thats what your friend used and it worked fine...

thank you

 

okay think ill be off to the GM dealer very soon

 

What they said bout the gear lube.


I've had an auburn pro posi in my Z28 for well over 4 years, 45,000 miles, and at least 400 passes at the dragstrip... It's survived every burnout on everything from street tires to all out slicks.... attached to a 7.5" gearset...

the rear with that posi is tougher than the trans... which wouldn't take 11 sec passes on slicks.. but that rear has


Following directions is your friend

 

I installed an Auburn Pro posi and its absolutley bitchen. That rear is out of my IROC and headed for my 68 C10 now though./

 

i didn't read the whole post but would an eaton diff have came in a 84 berlinetta. cause if so don't use it worn out or you will be buying axles. not fun especially when the locking block decides it doesn't like all the pressure on it and decides it wants to try to come out your dif cover. the reason the block had all the pressure on it was because the ramp broke so it stayed locked the entire time. it could have been worse the half of the block could have went the other way and messed up my brand new 3.73's.
and i have always heard good things about aburn.

 

no

 

that is curious though, because I have seen alot of 3rd gen posi's, and they all look like the eatons with the springs and the clutches. they look fairly thin in the case area. but recnetly I procured a 26 spline stock posi that totally looks like a auburn with its heavy large case. But I didnt notice a "auburn" cast into it. Anyone else seen this in a stock car before?

 

Mine been good for 4 years of racing plus some nitrous too. I used regular gear oil in it and never changed it Need to do that soon

 

Yea, my '82 TA with a 2.93 Posi was an Auburn.
I know Auburn made OEM Posi's for GM, but I'm not sure if they still do it though. They Still do OEM however.

BTW: Aurburn does have a trade in program, for replacing there aftermarket units. I think it's 2 or 3 years from sales? It's not bad, being around 80 bucks or something.

Ron

 

Hey
I had a Auburn in my high mileage IROC. One day I decided to change the gear oil and re-fill with synthetic (Mobile 1). I also added the additive. Within hours the Auburn started making weird noises and banging. I was sure that some part in the rear failed. Took it to my friends shop whole recommended regular 90w gear oil. After I changed the oil the noise went away in minutes and never occured again.
Point: synthetic was to thin/slick for the Auburn

 

i changed my mind. i went to the track last week and now lets just say i have a one wheeler squeeler. i never did any burnouts until i went to the track. it had about 6000mile on it.

 

I have one in my 87 Camaro behind a 400 horse small block and I haven't had a single problem with mine either. Not to question you, but are you sure yours was set up right? You can't just drop them in.

 

Haha. Thats great.. I love when people preach something sucks, because they didnt read the directions..

Thats like complaining that the rear end exploded cuz you didnt set the gears right..

-- Joe

 

.

 

You need to look at your lable of the fluid. It will say limited slip approved. You don't need the extra additive unless it starts to chatter. Then only add some. You are giving it too much lube. As for the which one is better, everyone has an opinion.

 

I would like to know if there is a difference between the OEM and the aftermarket units Auburn has? I just picked up a 4th gen rear and I was pretty sure they had torsens in them but when I pulled the cover it looked like the Auburn posi. Since this was unexpected I had my 2 quarts of Mobil 1 Synthetic gear oil, and I went ahead and did the fluid change.

So can the OEM Auburns use the synthetic fluid?

P.S. the car hasn't been driven yet

 

To be honest with you I don't know about 4th gen. I don't know if 3rd gen comes with alburns. I though they came stock with eatons. You can run with synthetic and see. It mite be too much lubrication. If it goes one legged you will know. If it does I would go back to a normal lube and add a little friction modifier only if it chatters. Thats from my experiences.