What CWP Ratio on the 915/40

[crashr]

Hi Folks,

Just trying to figure out what gearing ratio is on my transmission. I have done a bunch of searches and read the "What is the best 915 transmission" thread, however after all that I am still a bit confused as to what gear ratio I have.

The stamping on the bottom of the transmission looks to be:

915/40 715 2449

From what I gather this is a five speed manual fitted to RoW 911S, U.S. 911S, and US Carrera, during 1975.

From what I read though it appears that the change from 7:31 to 8:31 happened sometime during 1975. How can I tell then which I have?

I was looking into this because a mechanic I was talking to not to long ago mentioned that I should be careful with my 3.2 Euro engine if it is a 7:31 transmission, for fear of damaging the gears. Any comments?

Thanks,

[Bill Verburg]

Originally Posted by crashr

Hi Folks,

Just trying to figure out what gearing ratio is on my transmission. I have done a bunch of searches and read the "What is the best 915 transmission" thread, however after all that I am still a bit confused as to what gear ratio I have.

The stamping on the bottom of the transmission looks to be:

915/40 715 2449

From what I gather this is a five speed manual fitted to RoW 911S, U.S. 911S, and US Carrera, during 1975.

From what I read though it appears that the change from 7:31 to 8:31 happened sometime during 1975. How can I tell then which I have?

I was looking into this because a mechanic I was talking to not to long ago mentioned that I should be careful with my 3.2 Euro engine if it is a 7:31 transmission, for fear of damaging the gears. Any comments?

Thanks,

8:31cwp
& here's the rest
35 33 29 26 23
11 18 23 26 28

[crashr]

Thanks Bill.

So I guess I don't have to worry quite as much about the torque from the 3.2 on the transmission.