The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-08-2017, 09:28 PM   #1
ratfreak8871
Registered User
 
Join Date: May 2007
Location: ALTON, IL.
Posts: 77
i messed up...

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)???
ratfreak8871 is offline   Reply With Quote
Old 03-09-2017, 12:50 AM   #2
clinebarger
Senior Member
 
clinebarger's Avatar
 
Join Date: May 2009
Location: Fort Worth Texas
Posts: 6,135
Re: i messed up...

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.
__________________
2006 Chevy 2500HD, LBZ/Allison 1000

2001 Chevy Camaro, L92/4L65E
clinebarger is offline   Reply With Quote
Old 03-09-2017, 01:06 AM   #3
ratfreak8871
Registered User
 
Join Date: May 2007
Location: ALTON, IL.
Posts: 77
Re: i messed up...

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??
ratfreak8871 is offline   Reply With Quote
Old 03-09-2017, 01:19 AM   #4
Ironangel
Senior Member
 
Ironangel's Avatar
 
Join Date: Feb 2010
Location: Falls City,Nebraska
Posts: 1,160
Re: i messed up...

Quote:
Originally Posted by clinebarger View Post
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.
__________________
Michael Hill, "Ghostrider"
1980 KZ-1000 ST-MKII, "Baby Doll"
72 Chevy C/10 SS-396 w/Comp Cam=268H, Closed Chamber 290 heads, Stage-4 Power Pack (Eagle Red's) 350THM, Beefed up 12-Bolt, Eaton 4:56 Posi, (Diesel Killer) Street Rod LWB "Nasty Sally"
72 Chevy C/10 Rebuilt 350 w/Voodoo-10120701 Cam, Stage-4 350THM, Beefed up 12-Bolt 3:73 Eaton Posi, LWB Wood Bed, (Daily driver, work horse) "Belle"
https://www.facebook.com/michael.hill.12979
Ironangel is offline   Reply With Quote
Old 03-09-2017, 11:46 AM   #5
cg285
Registered User
 
Join Date: Aug 2013
Location: kissimmee, florida
Posts: 841
Re: i messed up...

+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?
cg285 is offline   Reply With Quote
Old 03-09-2017, 10:02 PM   #6
clinebarger
Senior Member
 
clinebarger's Avatar
 
Join Date: May 2009
Location: Fort Worth Texas
Posts: 6,135
Re: i messed up...

Quote:
Originally Posted by ratfreak8871 View Post
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.

Quote:
Originally Posted by cg285 View Post
+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.
__________________
2006 Chevy 2500HD, LBZ/Allison 1000

2001 Chevy Camaro, L92/4L65E
clinebarger is offline   Reply With Quote
Old 03-10-2017, 03:04 AM   #7
ratfreak8871
Registered User
 
Join Date: May 2007
Location: ALTON, IL.
Posts: 77
Re: i messed up...

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.?)

Last edited by ratfreak8871; 03-10-2017 at 03:22 AM.
ratfreak8871 is offline   Reply With Quote
Old 03-10-2017, 11:01 AM   #8
Ironangel
Senior Member
 
Ironangel's Avatar
 
Join Date: Feb 2010
Location: Falls City,Nebraska
Posts: 1,160
Re: i messed up...

Pinion bearing preload for new bearings and gears in a truck-12 bolt is 13 -15 in-lbs...6 - 7 in-lbs (used)
__________________
Michael Hill, "Ghostrider"
1980 KZ-1000 ST-MKII, "Baby Doll"
72 Chevy C/10 SS-396 w/Comp Cam=268H, Closed Chamber 290 heads, Stage-4 Power Pack (Eagle Red's) 350THM, Beefed up 12-Bolt, Eaton 4:56 Posi, (Diesel Killer) Street Rod LWB "Nasty Sally"
72 Chevy C/10 Rebuilt 350 w/Voodoo-10120701 Cam, Stage-4 350THM, Beefed up 12-Bolt 3:73 Eaton Posi, LWB Wood Bed, (Daily driver, work horse) "Belle"
https://www.facebook.com/michael.hill.12979
Ironangel is offline   Reply With Quote
Old 03-10-2017, 02:36 PM   #9
ratfreak8871
Registered User
 
Join Date: May 2007
Location: ALTON, IL.
Posts: 77
Re: i messed up...

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?
ratfreak8871 is offline   Reply With Quote
Old 03-10-2017, 08:50 PM   #10
clinebarger
Senior Member
 
clinebarger's Avatar
 
Join Date: May 2009
Location: Fort Worth Texas
Posts: 6,135
Re: i messed up...

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.!!
__________________
2006 Chevy 2500HD, LBZ/Allison 1000

2001 Chevy Camaro, L92/4L65E
clinebarger is offline   Reply With Quote
Old 03-14-2017, 09:45 PM   #11
ratfreak8871
Registered User
 
Join Date: May 2007
Location: ALTON, IL.
Posts: 77
Re: i messed up...

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.
ratfreak8871 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:05 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 1997-2013 67-72chevytrucks.com