Axles

February 16, 2020

Tranny: Mendeola S5R (sequential 5 speed), designed to mate with Porsche 930 CVs
Rear Spindles: Corvette C5.
Axles: corvette C5.
Chris from Active Power Cars was kind enough to provide the 930 CVs & C5 corvette axles, which have the same spline specs as the Porsche 930 CVs…so it was as “simple” as dissembling the inner CVs on from the corvette axles and dropping in the 930 CVs.
Disassembly: I’ve done a few CVs before, and it’s always a mess…so it’s all about preparation and having a work area that can contain the old grease. the hardest part was finding the locking clip…once found, and then choosing the needed clip release tool, the CVs slid off and I could clean everything in short order. The side benefit is taking the OEM CVs apart, as they provide great marbles for the girls to play with.
Inspection: I double checked that the corvette axles were in good shape…no mushrooming or cracked splines. I then inspected the new 930 CVs…while these were new, they had some shape edges and a few Porsche assembly videos recommended taking some sandpaper to smooth out the edges; a perfect job for small hands!
Assembly: triple checking is key…each component of the CV has a specific way to go into place and they are not reversible. It’s very satisfying assembling the star, balls, cage, and housing…to see such a simplistic design that can translate upwards of 800 ft-lbs torque, at wide angles, and also ~2″ of length changes.


OEM Corvette axles, with the inner CVs taken apart…after 99.9% of the mess has been cleaned up

Install & full suspension sweep: Installing is easy…key was to get the axles to be fully seated onto the uprights to ensure I had the correct effective axle length between the upright and tranny. i then removed the rear suspension, and used a jack to simulate 1) full droop (plus margin) to ensure the axle was long enough, then 2) full compression (or where the spindle is at the same level as the tranny…the shortest distance for the axle) to ensure the axle is short enough that it wont bottom out and push into the tranny.

Using a jack to swing the suspension through full droop to full compression to ensure no binding.
Bolted into place…this was at the minimum distance (axle level with tranny), you can see the inner CV isn’t inserted too far into the outer CV; when the suspension is at full droop, the inner pulls out and was marginal…thus I added a spacer.

Adding a Spacer: the axle was marginal to full droop…and I wanted to have additional droop capability in case I ever needed more, and since I had lots of room under full compression, I added small spacer. A few Porsche specific shops sold spacers for $600, but I found a set from a dune buggy shop for $80 that included the longer bolts included!

trial fitting difference spacer widths to figure out what was needed before ordering.
testing full droop
the new spacer…nice piece with lips that fit perfectly.

final install: Once everything was checked out, I slide on the CV boot, installed the axles, and then filled with grease. I’ve yet to find an easy/clean way to do this. I then installed the boot and tried my new boot clip tool to tighten OEM-style clamps…those clamps ended up being over-tighten and cracked, so I resorted to worm-gear style clamps which get the job done. I then rotated the wheels to listen for any odd sounds.

final install w/ spacer