How hot is your rear?
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From: The Confederacy
How hot is your rear? I just got my car back after having the piece of **** moser 12 bolt rebuilt. It only lasted about 2,000 miles the way Moser set it up. The roaring had gotten so loud that I was acutally wearing earplugs on the drive to work and back. Like I was saying, I got the car back with Richmond 4.30's in it now. They make a good bit of noise, but nothing like the way it was before. The guy that set up my rear said my DS needed to be shortened an inch, so I said go ahead. On the drive home it would vibrate like a SOB above 65mph, so I sent the shaft back and had them rebalance it. I drove the car to work and back today (30 miles each way) and it is smooth until I'm going about 65+ and I let off the gas to coast, and then it vibrates like hell. There is a big mountian I go down and I was coasting down it at 70mph and the rear view mirror was vibrating so bad I could barely see out of it. When I took up the slack and gave the car some gas, the vibration is gone. Also, when I got home I crawled under the car and grabbed the rear end housing. The chunk and diff cover was so hot it burned my hand!! Should it be that hot? It was between 180 and 200*F I'm sure. I'm going to check it with my digital pyrometer when I get to work in the morning. Anybody want to offer insight or suggestions?
Dont have any advise to offer. I just wonder how it is that everyone I talk to says Moser cant set up a rear end if the company depended on it. I would be sick if I payed that much money for a rear that sucked out of the box. I hope your new gears get you right.
Brandon
Brandon
the heat is normal especially since you just had it rebuilt. The tolerances (pinion bearing preload and carrier preload) are tightest when it's fresh. After a couple of heat cycles it should wear in a bit and not be so hot. This is why gears have a break in period, short drives to get up to normal temps and then let cool. You're trying to not cook the fluid while everything is fresh.
There should be no vibe out of a rear end. It's all
just roundy-round, balanced stuff spinning.
Now, a cobbled-up-to-fit differential that's maybe
not quite at the right driveline angle, has u-joints that
aren't happy and bump every half revolution. Find a
driveshaft or suspension resonance with that and you
will pick up s good vibration.
Might be the pinion is a bit sloppy and the pinion comes
in and out depending on whether the ring is being pushed
(accel) or pushing back (decel)? Pushing the nose bearing
in and out of seat? Nose bearing is all that resists the
wobble-force of the u-joint.
The excess wobble of a misaligned driveline can beat up a
crush sleeve, allowing more wobble, beating it up more...
Just idle speculation. But looking at the 12-bolts and the
stocker, they just seem different in the mounts and maybe
geometry, driveline angle is your real hassle.
just roundy-round, balanced stuff spinning.
Now, a cobbled-up-to-fit differential that's maybe
not quite at the right driveline angle, has u-joints that
aren't happy and bump every half revolution. Find a
driveshaft or suspension resonance with that and you
will pick up s good vibration.
Might be the pinion is a bit sloppy and the pinion comes
in and out depending on whether the ring is being pushed
(accel) or pushing back (decel)? Pushing the nose bearing
in and out of seat? Nose bearing is all that resists the
wobble-force of the u-joint.
The excess wobble of a misaligned driveline can beat up a
crush sleeve, allowing more wobble, beating it up more...
Just idle speculation. But looking at the 12-bolts and the
stocker, they just seem different in the mounts and maybe
geometry, driveline angle is your real hassle.
I d check how much of the driveshaft slip yoke is exposed from the tailshaft of the trans it should be no more than an inch if the driveshaft is too short it will vibrate and I wouldnt worry about temp untill 270+
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11 Second Club
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From: Boring Green, Kentucky
gomer, is this the APE chrome moly shaft? Sorry to hear of this problem man, I wish I could offer some insight.
I hope my new shaft doesn't **** things up, right now only loud whine but no vibrations (fingers crossed.)
I hope my new shaft doesn't **** things up, right now only loud whine but no vibrations (fingers crossed.)
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From: Texas
How far does the DS spline stick out? can you measure it? It sounds like it may be too short.
Have you tried rotating the ds 180 degrees in the yolk?
Also really tight U bolts will cause the ds to vibarate.
Have you tried rotating the ds 180 degrees in the yolk?
Also really tight U bolts will cause the ds to vibarate.
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From: The Confederacy
Originally Posted by 2MuchRiceMakesMeSick
How far does the DS spline stick out? can you measure it? It sounds like it may be too short.
Have you tried rotating the ds 180 degrees in the yolk?
Also really tight U bolts will cause the ds to vibarate.
Have you tried rotating the ds 180 degrees in the yolk?
