Started having a slight posi noise
 

I have a '55 Bel Air with stock axle with 3.55 gears and a new Auburn Gear posi unit.

I completed my car back in October and now have 1,400 miles on it.

Just 2 weeks ago, I started to get just a slight noise from my posi unit. It only happens in the first 2 turns. Out of my driveway with a left turn, then on to the main street with a right turn. Then it stops completely for the remainder of the trip. If I stop the car for an hour or so and drive it again, it repeats the same thing. If I stop the car for say 10 minutes or so, it won't make the noise.

It's kind of a high pitched noise almost like a break squeak but not quite as high pitched as that.

I used Valvoline gear oil in the case along with the additive that came with the Auburn Gear unit.

Should I try to call Auburn Gear and see if I can find a tech to talk to?

Suggestions?

That's typical for an Auburn. Just add a bottle of Ford or GM limited slip oil additive to it and drive it a while. It should be all right. Don't do anything else to it and don't use any other type of oil additive. I've always had to use 2 bottles of additive for the Auburn.

Thanks.
I'll give that a try. It's cheap and easy to do so if it works, I'll be happy.

I did call Auburn Gear just for interest. Got transferred to a tech and then got voicemail. I left a message but it's been an hour and a half now and no call back yet.

I did a google search on this but most people complain of a grinding noise or chatter but mine is more of a mild squawk.

Got the 4oz bottle of GM additive put in but haven't driven the car yet.

The oil in there was a gray color. Is that normal? Could that be because of the assembly lube the guy used when it was assembled?
You wouldn't think the oil would be dirty after only 1400 miles.

Anyway, I'll report back here if doing this works or not.

I called Auburn back to find out why I didn't get a call back and they said the guy I need to talk to is out sick but he will call me when he gets back to work. They've had a lot of people out with the flu.

Oil shouldn't be gray. It might have a lot of metal floating around in it. The Auburn is well known for this. As the Auburn wears the cones and differential case put a lot of powdered metal into the oil. I had a picture that I would post in a case like this, but I lost all of my pictures when Webshots sold out. The picture shows me dipping my finger into the bottom of a Chevy rear end housing with a worn out Auburn differential. The metal sludge in the bottom of the housing was about 3/8 inch deep.

Before I put the additive in, I sucked out 6 oz of oil to make room for the 4oz bottle.
I put the oil in a clean cup and swished a magnet around in there to see if it picked up any metal. It didn't. (I didn't however put a magnet down into the bottom of the housing.)

I then put the 4oz bottle in and topped it off with new oil.

So, is this gray oil anything to worry about? Is it typical of an Auburn after only 1,400 miles?

I could suck it all out and start over with new oil and 2 bottles of additive. Or go further and pull the pumpkin and clean everything up and re-install but would rather not do that work if it is overkill. What about going with a magnetic fill plug on the fill and clean it often. (This '55 housing doesn't have a drain plug on it.)

What would you do if you were me? I'm hoping you will say just stick to the plan in your first post here.

It's possible that the oil had some type of graphite added to it, or maybe some other additive that made it look like that. I don't know what is in the Auburn oil additive. That might be what it is. I'd let it go for now and see how it holds up. If it still makes the noise then drain it and start over with new oil and 2 bottles of GM or Ford additive.

If you ever decide to do this again, Eaton makes a very good Posi for that rear end. I highly recommend it over the Auburn.

I had the pumpkin put together for me but I installed it and put the oil and Auburn additive in it. So if there was any graphite, It would have had to been assembly lube. But, I don't remember if there were any lube on the internal parts on the pumpkin before I put it in. However, as I remember, the Auburn additive had no color to it.

I'll let it go like you suggest then.
What do you think of a magnetic fill plug idea? Seems like a magnetic drain plug would be better but I don't have that option.

I sure thank you for helping me on this. I saw your profile on another forum that you own a rear end business. Nothing like getting advice from a pro. It's nice of you to do that.

I put a magnet in almost ever rear end that I build. I have a magnetic plug in the rear end in my Camaro. It's always a good idea to try to trap as much metal as possible.

I ran a rear end business for 15 years, but I closed it back in June. Too much to do and not enough time. I'm also a toolmaker for GE aircraft engines. Trying to work 2 jobs is more that I want to do these days. I learned a lot from the rear end business and I don't want to waste that information just because I'm not doing it all the time now.