ZF LSD differences ?

[Jim Hunter]

Hello to all,

Today I get a used ZF lsd from a 915 box.
After examination it has coarse splined flane inputs and 2 firiction discs per side.
Is there any advantage in performance and/or value compared with the late fine spilned 1 friction disc per side 915 ZF lsd ???

Thank you !

[Bill Verburg]

As long as you need the course splines, yes, the 4 disks are generally preferred over the later 2 disks.

Both are called 40%(usually) but the greater friction surface of the 4 leads to greater torque transfer.

if the friction disks are worn they can be replaced. Guard plasma disks would be a good way to go there.

In addition transfer torque can be influenced by the tolerances when they are set up

[Steve@Rennsport]

Jim,

Thats an early 915 LSD. You must use the special LSD axle flanges for those and they are NLA from Porsche.

What year is your car??