jfh75-911S

I have just acquired a rebuilt 915/63 transmission which I think was the standard five speed in the 1978 all of U.S. 911S and I'd love to use it in my 1975 911S. What I'd like to know is what would be involved in swapping the 915/63 for my 915/40 tranny? I know the 1978 doesn't have the connection for a mechanical speedometer like I have, but I don't know what's involved in changing to an electrical one. Also are there any differences in the way the clutch works between the '78 and ' 75 models?

Jack

Steve Weiner-Rennsport Systems

Hi Jack:

These trannies are otherwise identical so when we do these conversions, I simply buy a good used electronic speedo and make the substitution.

You will need a '78 style clutch cable, too.

Thats it.

jfh75-911S

Thanks for the info Steve. Is there a web site or article some place that would give me more details for making this swap. For instance, I don't even know where the speedo should attach.

Jack

Peter Zimmermann

Steve: Can you buy a factory speedo harness, or do you make one?

Jack: Your SC trans may, or may not have, come with the throwout bearing release mechanism used in '77 - 86 cars. If it didn't you might start looking for the parts. It's highly recommended, as Steve mentioned, to upgrade the clutch release system/cable. Be careful to not buy an aftermarket cable! They're out there, look identical to o.e., but they say "Made in West Germany" on the black bowden tube part of the cable. Yes, that's right, the aftermarket cable has the writing. For some reason a few months/few thousand miles after installation the aftermarket cable tightens up, which increases the pedal pressure required to depress the clutch. Very uncomfortable.
Pete