12-bolt Torque specs? - Chevelle Tech
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post #1 of 9 (permalink) Old Nov 9th, 08, 3:23 PM Thread Starter
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wes
 
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12-bolt Torque specs?

Hiya Team!
Can you fine felles remember what the bearing cap torque specs are on a 67 12-bolt? I found a website that says 60-ft lbs, but I just want to be sure
Thanks TC!
-wes

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post #2 of 9 (permalink) Old Nov 9th, 08, 3:34 PM
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Re: 12-bolt Torque specs?

# Cover Bolt Ft. Lbs. 20
# Pinion Brg. Preload In. Lbs 20-25
# Pinion Brg. Preload In. Lbs 10-15 Used
# Ring Gear Backlash .005-.009
# Ring Gear Bolt to case Ft. Lbs. 90
# Side Brg. Caps Ft. Lbs. 60

http://www.drivetrainspecialists.com/setupspec.html
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post #3 of 9 (permalink) Old Nov 9th, 08, 4:01 PM Thread Starter
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Re: 12-bolt Torque specs?

Thank you sir!

Wes B in utah
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post #4 of 9 (permalink) Old Dec 3rd, 08, 8:21 PM
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Re: 12-bolt Torque specs?

Thank you search feature and Mike!
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post #5 of 9 (permalink) Old Dec 3rd, 08, 11:05 PM
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Re: 12-bolt Torque specs?

90 foot pounds of torque on the ring gear bolts is 2 times too much. The bolts will break or strip the threads. 45 foot pounds is correct for these 3/8 bolts. The other specs are not too far out. I don't set the backlash any tighter than .007 and no more than .009 in most cases. The pinion bearing preload shouild be 19 to 22 inch pounds in my opinion. 60 foot pounds is right for the bearing cap bolts.
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post #6 of 9 (permalink) Old Dec 4th, 08, 1:02 PM
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Re: 12-bolt Torque specs?

Freddie ,it appears that they've changed the site and the specs since I posted.
Apparently someone pointed out the errors.
Thanks for your noticing them.

http://www.drivetrainspecialists.com/setupspec.html

Last edited by Mike; Dec 4th, 08 at 1:39 PM.
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post #7 of 9 (permalink) Old Dec 4th, 08, 9:10 PM
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Re: 12-bolt Torque specs?

The GM service manual also had the same specs in it. About 27 years ago I was putting together my first 12 bolt and I tried to torque the ring gear bolts to 90 foot pounds. Most of them stripped and I think a few broke. I had to buy a new set of bolts.
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post #8 of 9 (permalink) Old Dec 9th, 08, 1:28 PM
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Re: 12-bolt Torque specs?

BGH .question I have one season on a new R&P and posi ..... thinking I should check the pinion nut to ensure it tight .... is that possible with out screwing up preload ...used a spacer not a crush sleeve ............. or should I just check the inch pounds it takes to rotake rear end ......... if so what should that be ??

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post #9 of 9 (permalink) Old Dec 9th, 08, 3:20 PM
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Freddie
 
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Re: 12-bolt Torque specs?

Do you know what the original torque was on the nut? If you used a solid spacer then you should have torqued it to about 200 foot pounds. If you know what torque you used then just go back and torque it again. It shouldn't hurt anything.

There is no way to check the bearing preload on an assembled rear end. The only way to check it is if you remove the axles and differential.
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