I posted this in the Gears an axles section and had no help.
When my eaton gets to normal operating temperature it makes a "moaning" sound every time I turn which is really annoying. I added a second bottle of trans-x limited slip additive and it helped a little but not enough. I'm thinking of changing the oil AGAIN to see if it helps. Got any ideas??

 

Did you just notice this after putting your new 20s on? Have you noticed it locking up on low speed sharp turns?

 

No, I noticed this after I changed the plug and gasket b/c it was leaking. About a week later it started making the noise but it's only when it's warmed up. No it doesn't chirp the tires around slow turns.

 

Is this the first time you have used the trans-x addative? I have always used GM addative in mine and havent had any problems. Did you use regular mineral oil or a systhetic?

 

No, The guy who installed it put trans-x and it wasn't doing it. The rear end was leaking so I changed the plug and gasket and that's when it started. I didn't have time to change the parts right away to fix the leak, so I kept adding oil to it until I was abled to fix it. I'm thinking that may have caused it by not having enough limited slip in it.

 

This is a Eaton clutch-pack type posi, right? (Eaton actually makes the stock G80 carriers)

 

correct

 

yup, Eatons have a carbon fiber clutch i believe. obviously you will hear a noise from your rear end if you corner hard. so many people say put the GM additive in with the Eaton. no need to. i was told by 2 popular Eaton dealers to put in 85/140 gear oil without additive. i put in 3 qts of valvoline 85/140 synthetic gear lube, and nothing else. never a problem. i have a valvolone rep that lives about 5-6 doors down from my house, and he agrees.

 

i just had the 410 gears eaton posi in my truck, iknow the guy told me to break the gears in, not to go past 55mph, for 600miles,then you have to change the oil,he told me if i didnt it would make noise, and miss the gears up

 

It doesn't really have to be a hard corner, just any slight turn which would make the Eaton "slip", you'll hear it. I put 80w-90 and was told NOT to put synthetic.