ZF/RBT Transaxles

06-03-02, 02:22 PM

Welcome Lloyd! I think you will find dropping in here from time to time an enjoyable experience. We have a wide range of characters, craftsman, enthusiasts all of whom love GT40s and anything automotive. Since you are the present owner of one of the major components found in many of our objects of affection, your comments and insights will be GREATLY appreciated.

Can you tell us about any updates RBT has made to the original design of the 5DS-25-x. For instance: changes in synchro design or materials, changes to increase torque ratings, etc. Again, thanks for stopping by.

Regards,

LButfoy · 06-04-02, 01:10 AM

Hello, I was ask to come on board to give any info on the ZF 5speeds/RBT6-speeds as we are the builders and supply OEM parts for the ZF 5DS25/0/1/2 and M1 Transaxles you can e-mail me or call (714)516-1215
Owner:RBT Transmissions Lloyd Butfoy www.rbttrans.com

LButfoy · 06-04-02, 02:32 AM

The ZF box is still the strongest transaxle for it's size on the market, We had to redesign all the internals in the RBT-6speed,we added a two inch spacer to the 5-speed case to accept the extra gear, we have all new duel cone synchros and all the gears are 9310 steel and finnish ground. We still supply and build the ZF DS25 boxes. We build the GT-40 ZF 5-speed, we have the lids with the mounting ears and breather. I do have rebuilt ZF's on a limited bases. Lloyd

06-04-02, 12:12 PM

Thanks for the info Lloyd. I priced a ZF back in 1972 when a De Tomaso was selling for $10K and the dealership in Chicago wanted $5K for a 5DS25. The transaxle has always been the issue if you wanted to build a midengine car in the US since the beginning. There are some ERA builders here and John Hester, GT Supercars, is going to offer his chassis with optional pickup points for ZF, Porsche and Audi, so there are plenty of people who will benefit.

GT40 MKII · 06-17-02, 03:17 AM

Lloyd, what is the power limit of your 6 speed. Also, can you get other final drive ratios?

LButfoy · 06-18-02, 05:37 PM

We have 5,37 4,22 3,7 and 3,2 ring and pinions with .705 .655 .642 6th gears
Saleen and Shelby are running 450+hp and torque with no problem.