Carrier bearing preload ??

SSGN · 10-26-2024, 07:32 PM

I am assembling an 8.2 10 bolt for a friend. Motive gears,eaton posi and a complete bearing seal kit. How much preload do you use on the carrier. I had to damn near die trying to get the stock carrier out . I reused existing shims and man it was tight going back in. I have to remove because back lash is too much. I cant see the need for that much preload or force on the carrier. Any thoughts?

L.Fite · Yesterday, 01:13 AM

At the factory they used to use a spreader tool to spread the carrier...
There's 4 holes that the tool fits in...
The ones I used to wonder why they were there...

SSGN · Yesterday, 07:56 AM

When changing gears on a street car I always used to put the shims back that I took out as a starting point. I would tap them in with a brass punch. They were always very tight but this set is way too tight.

Robin Lawrence · Yesterday, 09:24 AM

I have done a lot of 8.8" Ford Units in my younger days. If I remember correctly the manual instructed to slide the shims in by hand to set backlash. Once correct backlash was set it said to increase each shim by .004. That was very tight so I mostly increased them by .002 on each side. I had all the shims Ford offered and 2 of many. They got crazy on the pricing so I switched to the adjustable stack shims.

My GM and Mopar buddies all used case spreaders. The solid shims could be installed by driving them in. The stacked shims are a bit more fragile.

Good luck!

Robin

Mark Ugrich · Yesterday, 10:12 AM

You?ll want 20-25 inch lbs of rotating torque, much like setting pinion bearings.When I was a GM tech, occasionally we?d run into a carrier so tight you couldn?t remove it. I?d loosen the bearing caps and put a wrench on one of the ring gear bolts, then put the car in gear to ? walk? it out. I don?t know why they were that tight,the usual result was worn or damaged side bearings.Set the preload first , then add or subtract shims to get your backlash number.

CMcAllister · Yesterday, 04:18 PM

If you don't have the luxury of a good selection of solid shims, I like the good adjustable shim packs. You can measure what came out of it, take a few thou off each side, to get a starting point,

With the pinion set and the turning torque of that known, start with shim packs that allow you to tap them in with some drag, making sure the bearings are seated. Install and snug the caps each time. Checking BL each time, move shim from one side to the other to move the carrier as needed. Fine tune the pattern as you get the BL where it needs to be.

When you get everything where you want it, load an equal amount of shim to each side to get the desired preload. I like to add 6-8 lbin to the total turning torque for a race set. Shim pack should go in snug with a soft wide faced drift or better yet, a tool with an internal radius to fit the shims. Not so tight that you damage the shims. I don't use a spreader to put it together. Final check and confirm the pattern

This has worked for me for years.

10-26-2024, 07:32 PM	#1
SSGN Senior Member Join Date: Feb 2006 Posts: 637 Likes: 123 Liked 135 Times in 49 Posts	Carrier bearing preload ?? I am assembling an 8.2 10 bolt for a friend. Motive gears,eaton posi and a complete bearing seal kit. How much preload do you use on the carrier. I had to damn near die trying to get the stock carrier out . I reused existing shims and man it was tight going back in. I have to remove because back lash is too much. I cant see the need for that much preload or force on the carrier. Any thoughts? __________________ The more people I meet the more I like my dog Kevin

Yesterday, 01:13 AM	#2
L.Fite Member Join Date: May 2020 Posts: 446 Likes: 437 Liked 398 Times in 202 Posts	Re: Carrier bearing preload ?? At the factory they used to use a spreader tool to spread the carrier... There's 4 holes that the tool fits in... The ones I used to wonder why they were there...

Yesterday, 07:56 AM	#3
SSGN Senior Member Join Date: Feb 2006 Posts: 637 Likes: 123 Liked 135 Times in 49 Posts	Re: Carrier bearing preload ?? When changing gears on a street car I always used to put the shims back that I took out as a starting point. I would tap them in with a brass punch. They were always very tight but this set is way too tight. __________________ The more people I meet the more I like my dog Kevin

Yesterday, 09:24 AM	#4
Robin Lawrence Sponsor Join Date: Jan 2002 Location: Galesburg IL. Posts: 167 Likes: 232 Liked 650 Times in 111 Posts	Re: Carrier bearing preload ?? I have done a lot of 8.8" Ford Units in my younger days. If I remember correctly the manual instructed to slide the shims in by hand to set backlash. Once correct backlash was set it said to increase each shim by .004. That was very tight so I mostly increased them by .002 on each side. I had all the shims Ford offered and 2 of many. They got crazy on the pricing so I switched to the adjustable stack shims. My GM and Mopar buddies all used case spreaders. The solid shims could be installed by driving them in. The stacked shims are a bit more fragile. Good luck! Robin __________________ STK 308 SS 3088

Yesterday, 10:12 AM	#5
Mark Ugrich Member Join Date: May 2011 Location: Auburndale,Florida Posts: 211 Likes: 22 Liked 60 Times in 34 Posts	Re: Carrier bearing preload ?? You?ll want 20-25 inch lbs of rotating torque, much like setting pinion bearings.When I was a GM tech, occasionally we?d run into a carrier so tight you couldn?t remove it. I?d loosen the bearing caps and put a wrench on one of the ring gear bolts, then put the car in gear to ? walk? it out. I don?t know why they were that tight,the usual result was worn or damaged side bearings.Set the preload first , then add or subtract shims to get your backlash number.

Yesterday, 04:18 PM	#6
CMcAllister Senior Member Join Date: Sep 2006 Location: Fulton County, PA Posts: 567 Likes: 12 Liked 793 Times in 224 Posts	Re: Carrier bearing preload ?? If you don't have the luxury of a good selection of solid shims, I like the good adjustable shim packs. You can measure what came out of it, take a few thou off each side, to get a starting point, With the pinion set and the turning torque of that known, start with shim packs that allow you to tap them in with some drag, making sure the bearings are seated. Install and snug the caps each time. Checking BL each time, move shim from one side to the other to move the carrier as needed. Fine tune the pattern as you get the BL where it needs to be. When you get everything where you want it, load an equal amount of shim to each side to get the desired preload. I like to add 6-8 lbin to the total turning torque for a race set. Shim pack should go in snug with a soft wide faced drift or better yet, a tool with an internal radius to fit the shims. Not so tight that you damage the shims. I don't use a spreader to put it together. Final check and confirm the pattern This has worked for me for years.