I stopped in Lake Havasu this week to check out California Motorsports.net This business is exclusively focused on Porsche transaxle rebuilding and upgrading. Current projects in work included; (2) 993 twin turbo boxes, 2 G50 boxes and a few 901 rebuilds. they have recently completed 4 Ruf gearboxes, apparently there is a lot of custom gears and shafts in the box that other shops won't touch.

https://californiamotorsports.net/

These guys are pounding a staggering output of Porsche only gearboxes out of a 3k sqr ft facility in a small industrial park.

I met with Shaun Hart who does all the disassembly and reassembly. His father does the machining. Maybe two more guys in the shop. The make a number of gearbox parts but are most well known for their stiffer billet Diff side plates that keep the ring from separating from the pinion under high loads.
Their shop is spotlessly clean
Shaun keeps all trans and case parts together and never co-mingles parts with other projects in the shop
They photo documents teardown and damaged parts
Then media blasts, then tumble deburrs all cast parts See attached example casting surface ready for reassembly
They bench tests all final assembled trans for noise and perf. issues (up to 1500 rpm)
Shaun has has an immense knowledge of the Porsche vs. Borg Warner designs and specifically the dog and synchro parts and with early 928 gearbox issues
Their basic labor cost for a 928 transaxle is $1095 plus parts.
I dropped off the LSD I purchased from Mark. He will complete the teardown and report in two weeks. If it needs all new clutches, it about $500 for the LSD.


There will be an updated post when the gearbox arrives and gets torn down.

 

This'll be interesting!

 

The transaxle from 001117 got dropped off at CMS in Lake Havasu last week. Today Shaun sent me the first images at teardown. Odometer at 54k is starting to match the physical (wear) evidence on the internals. A separate early Limited Slip Differential was provided for rebuild and reassembly.







ages of the transaxle at teardown. The condition of the casting internal surfaces and gearsets are at teardown, i.e. before we start the rebuild. So far it appears to be syncros on 1, 2 and 5th. More to follow. Images below.

 

This will be cool to watch

 

This is cheaper and easier than taking it up the street and have Greg Brown rebuild it?

 

It is not about the ease or the expense. It's about specialization. All CMS does is rebuild Porsche transaxles. All day. Everyday.
All transaxles require very specialized tooling, instrumentation and extremely focused expertise to reassemble correctly. CMS has all of this and a proprietary in house ability to tumble / deburr the case, the ability to dynamically load the box and test it before shipment. Their lead time is 3 weeks.

 

PM Sent.

 

Great to see the care and passion you have demonstrated for your other projects being directed to your first 928! Took some time for the 928 bug your brother had so many years to finally flower. Joe's 928 was always a wonder to see.
Welcome to the 928 family (officially now!) and looking forward to following the journey with this early car. Thrilled to have you aboard!
Best,
William