915 transaxle question / info, a silly question... Options

[CCSmith58]

Hello 914world… Just renewed my Membership !! Now looking to get my moneys worth...

I’m having a ’75 914 built into a 914-6.
Maybe 10 or 20 years ago I might have tried to do (some of) it myself.
Now I’m more a “pay the money, turn the key” guy.
Here’s a “silly” question. Likely the first of many….
How does a 915 Transaxle work when converted to a mid engine application ??
Not looking for a “how to” just an overview for personal info.
I’ve searched for articles, webpages and / or videos and don't find much.
I find acknowledgements of the conversion but no detailed or even general description.
I see the term “flipped ring and pinion”.
Does the whole gear system run backwards ??
Does just the differential run backwards ??
How would a LSD work in a converted 915 ??
Are the available 916 Kits good ??
Etc...
Any info or links to info would be appreciated !!

[JWest]

Shifter information: all 915 conversions that have ever been made use a 911/tail-shift style shifter with the ball cup and support bracket under the shifter.

Some 915 conversions are referred to as "side-shift" but the linkage is not designed to use the 914 side-shift type shifter. If you use the side-shift shifter with a 915, you will end up with the shift pattern flipped left-to-right.

[rgalla9146]

Shifter information: all 915 conversions that have ever been made use a 911/tail-shift style shifter with the ball cup and support bracket under the shifter.

Some 915 conversions are referred to as "side-shift" but the linkage is not designed to use the 914 side-shift type shifter. If you use the side-shift shifter with a 915, you will end up with the shift pattern flipped left-to-right.

(IMG:style_emoticons/default/agree.gif) The only experience I have with a 916 is my own but I realized early on
that the reverse interlock on a 914 side shifter and the change of motion would
not work with a 915.
My trans is a '72. It's the only 915 that uses a stamped steel shift base that looks
just like a 914 rear shifter.......but it is very different down below.
The reverse lockout is on the opposite side and has two additional small springs.
I was lucky to find one.
I think the '73 and on 911 aluminum bases are the correct choice for any
915/916 install. OR, your choice of quality aftermarket 915 replacements.
Rory

[Steve]

Shifter information: all 915 conversions that have ever been made use a 911/tail-shift style shifter with the ball cup and support bracket under the shifter.

Some 915 conversions are referred to as "side-shift" but the linkage is not designed to use the 914 side-shift type shifter. If you use the side-shift shifter with a 915, you will end up with the shift pattern flipped left-to-right.

(IMG:style_emoticons/default/agree.gif) The only experience I have with a 916 is my own but I realized early on
that the reverse interlock on a 914 side shifter and the change of motion would
not work with a 915.
My trans is a '72. It's the only 915 that uses a stamped steel shift base that looks
just like a 914 rear shifter.......but it is very different down below.
The reverse lockout is on the opposite side and has two additional small springs.
I was lucky to find one.
I think the '73 and on 911 aluminum bases are the correct choice for any
915/916 install. OR, your choice of quality aftermarket 915 replacements.
Rory

I tried them all desperately trying to figure out why it wouldn’t shift right before taking the car to Patrick Motorsports. The 916’s and other period correct GT’s with a 915 gearbox all have this one year 1972 shifter, since that is the year they came out. It looks like a 901 shifter with the reverse lockout on the other side. I still have one in my collection. I sold the Wevo and kept the 915 rennshift that JWest mentioned. The 915 rennshift is much more precise and with the stock short throw, I have zero issues with the 5th reverse lockout. The rennshift and Wevo is spring loaded to the 3rd and 4th gate, but the Rennshift also has a shorter left and right neutral. Literally when shifting from 2nd to 3rd all I do is push up on the Rennshift and it automatically goes into 3rd like butter. The stock 915 shifter and one off 1972 915 shifter is only spring loaded for reverse and 5th. The rest of the gears you have to fish for.
Notice goofy one off part numbers 18,19 and 20 5th reverse lockout. It does work and is period correct, but doesn’t shift like a modern Rennshift.