I have my 12 bolt in the shop because of a horrible whine and vibration. Most I read is because of a bad gear setup.

The mechanic looked and agreed the whine is too un-desirable. Its not a while most can tolerate. I cannot hear my motor run and I have a small exhaust leak on my manifold over the whine!

Could you guys provide some feedback on your experiences on this and how to stop the whine? He says the backlash is .080 which is in tolerance I guess? He says there is no signs of bad bearings...

Any advice would be greatly appreciated. I am to the point where I am ready to part our my performance parts and sell the car!!!! I really deep down don't want to but I am soooo tired of putting $$$$$$ and not being happy with it. PLEASE HELP!

 

I had the same problemit was whining and clunking when I was turning if you have added some limited slip additive do that first if that doesn't work change the fluid, that did it for my car if it still does it your on your own cause I'm not a specialist. hope this helps

 

Most people just add 1 bottle of limited slip additive. 1 bottle is only designed to treat 2 quarts of gear oil. The Moser holds 3 qts. In actaulaty you need 3 qts of fluid and 1 1/2 bottles of GM additive. Changing the fluid after breakin helps to. Hopefully you didn't use synthetic fluid.

 

I havent changed the breakin fluid. I did use conventional gear oil and one bottle of anti slip additive. Any other suggestions? It may be this is all I need to do but this rear was sung at me since day one.

 

Like Jason said..add another .5-1 bottle of limited slip additive..helped alot with mine Also we talked with Moser and they couldnt come up with any reason NOT to run synthetic gear oil..I know several buddies here in Dallas and they run it..

Cody

 

I think you mean .008 backlash that sounds more right to me, Im not an expert but have messed with a few that someone else was setting up. If it's whining it def is a bad gear setup, it shouldn't make any noise at all. There are a few things a shop would check, but it's been prolly a year or 2 since I've fooled with a rear so I dunno exactly what it may be. It's possible that they don't have the right shims in the pinion gear or something else which of course would make it not ride on the ring gear right.
I dunno if just an oil change would help, you may need to take it to a shop that has a good rep, if it whines after they fix it take it back and tell them it still whines.
I've ridden in a couple cars where rears made noise, and I've seen posts were people say that sometimes they do make noise depending on what ratio they get. I don't think a rear should whine at all if setup right and of course if someone remembered to oil it or not. I've seen a rear come out of a racecar that had been in for about 8 years that didn't make a bit of noise and looked practicly new when it came out. Higher ratio went in, same result, no noise.
Also I've heard that synthetic oil will cause a rear to make noise, but it's just something I read one day and am not positive that it is true so dont' take my word for that
Good luck man, don't get too frustrated with it!

 

I will try that. I steered away from synthetic because the install guide with the rear end specifically said not to use it. I know some of those guys at Moser can give different stories. I really doubt synthetic vs conventional gear oil will make any difference in the whine but maybe the anti slip additive will help!

 

added royal purple to my stock rear with no high-tach, and i have no whine. very smooth too, like new

 

I have never used that. I am not sure the consequences of using it on my 12 bolt. Thanks for the post for I will look and see if something like that can be used

 

Anyone else have any suggestions? Moser Tech support is worthless! They are saying having poly bushings are causing the noise which is totally nuts!!

 

The rear is going to whine. That is part of owning a Moser. It says on there web page that the gears are setup for stregnth, not to be quiet. If you had someone check it out, and it checked OK, then put the 3 qts and 1 1/2-2 bottles of GM additive and let it ride. If it makes noise, then that is the way it is. Like I stated, the gears are set for stregnth, not quietness. You cannot compare stock rears to Mosers, it is 2 diffrent things.

 

I dunno if you ment me comparing stock rear to moser or not, but when i was comparing I was comparing the gear whine to a rear in 2 race cars that we setup. one is a dana and one is a 12bolt, those rears should be "setup for strength" and yet if you cut the car off after you go through the top end and roll through they make no whine at all.. the quickest of our cars being in the 5.60's in the 1/8th mile. Thats all I compared to.
I still am not sure that a rear should make noise at all. But if moser claims that they do then I suppose you can't say anything can you? Only thing i can think of that i guess would make noise is the limited slip differential, if the gear is setup right that is.

 

I understand that some whine is acceptable. The shop did say the clearances looked good but they have not pulled the chunk. They also said it was by far the most noisy rear end they ever heard and this is coming from guys who have hotrods and drag them. They are going to try calling Moser themselves because they believe this rear end is not right and agree that Moser should be responsible for this. They did say they would tear it down and reset/repair and gear problems they ran into but this would be out of pocket for me after spending 2,300 for my rear end. Moser had the nerve to tell me the noise was from the poly bushings on my torque arm and LCA's but would not rescend when I told them its whined just as bad as it does not when the factory parts were installed. The fluid has been changed and 1.5 bottles of anti slip additive was included. Its whines just as bad. Its so loud, I can barely hear someone on a cell phone talking to me driving down the road. My gear shop also mentioned all the 12bolts they have setup regardless of gear type were very quiet.

My rear has a eaton Posi differential also. I dunno.... I am not happy with this rear end at all! I would not complain if the whine was not 1/2 as bad as it is. I have read many places that others had to have new gears, bearing, and/or resetup the gears and the whine was eliminated. To me this is neglegence on Moser and I believe they should set up and take care of this problem. Heck, the rear end only has about 1000 miles on it if that.

 

My Moser 12 bolt whined like a **** when I first got it. Incredibly loud....loud like you could hear it outside the car goin down the road loud. It was set up so tight it was boiling the fluid out of the car. I had gears looked at, and it had wore terribly. I called moser and told them that my backlash was at .004 and about the gear being fried. They sent me a new gear and I had it set up correctly. No whine, and it also picked up 2 and 3 mph from the huge amount of drag not being present anymore. Do some searches on Moser 12 bolts, theres been a couple of threads on them now about how loud they are and being set up incorrectly.

 

Yea they should pay for it, but more than likely they are gonna keep trying not to. I recently built a 383 and for the rods crank and pistons i bought one of the eagle rotating assem. well seemed like a good deal till i put the motor together and had to pull it back apart b/c they left some machine marks on the thrust part of the crank. So what it did to the thrust bearing was just grind it off and get shavings all in the motor. Called the place i ordered it from and they said it was prolly something else, check this check that, whatever, I ended up having to take it somewhere to get it polished(hard to find a place to polish an odd part of the crank). Another guy that did the same thing did get them to take the crank back but it shouldn't have happened.. Would have caught it but it's not a usual spot to check on a crank.
I know this has nothign to do with rears but just goes to show you that no one wants to take any responsibility anymore.

Back to your rear.. 1000 miles isn't far at all, if you took it apart you would prolly see pretty good amounts of wear on the ring gear, if setup right they should run for as long as your car runs in my opinion