LSD Rebuild

[Keven]

Fianlly got the LSD appart. You simply remove the 8 bolts that hold the end cap off, and the whole assembly comes appart very easily. I used a strap wrench to hold the unit and used my electric impact (Nikota $49 from Kragen), and they came off real easy.

It surprised me that there are no springs, and that it was apperently not under any tension. All the internals (except the clutch plates) are keyed, and slip right into the carrier. They simply lift out.

I degreased and cleaned all varnish/crud off all the parts, and sprayed them with WD40 to prevent rust while Im getting the new shims and clutch packs. Im going to order them from OKP.

The whole process is very simple and took only about 1 hour including cleaning time.

One question, could someone tell me the torque spec on the bolts? Also should I use locktite on them?

Here's a picture of the "gutted" carrier

[Keven]

Here's a pic of all the parts that came out...

[Keven]

Finally a picture of the shims and clutch.
The clutch pack is the part with no keys. I think that it is impregnated with Molydium(sp?) to cause friction on the shim plates.

[Keven]

For Completeness here's a pic from DriverJon of an exploded view of the LSD unit.
Jon, thanks again for the image.

[Trav]

Great pics. Does anyone know what is involved in converting and open axle to limited slip?

TD

[Keven]

Trav,

I also wanted to do this instead of buying a new axle. What I found was that lots of parts on the 2L will not fit the earlier non LSD units. The case is different, the axle shafts, and axle tubes are the biggies.
Tons easier to buy a 2L LSD axle than converting an older one.

Alfa did make an LSD unit for the earlier axles, but good luck finding one. The Alfa part number is 105.44.17.043.01, not sure if it is a direct drop into the early axle.

Here's a question, are there any aftermarket LSD units that can be used in an Alfa differential? There are lots of makers out there Eaton, Rieder, Detroit,JDM etc, anyone know if anyone makes one for Alfas? What do you racers out there use?

[Keven]

Just wanted to share this info to all, I was looking for parts for my LSD, and got this note from the ZF rep:


Thank you for your interest in ZF Industries, Inc., especially in ZF limited slip differentials for Alfa Romeo applications.
At this point in time, due to the low volume, ZF Industries, Inc. does not have a replacement or spare parts program for any limited slip differentials in North America. We answer inquiries, such as your email, for limited slip differentials case by case and order the product directly from the factory in Germany, if available. The factory in Germany discontinued the production last year and will only sell the remaining inventory.
Please provide me with the ten-digit part number from the type plate. I will then email or fax (your preference) the exploded views and after you provided me with a list of parts, I will inquire about price and availability in Germany.

If you need further information, do not hesitate to contact me.
Best regards,
ZF INDUSTRIES, INC.
Passenger Car Transmissions
Axel Blaschke - Regional Sales Manager
777 Hickory Hill Drive; Vernon Hills, IL 60061
Email: passcarinfo@zf.com


On another E-mail Axel informed me that the factory has no shim stock, and only 300 clutch discs left. No more will be produced. Order them while you can!!

[turbolarespider]

Kevin
I just went through this for the second time on the turbo Spider...

CLEAN the bolts and the holes- absolutely NO oil, and no cleaner. Torque to 38 ft-lb. BTW, I used a rag in a vice. That thing is quite hard...

And, we re-packed the clutches and plates for less slip. Where there are a 3 shims, replace the middle on with a clutch. To "pre load" it (which one is NOT supposed to do), we used the thickest 4 shims we had. Seemed to work well. But all the power we had chewed up the clutches badly.

Besides Torsen, Quiafe will also not make a gear type LSD unit for us. I think we needed something like 500 for them to make one. I could sell 20...

Eric

[Keven]

Eric,

Thanks for the info. Would you use Lock-Tight on the bolts? Or is this a bad idea?

[PSk]

Quote:

Besides Torsen, Quiafe will also not make a gear type LSD unit for us. I think we needed something like 500 for them to make one. I could sell 20...

[turbolarespider]

Kevin
I don't use locktite. Shouldn't need it, either. When I pulled the spider apart again, they were tight.

And if you consider how the bolts are loaded, it's all in tension, and some of the loading is taken up by a little interference in the parts.

The ring gear bolts are a different story... But I've not messed with them.

Eric