Moser 12 bolt rear problems
Joined: Nov 2001
Posts: 10,023
Likes: 6
From: LT1 land...the "409" of the 90s!
Holey back from the dead! I have had my 12 bolt for over 9 years with no real problems. I TQ the bolts to the correct 100FtLbs using red loctite and check them when I am under the car. I have not lost one yet..cutting 1.3x 60fts!
Gears are an issue. I am now running a set of 1964 GM gears. They are pretty loud when I lift at the end of the track but are usually quiet by the end of the return road.
I will probably go to a 9in in the next year or so and put this one in my wifes car.
BTW I had mine built and maintained localy
Gears are an issue. I am now running a set of 1964 GM gears. They are pretty loud when I lift at the end of the track but are usually quiet by the end of the return road.
I will probably go to a 9in in the next year or so and put this one in my wifes car.
BTW I had mine built and maintained localy
There are lots of people who have Moser 12-bolts with no problems. I've put a few thousand miles on mine and the (UMI trans-mounted) torque arm bolts have never worked themselves loose. I check them during each oil change, just to be safe, and they've been fine so far. Mine is noisy, even without track passes. After doing a lot of reading, it sounds like those of us (note the "us", implying I'm in this group as well) who let Moser assemble and set the pinion depth have problems with noise. Mine came assembled from Moser, then the shop who installed it slid the axles in and bolted everything up for me.
I've had it suggested to me to take it to a local shop with a good reputation for setting up rearends and have them take a look at it. This is on my list of things to do.
I got my 12-bolt for much the same reason you did: I wanted to retain ABS. It sucks that this is what we have to do, but after doing a lot of reading and research, along with asking people who owned these rearends, I came to the conclusion that this is all part of the aftermarket parts game. Some manufacturers' parts bolt right in, while others require extra effort.
However, I don't think pursuing legal action for selling a defective product really fits here. Besides, they can always just rely on the "it isn't OEM, so you can't expect it to fit like OEM" card.
-Mike
I've had it suggested to me to take it to a local shop with a good reputation for setting up rearends and have them take a look at it. This is on my list of things to do.
I got my 12-bolt for much the same reason you did: I wanted to retain ABS. It sucks that this is what we have to do, but after doing a lot of reading and research, along with asking people who owned these rearends, I came to the conclusion that this is all part of the aftermarket parts game. Some manufacturers' parts bolt right in, while others require extra effort.
However, I don't think pursuing legal action for selling a defective product really fits here. Besides, they can always just rely on the "it isn't OEM, so you can't expect it to fit like OEM" card.
-Mike
Moser has had TCS (4 channel -ABS-TCS) out for their nine inch for many years, the ABS only (3 channel) option was just made available this past Fall.
For your 12 bolt I would just tack weld the nuts to the bolt threads once you have them tight, it's quick and easy, and you won't have to worry about them again. Bob
For your 12 bolt I would just tack weld the nuts to the bolt threads once you have them tight, it's quick and easy, and you won't have to worry about them again. Bob
Last edited by kidcamaro98; Mar 11, 2011 at 08:45 PM.
People have tried multiple methods to fix this problem with varying results - the only true fixes seem to be those that involve some sort of physical retention device like safety wire or tack welds. Loctite and locking washers aren't the answer, and you can't just drill the holes out to convert it to a through-bolt setup since you'll end up drilling right into the housing itself, causing a big leak.
It's posible to drill the heads on 6 point bolts for safety wire. Mark the head of the bolts when they are installed with a sharpie so the hole you drill is in a good spot and make sure to put the bolt back in the same hole. A .060 drill bit is strong enough not to break when drilling through the bolt head. Drill straight thru the bolt head, do not try to pick off a corner like a real aircraft bolt.Then safety the bolts with .032 safetywire. When properly safetywired the bolts will not loosen up.
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Verdad Gallardo Well my mechanic used safety wires through the bolt heads and it came loose pretty quick, then again my car has 570 HP and 505 tq at the wheels, bit more vibration then a stock car. He believe you can drill through.. I didnt think there was enough clearance. I'll let you know how it goes.
He'd better be willing to pony up the cash for a new housing if he ends up punching through trying to drill those holes out. If that happens, it will be a tough fix.
If you are considering that, it would probably be just as effective to tack welds the bolts to the torque arm bracket. I didn't really think about it, but with an aftermarket, adjustable torque arm, you could still detach it by just removing the two bolts holding the pivot points in place.
I guess from the sounds of it I would think that you could cut some sheet metal to sit under both bolts on the bottom and on the top. then make two or 3 tabs to stick up. this would look just like the factory style locks on the older v8 manifolds used from the 80-s and back. heck there is so many possibility's
the sheet metal would be similar to this http://cgi.ebay.com/ebaymotors/ws/eB...d=180532378942
the sheet metal would be similar to this http://cgi.ebay.com/ebaymotors/ws/eB...d=180532378942
Last edited by 89 formula350; Mar 12, 2011 at 09:42 PM.
I guess from the sounds of it I would think that you could cut some sheet metal to sit under both bolts on the bottom and on the top. then make two or 3 tabs to stick up. this would look just like the factory style locks on the older v8 manifolds used from the 80-s and back. heck there is so many possibility's
the sheet metal would be similar to this http://cgi.ebay.com/ebaymotors/ws/eB...d=180532378942
the sheet metal would be similar to this http://cgi.ebay.com/ebaymotors/ws/eB...d=180532378942
TECH Regular
Joined: Jun 2009
Posts: 448
Likes: 0
From: new york
drew , just tack em like i told ya man . a tack is easy to grind off when ya need to remove and wont hurt anything . the retaing strap wont hold it back if loctite isnt gonna lol. the problem is the shock load on the rear diff . if the bolts have play in what there holdin its gonna loosen up in time . cheapest and most sure fire way is to tack em in . orrrrr realize what ya did and get a 9 in lol
drew , just tack em like i told ya man . a tack is easy to grind off when ya need to remove and wont hurt anything . the retaing strap wont hold it back if loctite isnt gonna lol. the problem is the shock load on the rear diff . if the bolts have play in what there holdin its gonna loosen up in time . cheapest and most sure fire way is to tack em in . orrrrr realize what ya did and get a 9 in lol
TECH Regular
Joined: Jun 2009
Posts: 448
Likes: 0
From: new york
u will be suprized then ., ya know overtorquing a bolt is almost as bad as having them loose . its all tensil strength ya over torque em and a big load gets to em and they will snap . thats why ya always trq **** right . ya ever see wheel studs break ? most of the time its cause of overtorquing em
Yeah, I wish I would have seen this thread before I bought my last car...gear swap and several other issues later and the mfkr still leaks like an SOB, Moser 12 bolt with 3.73's (now, was 4.10's) and BMR tq arm IIRC (bought it with the tq arm/rear setup)