i messed up...

[ratfreak8871]

I slightly overtightened my pinion nut to 35 in. lbs. Time to tear it back down for new crush sleeve, run it, or back it off to 25 in. lbs. (spec)???

[clinebarger]

If this is a high performance build, A pinion spacer & shims should be used in place of the crush sleeve on GM corporate diffs.

10 inch pounds isn't the end of the world, I'm guessing this is with a seal? Try seating the bearing & races if you haven't already, A few taps on the back of the pinion, & a few taps the the yoke with a brass drift will do. Recheck rotational torque. (Rotate pinion between taps)

If it's still at 35 in. lbs., It will run there! Just be easy on the break-in....Drive around the block, Park the truck & let it cool 30 minutes, Repeat 4 or 5 times.

If you just not happy because the specs, Replace the sleeve & try again, I wouldn't recommend un-crushing on a fresh build.

[ratfreak8871]

Thanks Cline. Not too high perf. 454- 480 HP. Yes it is with a seal. Seated bearings before I put the carrier in. I back nut off to 10 in. lbs. and went back to 24 in. This is where I messed up??

[Ironangel]

Originally Posted by clinebarger

If this is a high performance build, A pinion spacer & shims should be used in place of the crush sleeve on GM corporate diffs.

10 inch pounds isn't the end of the world, I'm guessing this is with a seal? Try seating the bearing & races if you haven't already, A few taps on the back of the pinion, & a few taps the the yoke with a brass drift will do. Recheck rotational torque. (Rotate pinion between taps)

If it's still at 35 in. lbs., It will run there! Just be easy on the break-in....Drive around the block, Park the truck & let it cool 30 minutes, Repeat 4 or 5 times.

If you just not happy because the specs, Replace the sleeve & try again, I wouldn't recommend un-crushing on a fresh build.

Exactly what he saidEspecially setting the races with a brass drift.

[cg285]

+2 in 35 in # don't hurt anything. (Don't back it off!)

what is strange to me is this seating thing. drive the cups home, drive or press on the large cone - done. what is there to seat?

[clinebarger]

Originally Posted by ratfreak8871

Thanks Cline. Not too high perf. 454- 480 HP. Yes it is with a seal. Seated bearings before I put the carrier in. I back nut off to 10 in. lbs. and went back to 24 in. This is where I messed up??

480hp with big block torque, I would HIGHLY recommend a pinion spacer & shim set-up!! What diff are you working on?

Once you crush the sleeve to far.....It's DONE, It will never space the bearings with them amount of force it was designed to once you back off the nut.

Originally Posted by cg285

+2 in 35 in # don't hurt anything. (Don't back it off!)

what is strange to me is this seating thing. drive the cups home, drive or press on the large cone - done. what is there to seat?

Sometimes the races don't get seated all the way using drivers on initial install.

[ratfreak8871]

Cline. I'm working on a 12 bolt. Also adding a Detroit truetrac along with the gears. So your thinking I should do away with the crush sleeve and go with the spacer and shims? I'll have to look into that. Thank you OK got a set coming from Ratech. says to start with spacer and 3 shims, torque nut to 125 Ft.lbs. check preload (25 in. lbs.?)

[Ironangel]

Pinion bearing preload for new bearings and gears in a truck-12 bolt is 13 -15 in-lbs...6 - 7 in-lbs (used)

[ratfreak8871]

I've found the specs all over the place from as low as 13 in to as high as 29in. Should I shoot for the middle and go 20 in maybe?

[clinebarger]

The specs I have are the same as Ironangel's (Yukon Gear & Axle specs), I don't know where my factory service manual is right now......But generally the factory rotational torque spec are higher to go along with different break-in procedures.

20-25 in. lbs. is OK on any Corporate differential except a 7.5" (less) or a 10.5" (more), Bigger Dana diffs can call for up to 55 in. lbs.!!

[ratfreak8871]

Thank you for all the help guys! I have all the parts and ready to go but work and weather are keeping me from it right now. I'll have to keep you updated.