Pinion nut torque question
Pinion nut torque question Hey guys, so I was planning on buying a 9" but the funds just weren't there (college student) 
but i did find a nice 10 bolt for a great price. I changed out the axle seals and pinion seals. I put the pinion nut back to precisely where I marked it. I can easily move the yoke around and spin the axles but there is no "play" in the gears when i go back and forth with it. All the guides I've found say it should take about around 20 inch pounds to turn everything, just wanted to double check that number with you guys. New seal, same bearing, same crush sleeve, axles installed.
I'd like to get this thing as dialed in as possible before I do the swap. Thanks for the help!
but i did find a nice 10 bolt for a great price. I changed out the axle seals and pinion seals. I put the pinion nut back to precisely where I marked it. I can easily move the yoke around and spin the axles but there is no "play" in the gears when i go back and forth with it. All the guides I've found say it should take about around 20 inch pounds to turn everything, just wanted to double check that number with you guys. New seal, same bearing, same crush sleeve, axles installed.I'd like to get this thing as dialed in as possible before I do the swap. Thanks for the help!
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
NO, NO, NO. You dont need and shouldn't have 20 inch/pounds on used bearings. Used bearings spin very easily. With NEW bearings you are looking to initially set them to 20-25 inch/pounds and then they wear in. 25 inch/pounds compared to a used rear end is super tight. Thats why during break in the bearings generate so much heat. As they wear, the get loose. Setting up used bearings would likely be done with experience and by feel, as I have never seen a spec for used bearing preload. If you dont have a lot of experience and you marked the shaft and nut then thats about as good as you can do. Good luck 
So how do the pros do this? For example the first time I brought in my rear for a pinion seal they said I HAD to put on a new pinion nut. So there would be no marks for them to line up, how would they torque that nut down correctly?
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Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
I personally think you can do it by feel. I also dont think the 10-15 rating given above is right. No need to reload used bearings. Used rear ends are super easy to turn, I would be willing to bet they dont hardly register on a beam style torque wrench.....When you are installing a new crush sleeve and you are clamping it down, the yoke spins very easy and doesnt even show 5 inch pounds. Then all the sudden with like 1/8 a turn of the nut it will jump to 15-20 inch/pounds, thats the bearings loading against each other. By it happening very quick, you know that it is a minute difference you are making that changes bearing preload pretty drastically. I personally have had to take a few crush sleeves back off and reinstall new ones bc you can over tighten them trying to get them perfect so easy. I remember the days of doing front wheel bearings where you had to set the preload with the big nut, too loose or too tight would cause premature bearing wear.....Now we have sealed wheel bearings so the young guys miss out on that experience.
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Verdad Gallardo Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
To remove all doubt here, pull the carrier out, replace both pinion bearings and reinstall with a new crush sleeve and tighten to 20 inch/pounds. Done
I'm no expert. Here's what the GM service manual says:
Best bet is probably to use a new crush sleeve, they only cost $7 or so. That said they are tough to crush. I got lucky and borrowed a nice tool from a local machine shop to hold the flange while I tightened the nut with a breaker bar & pipe.
AXLE ASSEMBLY SPECIFICATIONS
Application..................................INCH Lbs. (N.m)
Pinion Bearing Preload (1)
New Bearing .............................. 15-30 (1.7-3.4)
Used Bearing ............................. 10-15 (1.1-1.7)
Total Assembly Preload (2)
New Bearing .............................. 32-55 (3.6-6.2)
Used Bearing ............................. 16-28 (1.8-3.2)
(1) - Measured with new collapsible spacer and seal,
without ring gear installed.
(2) - Measured at drive pinion gear nut.
Application..................................INCH Lbs. (N.m)
Pinion Bearing Preload (1)
New Bearing .............................. 15-30 (1.7-3.4)
Used Bearing ............................. 10-15 (1.1-1.7)
Total Assembly Preload (2)
New Bearing .............................. 32-55 (3.6-6.2)
Used Bearing ............................. 16-28 (1.8-3.2)
(1) - Measured with new collapsible spacer and seal,
without ring gear installed.
(2) - Measured at drive pinion gear nut.
how is the process of removing the carrier? just those 4 bolts and it comes out in one piece? what about aligning it after it's put back in?
You have to pull the axles to get the carrier out. and yes, the 4 bolts and it comes out. Becareful when pulling, there are shims on either side of it that NEED to go back in the same place.
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
can that be right?
everything I've read would indicate that simply tightening the nut to 20 inch/pounds would not nearly be enough to crush the new sleeve.
do you mean to crank the nut down hard until have have 20 inch/pounds of resistance spinning the yoke with the carrier removed?
Wow! This thread has gotten off course. What you are measuring is the force it takes to rotate the pinion via the nut with a torque wrench on it. Not a click type torque wrench either!
Watch:
http://www.youtube.com/watch?v=8APYO2sZyJU
Watch:
http://www.youtube.com/watch?v=8APYO2sZyJU
Will what I'm dong affect the backlash at all? This is where my problem seems to be, I haven't touched the carrier yet but it seems the gears are right up against each other. Should I get some gear paint and see what kind of pattern is made?