915 Transmission Rebuild

[72911targa]

New to the Porsche rebuilding world and am working on a 72 911 with a non matching fresh 2.4 E motor.

After taking the trans apart and I'm no gear guy, reverse is missing a few teeth. The rest look good but a little shinny. Once again I should stay in my own lane on this.

Contacted G-Box and Cog's. After doing some research I cannot find anything of recent reporting to help with their ratings. It's mechanical so you can't make everyone happy.

Anyone have recent dealings with either? Know of anyone else I should be talking to on the west coast? I live in Reno.

Someone pitched me a 77 915 that had been rebuild. I release that I would have to change the speedo and run some wires. Is there any advantage to newer 915? Running the 2.4 with MFI will it require anything else to convert that I'm not aware of?

Seems like I'm always that guy that only gets half the story right.

Thanks for your input.

[Sboxin]

Originally Posted by 72911targa

New to the Porsche rebuilding world and am working on a 72 911 with a non matching fresh 2.4 E motor.

After taking the trans apart and I'm no gear guy, reverse is missing a few teeth. The rest look good but a little shinny. Once again I should stay in my own lane on this.

Contacted G-Box and Cog's. After doing some research I cannot find anything of recent reporting to help with their ratings. It's mechanical so you can't make everyone happy.

Anyone have recent dealings with either? Know of anyone else I should be talking to on the west coast? I live in Reno.

Someone pitched me a 77 915 that had been rebuild. I release that I would have to change the speedo and run some wires. Is there any advantage to newer 915? Running the 2.4 with MFI will it require anything else to convert that I'm not aware of?

Seems like I'm always that guy that only gets half the story right.

Thanks for your input.

You might want to talk to the guys at EBS Racing in Reno . . . I have bought parts from them (recently 964 crankshaft) and had cylinders machined and replated.
https://www.ebsracing.com/

Also, on the West coast call and talk to Roger at CMS . . . they build our 915 racing transmission https://californiamotorsports.net/products/cms-915-transmission-rebuild

CMS is not cheep but they do an expert rebuild to like new condition transmission . . .

Wish you the best on your project,
Regards,
Roy T

PS: Our fist 911 was a 1972 911T coupe with mechanical fuel injection

[HarryD]

If it was me, I would keep the 1972 box with the 7:31 ring and pinion vs the later one which is taller.

This web site may be helpful: Porsche Wiki

Also, there is extensive discussion here on 915 rebuilding. A few hours of searching/reading may be helpful.

[flat6pilot]

I wouldn't recommend either G-Box or Cogs.

+1 on CMS on the Westcoast. https://californiamotorsports.net/ They're actually in Arizona now.

[Matt Monson]

Originally Posted by flat6pilot

I wouldn't recommend either G-Box or Cogs.

+1 on CMS on the Westcoast. https://californiamotorsports.net/

This.

[winders]

The best guy out there is Bill Rader at Bill Rader Motorsports. Period!

[-Levi-]

Another vote for CMS.

[shoooo32]

If you've gotten this far, I'd keep going. Between the Bentley manual and the aforementioned wiki, it's pretty straightforward. If the pinion bearing race has spun you'll want to reach out to CMS anyway. Roger at CMS is great to work with.