I built a ProStreet 89 Trans Am. It has a very good 406, 4 speed auto with 2800 stall converter and a Moser 12 bolt 3:73 rear end. I have aftermarket torque arm and lower control arms. I've got the Eibach lower springs and lower control arm brackets. I HAVE NEVER HEARD A LOUDER REAR END. It is unbearable. You cannot turn the radio loud enough to drown it out. The 12 bolt came with a Richmond 3:73 gear. Moser sent me another 3:73 and I tried it. It was NO better. Richmond sent me another gear set with the same results. Moser has contended from the beginning that these cars with the aftermarket arms and brackets are extremely loud. This may be true....I don't know, thats why I'm posting this. Has anybody else run into this? I need help. I have a great car but can't stand to drive it. I built it to cruise in. Any suggestions? I spent over 2200.00 on this rear end.

 

The noise in the rear sounds normal for a 12 bolt. My buddy had a strange 12 bolt installed in his LT1. it was assembled by Strange. it was almost unbearable. my 10 bolt with 3.73's is a little loud. the guy i talked to at moser said the 3.73's are the loudest. something about the way harmonics carry through those gears. Also, my torque arm has the solid rod end on it, multiplying the noise. Everybody i talked to said 12 bolts are louder then 10 bolts.

 

Not the first time I've heard of an abnormally loud rear come from Moser. Guy I know stuffed one in his Camaro and it got louder and louder as things heated up. So much so, you had to yell at the passenger to talk. Dunno what ever came of it but Moser agreed something was wrong.

 

Most aftermarket gears, especially richmond have some whine to them. My rearend has US gears, you might want to think about changing the brand of gear, richmond gears are cut slightly different than most making them louder...although it sounds like yours is louder than normal. My moser rearend has a slight whine but nothing thats real loud, sounds like you definately have a problem..it shouldn't be that loud.

 

Thanks for all your input. Moser is sending me another gear set from a different mfg. (my cost). I'll see what that does. If it doesn't get better, I'm not sure what I'll do. I KNOW I'm not going to drive it like that. I do feel like they should warn you about it when you plop down that 2200.00. I would have never gone that route if I had known. Now I don't know what to do.

 

Well, I'm trying to adress the problem again. I've put 3 different mfgs gears in with NO change in noise. I put a 4:10 in with no change in noise. I've had people who are supposed to be some of the best with 12 bolts take a shot at setting it up, with no change in noise. The last one worked on it a couple of weeks and tried every trick he knew and finally said he thought the carrier had to have issues. I want to sell the car and I'm thinking of putting the stock 9 bolt back in. One question first though.....I lowered the car 2", used the LCA brackets, adjustable control arms, adj panhard bar and adjustable BMR trak-pak. All have poly bushings. I replaced the front of the torque arm w/ a rubber bushing w/ no help. Can I have something adjusted wrong to make this much noise???

 

thats funny, my 12 bolt is quieter then the 10 bolt i took out

 

Well I'm pulling the 12 bolt out and putting the stock 9 bolt back in. From what I'm being told my housing or carrier has got to be bad. I just can't take the noise anymore and Moser wants no part of it. I'll just eat it I guess which is what they wanted me to do in the first place. WORST attitude and customer service I've ever seen. Now I know why I've always used Mark Williams and Strange in all my racecars.

 

This is not what i want to hear. I purchased a 12 bolt moser over a year ago and the my car has not even hit the road yet. I had a place in delaware called Rhodes Custom Auto build the rear with 4.11's and eaton posi. i hope my rear doesn't whine. has anybody else had any goodluck with moser? it sounds like all bad luck from what i've been reading.

 

I can't think of anyone who has had success with Moser on a noisy rear end. The most it seems anyone ever gets out of them is a second set of gears.

Moser is 100% convinced that it is the suspension system in these cars that makes the noise. Because of this, you are pretty much at a loss if you buy a new axle from them for this application and it is excessively noisy.

Specifically, Moser has talked themselves in to the idea that the torque arm is acting as a speaker and sounding out the noise by the rear end. What I find very interesting is that they totally ignore the fact that other brands don't have this issue and factory axles with Richmond gears don't have this issue. If a factory axle with noisy gears is quiet in comparison AND other brands don't have this same kind of issue why do they still believe it is the suspension system in common in all three cases?

I would be curious if someone who has a Moser 12-bolt could hook up with a good machinest and measure out the axle in comparison to a factory 12-bolt. I wonder if they have the pinion placement wrong causing all of this. The carrier can't be the cause of all of these complaints, if it were they wouldn't be the only company affected. I also doubt that the carrier bearing bores in the housing are placed wrong. This would be easy enough to see with an alignment bar when they weld up the tubes. If the pinion was a little high or low it could cause issues. A minor side to side error would be easy enough to dial out when setting up the gears. The only other option that seems to make sense is if the pinion was not perpendicular to the axles. Given that the axle is beefed up on the driver's side for the torque arm mount maybe the bores are shifting after the housing is machined, just a few thoughts.

I wouldn't be surprised at all if they drop this application from their offering. The only good part about that is that it will boost sales for Currie and Strange, thus rewarding them for making comparable products that generate fewer complaints. I just hate to see anyone withdraw from this market, it seems so very few people have a serious interest in providing parts.

 

I have a moser 12 bolt and Its not that loud at all. something is transmitting the noise in your suspension setup. Put some of the stock parts back and see if it gets less noisy.

 

For what its worth, my Richmond 3.73's are hella loud, polly bushing in the back, metco LCA's, that kinda stuff does transmit a LOT of extra noise into the car. Even go from regular motor mounts to solid mounts, the car gets a lot louder/buzzier from the motor. Using more solid rear end suspension comonents will amplify the gears, with an already loud rear end, it'll be hella loud. That being said, I'd try a totally different rear to find out.

 

I'm sure this doesn't make a difference, but what spline axles is everybody using? it must be the way the gears are cut but it's strange that several guys have tried different gear companies and still end up with gear whine. just wondering if anybody has tried 31,33, or 35 splines axles and if it made any difference. any complaints from anybody using a 9 inch and using poly type control arms and torque arm?

 

I have poly everywhere with spohn lower control arms and panhard bar. The axles on mine are 30 spline no c-clips.

 

Did you change anything else at the time of changing to the 12bolt? same suspension as w/ 10bolt? I have rod ends on the control arms and panhard bar. They don't seem to transmit any more sound than the poly/ rubber bushing pieces. I DID notice a huge difference after installing the jegster tq. arm w/ poly/solid front mount, LOTS more noise and vibration. I wouldn't call it gear whine though, more like clunks rattles and shakes.

Have you tried adjusting pinion angle? My mud truck had a noisy 12bolt and liked to eat u joints before I changed the angle.