Who ever installed your rear end should have verified the distance. It was plain as day to me when I installed my Moser 12 bolt in my car. The DS yolk was almost all the way to the tailshaft. Only a small amount of room before contact was made with the end of the tail shaft. Not enough for hard launches etc.

Personally I don't think this is Moser's responsibility.

Do you install adjustable suspension parts without an alignment or checking their length prior to driving? Would you Install a clutch without aligning the clutch disk? How about adjusting/verifying pinion angle when replacing the rear?

These are all basic things that need to be checked upon replacing a major component of the vehicle.

DaveW

P.S. Now the poor gear setup is Fully Moser's responsibility and when my gears where whining terribly after the first 50-100 miles of install they paid for a local shop to fix the problem.

 

Well I installed my Axle but did not have the luxury of a lift. I will admit I never checked the shafts position relative to the transmission.

Moser does tell you about the other modifications needed for the rear end and that was not a problem. I do think they should admit there is issues regarding the stock length of the driveshaft. I dont hold them financially responsible for the damage but I do hold them responsible as a business to inform their customers of this issue instead of denying there is any problem with this application. I would not be nearly as upset if they would admit this so others like myself do not run into the same problem.

I understand you point about checking the driveshaft but with all the other mods that were included in the installation instructions, I really didnt think of this nor did I think its an issue. It was an expensive learning lesson I will admit. This is why I started this thread is to inform those like myself that may have overlooked this and save them the headache I am going through now.

 

I agree that now that they know about it they should inform customers in their standard install literature (do they even have this? I didn't get any with my rear).

I do agree that this is hardly the first time they have heard about it though.

DaveW

 

This maybe a dumb question but where would you take the driveshaft to have it shortened and how much does it cost??


I just ordered a moser 12 bolt from thuder racing and they didnt say one word about this and i asked them atleast 3x if there was anything I should know about before I install this rear and the guy i talked to didnt say one word about this I have done searches on this board and LS1.com and havent ever seen anything on shorting the driveshaft unless I missed it

Sorry to use your post but i thought since we were on the subject these folks could answer these few questions for me and other who are going to view this post

Thanks

Steve

 

There are places that specialize the driveshaft repair. Its possible a machine shop can do this. I would call around and search for a reputable place. Basically the remove one end of the driveshaft end, cut it down to size and reweld the end back on. I dont know what the cost is since its all rolled into the repair for my car but I did ask how they did this. Also the driveshaft will need to be rebalanced. That is why I would recommend you going to a reputable shop that do this kind of work regularly or simply purchase a custom fit shaft.

 

Tell me about your terrible while. My has while quite extensively since day one. I hear some people say that their 3.73 and 4.11 moser rear ends are pretty quiet. My whines fairly loud under load but is quiet without load. I wonder if my gears are setup "too tight". If you dont mind, kinda tell me about your experience there.

 

I don't know the details about what was wrong, but the shop I ended up taking it to said it was a very poor install. The shop dealt with Moser directly so I don't know what all needed to be fixed, replaced or the cost.

As far as description of the problem, at about 30mph the gears started to whine, by 50-60mph the noise was unbearable. I don't mean unbearable to the old fogie crying about a hint of noise, but unbearable to a very tolerant person (me). This car is not a daily driver so I don't expect it to drive like a caddy. I do expect to be able to hear when I get out of the car after a short drive to the store and back.

Prior to having them reset this was not the case.

DaveW

 

I had my drive shaft shortened at a local machine shop which specialized in drive shafts. I believe the guy charged me $75 or so, and replaced the u-joints at the same time as well as balancing it. Definately shop around because one place wanted $100 for it, and they were unable to balance it there. The guy said that I wouldn't need it except for at high speeds...Well, hello. Take a look at the application!

Jon

 

Looks like Mr. Moser himself is taking a look into this. I am glad he is looking into this and I feel a little better about this situation. It looks as if this was never brought to his attention by his support team. See the email below:


"At the very least we will add something to our instructions telling people to check the driveshaft length. If we can find something consistent and concrete as far as dimensions are concerned then we will provide that information as well.

Thank you,

Moser Engineering"

 

Mine is exactly the same deal. Mine starts around 25-30mph and seems to get worse around 40-50MPH but the faster I go the more ear piercing it gets. It seems to be loud enough to where I bet its pretty loud outside the car.

 

The input on my driveshaft does come alot farther in the tranny with the moser rear-end...What is the correct procedure to ensure the DS is the correct length? My DS yoke is very close to the Output rubber seal on the tranny..I bet I need to shorten mine also from reading this..What do you guys think? Pushing my DS all the way into the tranny output shaft is barely enough room to slide back of the DS into the YOKE of the rear..I have to turn the Yoke a certain way for the u-joints to slide in..

Cody

 

I have posted on this a few times over the last year or so.

IF you go with a stock Yolk that uses small u-joint things seem to be fine.

IF you opted for the Forged 1350 yolk you MUST shorten your DS.

I am a mechinic by trade and just take for granted you check you work before you take a drive. I could barely get my DS in with the rear end hanging so I KNEW it would not last if I did not cut it.

I took the shaft out and installed the yolk into the trans ALL the way. With the car sitting on the rear end with its full wieght I measured the distance bewteen the CENTER of the trans yolk and the Diff yolk. I then sent the measurement and my Drive Shaft to the local shop and had it shortend for $80

This was only temperary till I get new 3 1/2 shaft

As far as the diff noise? I do NOT trust ANYONE but North West Diff. to work on my gears I have the quietest 12 bolt around

 

I shortened mine myself. I used a bandsaw and check and double checked(and triple checked) that the yoke was level. Too a file and deburred the splines and cleaned it thoroughly.

 

So did we determine an approximate length to shorten the driveshaft by. I have a 3.5" alum driveshaft and its WAY too long for the moser!

 

I personally informed Rob Moser of this two years ago when I installed my 12 bolt. He said that he had never heard of this problem previously. I also mentioned I had the LPE aluminum driveshaft and that it was originally a stick car that had been switched to an automatic. H eprobably didn't put much credibility in my situation because of all the variable (I can't blame him for this).

However, they were at least aware of a potential issue. It doesn't make sense that they would deny knowledge of this issue as it is fairly well known. I can understand not having updated documentation as they are not a large business and with the amout of possible problem areas they cannot note everything that could occur.