Greetings. I'm considering buying a Wavetrac limited slip unit and paying a shop to install it in a 3.06 1st generation W126 differential.
I have no experience with limited slip and I'm wondering if any axle modification is required? How does one access the axle end where the circlip retains the axle?
My plan is to install this LSD W126 differential in my W123 wagon and I'm wondering if the W123 axles are a direct fit? I know there might be some driveshaft modification needed as well but I need to figure out the axle stuff first.
Any advice is greatly appreciated. Thanks for reading my post.

If, in fact, the ratio of the intended "W126" center section is 3.06, then it has a ring gear diameter of 210mm, and is known as a "large" center section. However, if the ratio of the chosen unit is 3.07 it will have a ring gear of 185mm diameter, and will be known as a "small" center section.
If it is a "small" (185mm) center section, it will interchange directly with the one in the W123 chassis.
If it is a "large" (210mm) center section, shorter half-shafts (axles) will be required.
The circlips are accessed by removing the cover of the center section.

Thx for the reply. I understand about accessing the circlips in a standard open differential but the Wavetrac LSD unit puzzles me. It appears to be completely enclosed thus blocking off access to the circlips even with the differential cover removed. How is the axle retained and removed?
As for figuring out if axle modification is needed I plan to take a measurements of the distance between the flanges where the two piece axle joins together and see what the difference is between the W123 and W126. I've read one post that claims to have installed 1st generation W126 differential in a W123 and the W123 axles fit. Elsewhere I read that although the W123 differential housing is wider the splined axle stubs are more recessed so flange to flange distance is same with either rear end.
Thanks for reading this post.

I meant the W126 differential housing is wider