Also really tight U bolts will cause the ds to vibarate.
i had a vibe in my old one would be rather smooth, not perfect, on accel and sucked vibrating donkey ***** on decel at 65ish at 110 it was humming, pulled that bitch out a few times and rotated and it never went away, had it rebalanced still was there, not quite as bad, so i ordered a new one from APE and its smooth as silk now, dont know what to tell you but i think it has to do with the shaft, try rotating and torque it, overtorqueing can cause a vibe as well with the ujoints, if its still there i'd put a fresh set of spicer joints in there(my ape had spicers) and see if that fixes it
good luck
good luck
11 Second Club
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From: Boring Green, Kentucky
How hot is your rear? Well today, I walked in in front of a construction site full of female carpenters, and they all cat-called and whistled at me 
So I would guess......"pretty hot."
Sorry gomer
, but in all seriousness, keep us updated. I am watching this one closely since my APE shaft is on the way and going into my 12 bolt.
So I would guess......"pretty hot."
Sorry gomer
, but in all seriousness, keep us updated. I am watching this one closely since my APE shaft is on the way and going into my 12 bolt. 
Teching In
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From: Missouri
Originally Posted by CTSmechanic
I d check how much of the driveshaft slip yoke is exposed from the tailshaft of the trans it should be no more than an inch if the driveshaft is too short it will vibrate and I wouldnt worry about temp untill 270+
During the setup I replaced all the bearing and seals including the wheel bearings, races, and seals. I set up the pinion depth at .031" and got a great pattern with .009" backlash, and set the pinion nut preload to 25 in/lbs using a solid spacer.
I did a by the book break-in with drives no more than 15 miles for the first 300 miles without any highway speeds. Now however, when I run them on the freeway the temperature just seems to get higher and higher.
I first thought I must have a leak and be low on oil. But I saw no indications of a leak and when I checked the oil level it was still topped off.
I then thought it was the oil and switched from dino to synthetic but the problem still persisted.
Could it be a bad bearing even if the setup is not making any noise? It's even quieter than my OEM gears, and absolutely no drivetrain vibrations.
I've talked to the local dealership but they couldn't tell me what the normal temperature range was. I'm stumped. . .if anyone can help me out I'd really appreciate it.
Thanks.
Doing rearends in a lube shop, most of them would be rather warm to the touch, but never scalding hot. Since heat is a byproduct of friction, I'd assume there would be a problem somewhere if they're getting that hot. The rearend is a giant heatsink, that's entirely too hot for those gears (and posi) to be.
I've done a lot of 10-bolts, and if everything is right, the chunk will not exceed 170-190F (pyrometer checked) on the first few break-in runs. After that, 150-170 seems to be the norm. If the bearing preload is too much,either pinion or carrier, temps will be abnormally high, without making any noise or vibration. (at least until they gave up) I'd be afraid of over 200F, since dino oil will start to oxidize around 240-250 and the pinion seal will harden and leak before long.
Teching In
Joined: Mar 2004
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From: Missouri
Thanks. That exactly the info I needed. Guess I will have to take it apart again and at replace the pinion bearings. The rear cover is never as hot as the front so I assume the carrier bearings aren't too tight.
Cheers!
Cheers!
mine was pretty hot the first few times i drove on it. its fine now. its also DEAD SILENT on the factory moser setup (4.11's). i went 500 miles w/out giving it more than 1/4 throttle for break-in though.
i wouldnt have messed with the driveshaft length though, 1000's of people on here w/ stock driveshafts in moser 12 bolts w/out problems. sorry to hear about all the BS you have been dealing with latley
i wouldnt have messed with the driveshaft length though, 1000's of people on here w/ stock driveshafts in moser 12 bolts w/out problems. sorry to hear about all the BS you have been dealing with latley
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Joined: Dec 2001
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From: Lakeland, FL
I also have an APE DS and Moser, mine sticks out about 1 inch from the output of the tranny, I guess I am lucky so far I have not had any vibrations and my rear is relatively quiet. Ill feel it after my drive home from work today to see how hot it gets.
BTW Gomer I have read alot of your threads about the Moser problems and while I feel for you I always get a good laugh, seems like this **** is never gonna end for you.
Good luck bro.
BTW Gomer I have read alot of your threads about the Moser problems and while I feel for you I always get a good laugh, seems like this **** is never gonna end for you.
Good luck bro.
Originally Posted by 2MuchRiceMakesMeSick
How far does the DS spline stick out? can you measure it? It sounds like it may be too short.
Have you tried rotating the ds 180 degrees in the yolk?
Also really tight U bolts will cause the ds to vibarate.
Have you tried rotating the ds 180 degrees in the yolk?
Also really tight U bolts will cause the ds to vibarate.