Thanks to Brian Wolff for the following information on tranaxles:

The first one is called an R25 or UN1 transmission and they were originally put into the 1987-1989 series Eagle Medallions (AMC/Chrysler/Jeep)! Although a little smaller than the ZF they can take up to 400 hp. The Brits and Aussies have been using them for years both for street and racing.

 



The other transmission that you might consider is the Hewland racing transmission. They go for about $2000 and as far as I can tell they do every the ZF does but at a fraction of the cost.

And, last but not least, there is also a transmission from a lesser known Audi that is also a match but I still have to get some more info on it. However, my feeling on this one is that it won't be as available as the R25 in North America.

Renault transaxle Data

Renault five speed manual transaxle gear and differential ratios

Model

Part No.

1st

2nd

3rd

4th

5th

Rev

Diff

20

369.00

3.36

2.06

1.38

1.06

0.82

3.55

4.11

 

369.05

3.36

2.06

1.38

1.06

0.82

3.55

4.11

20TX

369

3.36

2.06

1.38

1.06

0.87

3.55

3.778

20LS/TS

369

3.82

2.18

1.41

1.03

0.86

3.55

3.778

21Turbo

UN1-013

3.36

2.05

1.38

1.03

0.82

3.54

3.44

25GTX

UN 1-03

3.36

2.05

1.38

1.04

0.82

3.55

3.89

25V6

UN 1-04

3.36

2.05

1.38

0.96

0.76

3.55

3.89

Alpine GTA

UN1-05

3.36

2.05

1.38

1.04

0.82

3.55

3.44

25 Blindee

UN 1-06

3.36

2.05

1.38

0.96

0.76

3.55

4.11

Alpine Turbo

UN1-07

3.36

2.05

1.38

0.96

0.76

3.55

3.44

25V6 Turbo

UN1-08

3.36

2.05

1.38

0.96

0.76

3.55

3.778

30TX

369-01/06/017

3.36

2.05

1.38

1.06

0.82

3.55

3.89

30TS

369-01/06/014

3.36

2.05

1.38

1.06

0.82

3.55

3.89

The type UN1-013 Renault 21 Turbo is the preferred transaxle for use in the GT40 replicas although the 25 Turbo and GTA boxes are also often used. Also note that if the GTA box is used it either has to be inverted or the differential reversed unless five reverse gears are required. On all boxes the selector shaft has to be modified to extend out of the right hand side of the gearbox so as to link up with the right hand gear change linkage. The preferred CV joints are from the Ford Granada and adaptors have to be fitted to the Renault transaxle output shafts to couple to these. These adaptors are commercially available items.

The transaxle type can be found on a small aluminum disk around 1-1/4" diameter which is held onto the box by one of the fixing bolts on the rear end cover of the gearbox. Unfortunately if this cover has ever been removed the disk is rarely replaced and the only way to identify the box is by checking the gear ratios.

Audi transaxle Data

 Audi 100/200/9000 five speed manual transaxle gear and differential ratios

Type

1st

2nd

3rd

4th

5th

Rev

Diff

Speedo drive

013 Serial Number prefix 3T

3.46

1.79

1.07

0.78

0.60

3.17

4.11

0.52

013 Serial Number prefix HE

3.46

1.79

1.13

0.83

0.68

3.17

4.11

0.52

013 Serial Number prefix HF

3.46

1.79

1.13

0.83

0.68

3.17

4.11

0.52

093 Serial Number prefix 3Q

2.84

1.52

0.90

0.64

0.48

3.16

5.22

0.52

016 Serial Number prefix AAZ

3.60

2.13

1.46

1.07

0.86

3.50

3.89

0.52

016 Serial Number prefix 3V

3.60

2.13

1.46

1.07

0.83

3.50

3.89

0.52

016 Serial Number prefix 3K

3.60

2.13

1.36

0.97

0.78

3.50

3.89

0.52

016 Serial Number prefix 5N

3.60

2.13

1.36

0.97

0.73

3.50

4.11

0.52

016 Serial Number prefix 3U

3.60

1.88

1.19

0.84

0.64

3.50

3.89

0.52

016 Serial Number prefix BMO

3.60

1.94

1.23

0.903

0.684

3.50

3.89

0.52

Audi 100/200/9000 four speed manual transaxle gear and differential ratios

Type

1st

2nd

3rd

4th

Rev

Diff

Speedo drive

014 Serial Number prefix QN

3.46

1.79

1.07

0.70

3.17

4.11

0.52

014 Serial Number prefix 4X

3.46

1.79

1.07

0.70

3.17

4.11

0.52

The Audi suffix 016 transaxle is the preferred transaxle for use in the GT40 replicas. The 016 boxes have the selector shaft on the left hand side, all other boxes have the shaft in line out of the back of the box. The 016 selector shaft has to be modified to extend out of the right hand side of the gearbox so as to link up with the right hand gear change linkage. The CV joints used on most (UK) GT40 replicas are from the Ford Granada and the output shafts on the Audi type 013 transaxle have mountings to suit. The Audi type 016 has output flanges to suit similar but slightly larger diameter CV joints which could be adapted for use with the smaller CV's if necessary or better still to use as standard with larger diameter drive shafts. Note that Audi 200 were later versions of this car and the 9000 range were again the same but the American version of the car.

The standard Ford V6 flywheel commonly used on GT40 replicas will not fit into the bell housing on this transaxle. A special flywheel or extra thick adaptor plate will have to be used. The standard Audi flywheel would have too many fixing holes making the mounting unsafe if modified for use with the Ford V8.

Brian's message references a Hewland racing trans -- not sure which, as there's no model number, but in that price range I'm guessing the mk8/9 or newer LD 200. Just so your readers know, it's well-known in SCCA formula racing circles that the mk8/9 *will* fail around 160 ft-lbs -- lower with older gears! It may handle 400hp, but not below 13,130 RPM. ;-) The LD-200 is rated by Hewland at 160 ft-lbs, though I don't have personal experience here. On the plus side, there are dozens of user-changeable gear sets and many repair parts available for both, so they are a great choice for lower power applications.  - Pat