early 915 LSD 80% spec

[kevingross]

Hey all, I have an early 915 with factory LSD I am rebuilding. How early, not sure, the serial number and model were ground into pavement long ago I am afraid. Mag case, mechanical speedo, so no later than '74. Appears so far unmolested except for radial oil seals at some point in the past (input shaft seal in backwards...). Forty-four years of crud on the outside, happy happy joy joy.

I have the honest-to-gosh paper workshop manuals for the transmission, both the "from 72" set and the Carrera set. I can't find pages in the first that describe the LSD, and the Carrera set covers only what they call the "40%" LSD. What I have, has the four clutch discs, set up for 80%, and the original wavy springs.

Questions: Anyone know what the desired "clearance" is, to use Porsche's word for it: the difference between the case height and the clutch pack height w/o cup springs? And what the target range for breakaway torque is? Did Porsche write this down anywhere? Cheers,

[Matt Monson]

Do you have the 914 manuals? It’s in there and it’s the same differential. 69-71 mag box, 914, and 72-74 915 w/ 7:31

If you don’t email me at gtgears@yahoo.com I’ll walk you through it this weekend.