Who is running an Auburn unit? Got some questions.....

[Amelio]

So when I bought my car many years ago the previous owner had put in an Auburn unit.

On a decel the car would feel like I got a slight bump from the rear kinda like a rear acts when the clutches lock up for a second. I recently changed out the GM fluid to Royal purple and that shifting went away on the decel and now does it on a light accel ...LOL... Since there are no clutches I am wondering what is going on?

Its not too big of a deal because under hard throttle it acts fine and does not cause any issues. I have never had a car with an Auburn unit so I am curious to know if this is how they act under normal operation or is there a problem?

 

[1KWIKSIX]

I put an Auburn "Pro Series" in mine a few seasons ago. When I researched it. the standard Auburn looked like it would be marginal in a car putting out much more torque / HP than the stock GN.

I'm not experienceing any such symptoms as you've described. Smooth as can be.
Mine was installed & set up at a tranny specialist as I also needed a new ring & pinion set & wanted to make sure it was set up with proper clearances, back lash, contact foot print, etc, etc. The Auburn supplied posi fluid was used in mine.

I've only put on a few thousand miles since it was installed by am happy with it and cannot tell the difference in operation between this and the factory Eaton Posi that was in the car previously. Keep in mind that my car sees street duty only (at this point in time anyway).

Another one of the locals also had one installed and he beats the living snot out of it as his car sees lots of track time.

Maybe Brad (Beachbum / Scooby) will chime in with his experiences.

 

[GNeric]

If set up correctly, you will not notice anything on acceleration or decel. They are "locked" in the straight ahead position anyway. Only differential action in when turning. If the pinion nut is loose, it can cause what you are describing. BUT, you would have noise along with it from the pattern changing between pinion and ring gear. If the side bearings are loose, you would have noise as well when driving.

 

[Amelio]

hmmmmm interesting....well I have no noise it is quite as can be and I just serviced it last weekend and everything looked in order I did not see anything that jumped in my face that could be a problem. I check the pinion nut and backlash....I did not put a dial gauge on it but I have set up a few rears and the back lash did not seem excessive at all.

It does not do it all the time but it does do it enough for me to question what the hell is going on.

Thanks for the input.

 

[whitehot1]

So when I bought my car many years ago the previous owner had put in an Auburn unit.

On a decel the car would feel like I got a slight bump from the rear kinda like a rear acts when the clutches lock up for a second. I recently changed out the GM fluid to Royal purple and that shifting went away on the decel and now does it on a light accel ...LOL... Since there are no clutches I am wondering what is going on?

Its not too big of a deal because under hard throttle it acts fine and does not cause any issues. I have never had a car with an Auburn unit so I am curious to know if this is how they act under normal operation or is there a problem?

I have a regular Auburn unit that i had installed in 1997 and have never had any kind of problem with it like you describe here. The only maintenance i do to it is keep the gear oil changed regularly and add the store brand limited slip lube.

 

[GNeric]

Check your rear control arm bushings. Make sure they are torqued properly and that the mounts in both the frame and diff housing are not worn out (oval) so that they move front to rear during acceleration and deceleration.

 

[Phoneguy]

Check your U joints as well

Bryan

 

[SCOOBY DOO]

I put an Auburn "Pro Series" in mine a few seasons ago. When I researched it. the standard Auburn looked like it would be marginal in a car putting out much more torque / HP than the stock GN.

I'm not experienceing any such symptoms as you've described. Smooth as can be.
Mine was installed & set up at a tranny specialist as I also needed a new ring & pinion set & wanted to make sure it was set up with proper clearances, back lash, contact foot print, etc, etc. The Auburn supplied posi fluid was used in mine.

I've only put on a few thousand miles since it was installed by am happy with it and cannot tell the difference in operation between this and the factory Eaton Posi that was in the car previously. Keep in mind that my car sees street duty only (at this point in time anyway).

Another one of the locals also had one installed and he beats the living snot out of it as his car sees lots of track time.

Maybe Brad (Beachbum / Scooby) will chime in with his experiences.

As Dave stated I've got an Auburn Pro Series in my car...and I pound the crap out of it most weekends. Cranked a 7.16 out of it this morning in the 1/8th on a 1.6 launch. It takes everything I can throw at it.

 

[Underboost]

I run an Auburn Posi Pro also, 1.42 60ft and the rearend works like it's stock. No problems.

 

[S10xGN]

Son's MCSS did this when a weld on one the Southside bars broke. Took awhile to find it, as the break wasn't obvious...

 

[Amelio]

ok so it seems this is not an Auburn issue......I did suspect a loose control arm bolt at first and went over them and I did inspect my U-joint, however to check the bolt holes to see if they have been worn out I have not.

I guess maybe the next step is to just drop the rear end out of the car and inspect my control arms thoroughly and the bolt holes they mount too.

Thanks everyone!