Help - Torque Spec for Installing Rear Differential Assembly

[Buckaroo]

I have a 2000 4wd T4R with non-locker rear differential. I am reinstalling the rear differential carrier assembly into the diff housing. There are 10 nuts w/lock washer that thread onto studs mounted in the housing. It looks to me like the FSM says torque spec is 54 ft-lbs for non-locking diff (text and drawing). Against my better judgement, used this and snapped a stud. Currently pulling assembly again to replace stud. I see now the locking diff spec is 18 ft-lbs which seems closer to being right. Can anyone confirm this torque spec for non-locking diff?

thanks,
Buckaroo

 

[mmml4]

The FSM for my 99 says
w/o diff lock 54 ft-lbs
w/ diff lock 18 ft-lbs

 

[SlickmisterN]

Just do 18-20lb/ft.

 

[weekendclimber]

http://docs.google.com/fileview?id=0B4-QOr310iQRYjY5MDQ0NjgtOTc5Ni00YzZhLTk4NjUtYjk1Y2ZiNjMxMTFk&hl=en&invite=COG4vfsI

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[Buckaroo]

Thanks all for confirming the 54 ft-lbs for the diff w/o lock and 18 ft-lbs for diff w/ lock. I do think the FSM is wrong. Does anyone understand why there would be any difference between the no lock and lock torque spec? I do plan on using the 18 ft-lbs in the absence of any clarification but feel like I'm just guessing.
thanks,
Buckaroo

 

[Rushthezeppelin]

Curious do I need the studs also torqued to 18 into the axle housing. Having trouble getting the double nut trick to actually get me to that spec without the double nuts spinning.

 

[alumarine]

Curious do I need the studs also torqued to 18 into the axle housing. Having trouble getting the double nut trick to actually get me to that spec without the double nuts spinning.

Are you sure they need to be torqued?

 

[Rushthezeppelin]

Are you sure they need to be torqued?

That's my question. I'm pretty sure I've read stuff about engine studs not needing to be torqued in due to torque on the nut providing the clamping force but figured it was worth asking for sure. I've never done anything with studs in my shade tree mechanic career but I took them off my elocker axle housing that I'm about to swap in so that I could clean the gasket surface and wanted to make sure I wasn't going to do something that was going to end up with me needing to redo the seal and refill it.

 

[JZiggy]

Typically when installing studs you just have to bottom them out and give it a little snug. Often the threads that go into the surface are cut with a slight interference fit so they kind of lock in.

 

[Rushthezeppelin]

Typically when installing studs you just have to bottom them out and give it a little snug. Often the threads that go into the surface are cut with a slight interference fit so they kind of lock in.

Yeah definitely noticed they were a tight fit, I couldn't thread them by hand. Thanks man, that helps a ton. Going out to the garage right now to clean up the mating surface, put some FIPG red on and get everything buttoned up.

 

[mtbtim]

Yeah definitely noticed they were a tight fit, I couldn't thread them by hand. Thanks man, that helps a ton. Going out to the garage right now to clean up the mating surface, put some FIPG red on and get everything buttoned up.

I'm probably too late with this comment, but along with what [MENTION=148218]JZiggy[/MENTION] said, a little Blue 242 Loctite on the threads that go into the axle housing would help the stud from backing out when the 3rd member needs to come out for some reason in the future. The Blue 242 Loctite is a light hold, so it wouldn't make the stud removal a nightmare like the red loctite would. Also, the reason the studs backed out with the nut removals is there was some corrosion, or the threads on the stud and/or nut weren't perfect. It wouldn't hurt to run a thread restorer over the stud and into the nut of any combo where the nut doesn't smoothly thread onto the stud.

 

[shadow247]

Just to add more fun to the thread.

I shaved off the bottom of the diff/drain plug, so I'm just going to replace the lowest stud on my housing with a bolt, and use that to drain the gear oil. You can swap the Magnet to the Fill Plug, and you will still catch the shavings.

 

[Rushthezeppelin]

I'm probably too late with this comment, but along with what [MENTION=148218]JZiggy[/MENTION] said, a little Blue 242 Loctite on the threads that go into the axle housing would help the stud from backing out when the 3rd member needs to come out for some reason in the future. The Blue 242 Loctite is a light hold, so it wouldn't make the stud removal a nightmare like the red loctite would. Also, the reason the studs backed out with the nut removals is there was some corrosion, or the threads on the stud and/or nut weren't perfect. It wouldn't hurt to run a thread restorer over the stud and into the nut of any combo where the nut doesn't smoothly thread onto the stud.

Yup too late. That said I purposely removed the studs so I could clean all the old paper gasket. Didn't think to loctite them though but with any luck it will be a long time till I'm in there again.