How to remove differential / carrier bearings?

[MC#4]

Can the bearing in the pic be removed and reused? I'm trying to swap them onto my new obx.

[shackwrrr]

Just replace them, "set 11" Is the part number I believe. Change out the races too, just take the extension housings to a transmission shop and have them swap out the races.

http://www.autozone.com/autozone/par...13_0_6534_1277

[MC#4]

Woah, bonus points for the super quick response.

I have a press and should be able to swap races. How critical is bearing preload, is there a spec, how to check it?

[shackwrrr]

Preload is the fun one, Someone else will have to chime in, I dont remember where the shims go but you need to add some. I dont know where people are getting new shims. The OBX isn't made to the best of tolerances so you need to make some major adjustments.

I will try to get the transmission section of the FSM for you that covers all this. The tool is basically a rod that goes into the differential that allows you to measure the turning torque or up down play. You basically install a small shim then assemble the diff, measure the up down play, take the play add a couple .001 then install that many shims for preload then assemble again without ring gear and measure turning torque. if that is good put the ring gear in and button it up, if not add/remove shims to make it tighter/looser then assemble.

---------- Post added at 11:23 PM ---------- Previous post was at 11:19 PM ----------

https://www.dropbox.com/s/t1j24tvw5ympgs3/Transaxle.PDF This will outline everything. The tool you can probably improvise.

---------- Post added at 11:26 PM ---------- Previous post was at 11:23 PM ----------

starts on the bottom of page 33

[86Shelby]

Sonnax(I think that's spelled right) makes a diff shim kit to help you get it set properly. Go ahead and buy new bearings, they will be worth it in the end.

[MC#4]

Thanks alot for the info. I appreciate it!

[A.J.]

When setting the diff preload you take up any slop with shims then you measure turning torque with a 0 to 30ish in/lb torque wrench. I just did it in my SRT-4 auto/limited slip diff build. I think spec for turning torque is 3-8 in/lbs. You add or remove shims from the bearing cup on the ring gear side, opposite of the speed sensor. I used the shim that came with the transmission then had to add Sonnax shims to get the correct preload.

My $200 in/lb torque wrench I bought just for setting preload


I modified an axle stub to set preload on my peloquin LSD


A.J.

[speedfreek500]

To help make things easier, Keep one of the old races and grind it down all around the outside egde. This will allow the race to slide in and out of the housing without needing a press and puller. After it slides in and out you can easily add or remove shims in a heartbeat. When you got the propper pre-load remove the old race and press in the new one and double check it again.

[A.J.]

To help make things easier, Keep one of the old races and grind it down all around the outside egde. This will allow the race to slide in and out of the housing without needing a press and puller. After it slides in and out you can easily add or remove shims in a heartbeat. When you got the propper pre-load remove the old race and press in the new one and double check it again.

If there is a slight variance in the two races that might not work. I didn't have a problem getting a straight punch in there to knock the race out to add or remove shims.

A.J.

[turbovanman²]

If there is a difference in races, its not enough to write home about.

You need a special puller to remove the bearings off the carrier, not worth it to buy one when as said, bearings are cheap. The shims go in the drivers side bearing holder, don't put the seal in until your done. Use a punch to drive the races out, you'll see notch's for that reason, no need to pay anyone to drive them out. You'll probably need .060" or more to set it up properly, they are very sloppy compared to the OE units.

[guhfluh]

My ATSG manual for an A413/31TH says to measure diff endplay, not turning torque?

[shackwrrr]

My ATSG manual for an A413/31TH says to measure diff endplay, not turning torque?

That gets you close then fine tune the turning torque.

[135sohc]

The spec is a .010 preload along with a constant turning torque of 9-14 inch pounds for the MTX.

[turbovanman²]

I use turning torque, I think its more accurate.

[135sohc]

I use turning torque, I think its more accurate.

I thought you just guessed and said good enough


If you follow the procedure in the fsm you use the dial indicator to get it close and then fine tune with the turning torque. The dial indicator comes in handy when your starting from scratch like installing an OBX into a new case. If you just doing a bearing replacement and putting the same parts back together then everything is already really close and the turning torque is probably enough to go with.

[turbovanman²]

I thought you just guessed and said good enough
.

I did, lol, but I've been doing this for years, so I have a good "feeling" on what it should be. When I replaced my trans, I had to use a thicker shim as it turned quite freely.

[MC#4]

Lots of great tips. I'm feeling pretty confident now.

[RoadWarrior222]

Yah, it's not rocket surgery.... it's open heart rocket surgery, I think they use bearings like that on turbine pumps.


Drink plenty of beer, you're gonna need about 30 cans if you need to cut 60 thou worth of shims out of them

[guhfluh]

FWIW, I just checked the turning torque on my a413 differential bearings, since I'm installing a replacement carrier/diff. Since it's an open diff, the turning torque has to be measured by turning the carrier. I looked into the Miller C-4995 special tool and thought I could make something similar.

I used a 1" rubber expandable freeze plug inserted into the axle hole of the carrier and a 1/2" deep socket on the freeze plug's nut directly to my torque wrench. The rubber freeze plug was able to fit in easily and expand easily until tight enough to turn the carrier.

[cordes]

FWIW, I just checked the turning torque on my a413 differential bearings, since I'm installing a replacement carrier/diff. Since it's an open diff, the turning torque has to be measured by turning the carrier. I looked into the Miller C-4995 special tool and thought I could make something similar.

I used a 1" rubber expandable freeze plug inserted into the axle hole of the carrier and a 1/2" deep socket on the freeze plug's nut directly to my torque wrench. The rubber freeze plug was able to fit in easily and expand easily until tight enough to turn the carrier.

Do you have a pic? The turning tool is one of the few I don't own yet.