bordin34

I am putting a used LSD trans in my car and when I took off the side cover I noticed that the differential carrier bearing and races are pitted. So I would like to replace the carrier bearings. Are there any special tools needed to do this? Is there a walkthrough anywhere?
Thanks

Eric_Oz_S2

There is a lot of info in this thread.

https://rennlist.com/forums/showthre...ferrerid=68202

KevinGross

If pitted, they do need to be replaced. In replacing them, you need to reshim both bearings to establish preload and free play between the ring (crown) and pinion gears. The book is pretty clear on the numbers and techniques for both. You don't need to use the factory tools, but you will need to accurately measure the preload and free play.

Consider, though, that the carrier bearings are a good bellwether for the rest of the bearings in the gearbox. Split the gear carrier from the diff carrier, take a look at the front pinion bearing's outer race. You are likely to find it's also pitted, esp around the 5 o'clock area.

If the used LSD is a factory clutch type, I would recommend rebuilding it before re-installing. Wear to the pressure rings' ramps, etc., usually creates a need for reshimming. Inspect the friction disks for condition, test the break-away torque against spec. Quite important: check the thrust washers. The tab pressed into them to lock them to the case creates a stress riser that causes them to fracture, and I generally find one or more of them broken. The broken parts have a way of getting into the clutch packs and gouging their surfaces. Oh, and the thrust washers are NLA from Porsche.

Kevin
Catellus Engineering

SalzundPfeffer

I would be happy to answer any questions the best I can. I just did both diff carrier bearings on my 84 over the winter. Not as bad as I thought. Without going into a bunch of detail all I can say is that material mechanics are your friend. I didn't have to use a press to remove or install the bearings and races.

Both races practically fell out when I heated up the cover plate and transmission case with my Mr. Heater garage heater. Installation was a breeze too. Heat up again and place the bearing races in dry ice. Fell right in place. I used a punch to make sure everything was seated once it cooled.

Putting the bearings on the shaft wasn't bad either. Removed with a three-prong puller. Installation: heat bearings (not too much) cool down shaft and slather with some assembly lube. You will at least get the bearings started before the temps equalize. I then used a soft punch and hammer to "walk" the bearing down the shaft until it seated properly.

Note: Make sure you keep track of the shims that are in there. If you are doing a whole new diff, I presume you will go through the process of resetting the lash. I opted not to considering the age of my vehicle.

Also used this thread too: https://rennlist.com/forums/924-931-...x-problem.html

Good luck!

bordin34

Thanks. Do you happen to have the part numbers for the bearing?

SalzundPfeffer

Ordered from Pelican:

Left - 016-409-123-M92 (SKF)
Right - 113-517-185C-M5092 (SKF)

These are for a manual '84. I recommend checking all numbers to be safe since the right and left are different sizes.

bordin34

Do you know of any walkthrough on how to gear the diff carrier out. I am trying to on my bad transmission and got as far as removing the gear selector, the aluminum rear section, and the bolts holding the thirds on the trans together.
Edit: Do I have to remove 5th gear?

SalzundPfeffer

I'm not sure I understand the question completely. Here is a thread I started that I never got around to finishing. But I show some pics of the transmission teardown. The whole gear carrier comes out complete and this will allow you to get the diff out.

https://rennlist.com/forums/924-931-...placement.html

bordin34

My problem is I cant figure out how to get the gear carrier out.

bordin34

I am this far

Edit:
Here is what this race looks like. Its hard to get a good picture of it


re-edit: better pictures. I'm pretty sure these definitely need to be replaced.

bordin34

I took off 5th gear and the whole thing easily came apart.
And KevinGross called it from my other thread. The diff carrier bearing race spun and even fell out when I removed the diff. There were also a ton of upset marks to hold the race in.
Edit: I'm pretty sure this trans was on borrowed time.

bordin34

Got the diff carrier out of my "new" trans. Did not have to remove 5th gear.
Also the inboard carrier bearing appears to be fine with little wear as well as the pinion bearing.

bordin34

Thanks for the help I got the trans back in the car today. Its quiet and shifts great.