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6-speed Transaxle Upgrade Kit For The Porsche® 928

Application: 1978-95 Porsche® 928 with Manual Transmission

Description: A bolt in replacement transaxle kit for the Porsche® 928, replacing the expensive and hard-to-find Porsche® 928 5-speed with the stronger and less expensive T56 trans from the Chevrolet Corvette. The transaxle can be installed stock or upgraded, and parts are plentiful. With readily-available upgrades to the Chevrolet transaxle, the transaxle can be made to hold 1000 lb ft of Torque.

At this time, we are only using the 2001-2004 C5 ZO6 manual transaxle with this kit. In the future, we may be able to use the standard 1997-2004 Corvette C5 (non-ZO6) and the later C6 transaxles and torque tubes.

The Porsche® 928 independent rear suspension and brakes are maintained, so you will not loose any performance nor your investment in 928 brake and suspension upgrades. You will still use them.

The Porsche® 928 clutch and flywheel is also maintained, so you will still be able to service your clutch without removing the engine or transmission. The 928 Motorsports aluminum flywheels and performance clutch packages are compatible.

Kit includes:
  • Modification of your Corvette aluminum torque tube
  • 928MS custom forward driveshaft section
  • Performance driveshaft couplers
  • 928MS custom half-shafts
  • 928MS trans-axle support with mounts
  • 928MS custom shifter mount and shift rail
  • Installation instructions

Automatic-to-Manual Conversions: This kit can also be used to convert a 928 with automatic transaxle into a manual trans car. One of the largest expenses of such a swap has always been finding and acquiring a good used Porsche 928 transaxle. You also need the 928 torque tube, flywheel, clutch assembly, bell housing, and pedal assembly. Good used Corvette 6-speed transaxles are much more plentiful and less expensive (and more fun!). With the parts we supply in this kit, the actual 928 items you need to buy to finish the swap is limited to only the clutch and clutch pedal systems.

I have designed the kit to use for either polyurethane mounts for street-driven cars without roll cages , and solid mounts for racers and cars with roll cages.

Rather than make our own cross-member - we were concerned that it would be hard to locate each suspension point and angle of the Weissach rear end correctly - so I have opted to buy stock rear cross-members from 928 Intl and modify them. Then I know without question that all the suspension mounting points and angles are correct. There will be no alignment issues this way.

Each cross-member gets cleaned and bead-blasted, sectioned, then milled in a jig we have made to square it up to the transaxle.
From there we will be installing steel threaded inserts into the ends, but first we have the webbing in that area completely filled with aluminum by a professional welder. Then the full-circle threaded inserts are installed.

In addition to these two bolts on each side of the cross-member, we made our mount reach around and capture the factory cross-member-to-body mount as well. So we have 3 bolts on a side, two M14 fasteners into the cross-member and a M12 into the body.

The center section of our cross-member is made from mandrel bent 4130 Chrome Moly tubing. It is stronger than the aluminum section we removed.

Two ways to install: We can ship the kit to you so you or your mechanics can install it. Or, you can send your 928 to us and we will install the 6-speed transaxle and kit for you. When the installation is finished, customers usually fly in to Milwaukee airport and we pick them up there in their own car and they drive it home. Call for pricing if you are having us do the installation.

We offer our customers the option to have their rear cross-member made without parking brake mounts (lighter for the racers) or with parking brake mounts (better for the street-driven cars)

What to send us: Whether we are installing it or you are, you still need to send us some of your Corvette parts so we can modify them. You need to supply us with your:

  • C5 ZO6 Corvette Torque Tube
  • C5 ZO6 Corvette driveshaft
  • C5 ZO6 Corvette shifter mount
  • C5 ZO6 Corvette shifter linkage

Each of these items will be modified by us and returned to you for use in your 928.

If we are installing the 6-speed for you, you also need to supply us with your C5 Z06 transaxle with differential.

Please note that all these pictures are of raw, unpainted parts. The finished parts the customer receives will be powder-coated.






6-speed Transaxle Upgrade Kit For The Porsche® 928



Call for availability

* Domestic US shipping shown. International shipping will be calculated based on location.


Phone: (920) 485-0928
Email: info@928motorsports.com

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Horicon, Wisconsin USA

928Motorsports.com - Performance Parts for your Porsche® 928