Gavin Still

Folks,

I know people have talked a lot about certain aspects of the 915 transmission, but I wanted a bit more general opinion...not about whether it's a good transmission or not, but...

A week ago I drove a 1979 SC that I plan to buy. I have always driven manual transmission cars, including a 996 I used to own, but this was my first time driving an air-cooled car. To be honest, I found the 915 transmission a bit of effort to shift.

I expected it to be a bit "loose" as this is a 40 year old car with quite a few miles on it. It was actually quite "tight" and no matter how I played with shifting vs revs on my 20 minute drive, it took a bit of pressure to get into the gears -- say two fingers worth. Not forcing, that's for sure, and felt like I was shifting where the car wanted to shift as I was able to shift smoothly from a speed standpoint, but the feel wasn't buttery at all.

As additional info, the clutch disengaged very early in the range of the pedal's motion, so certainly no clutch cable issues.

The seller (reputable Porsche-specialist shop) did tell me that the transmission was recently rebuilt and some aftermarket gating system (perhaps Seine? -- I need to find out) was installed.

To be clear, no problems shifting at all -- just more effort and less "buttery" than I expected.

Fully willing to admit that in 20 minutes I wouldn't become familiar with a car, and that it is of course an old style transmission.

Thoughts?

The Greek

It might be that the shift coupler needs some little adjusting. Located behind the seats.

But yes, I have a love hate relationship with the 915. G50 just shifts miles better, but I do love the vintage aspect of it and how you have to respect it.

theiceman

yeah its certainly not ' buttery" or anything like that. Sounds about right. its a old classic gearbox. i have a modern 6spd that is almost zero effort to change and i tell you i love the feel of my 915 when i get in it. feels like a mans car

pu911rsr

Freshly rebuilt 915's will require some effort to change gears- sounds about right to me.

Phil

Gavin Still

Thank you -- I want the car since I love Porsches and I want the vintage feel so I suppose the 915 is part of all of that

fenixv8

I drove three 915 transmission cars before I bought my 72T and they were all really sloppy. When I purchased my 72T it felt completely different that those other 3 cars, tight and nice. Didnt require too much effort to shift and was precise not vague like the other tired cars I drove before.

I find that my 72 915 tranny requires less effort to shift than my 1990 964 G50 tranny. But the G50 was tighter overall. Not sure if my G50 was just old and not maintained but i prefer my 915. Both 915 and G50 had new bushings and parts.

r911

slow butter maybe - if in good shape, and if the 3 shifter bushings are in good shape, AND with the coupler correctly adjusted... the driver needs to move the lever to the right spot and put very, very gently pressure onit, while taking a moment to savor the experience, as it goes into gear...

it is like a fine Burgundy wine, not a Bordeaux

and you cannot beat the synchros

Dave Inc.

Yes with the 915 in good condition it still feels like you need to knock on the synchro's door and ask for permission to come in. Good luck with the purchase, hope it works out for you!

wareaglescott

This is a great question. I struggle to know how it should shift. Drove 3 SC's prior to buying mine and they all were similar. It certainly is different. I have no idea what a new or freshly rebuilt one would be like but I sort of figured since all 3 were similar that is just how they were!

gt-2

I'm not a 915 expert but I have many cars with 915s and in my experience adjusting the shift coupler properly is a big (but not only) key to properly shifting 915. First gear is always a marginally tougher gear to engage (especially with a short shift kit) but all others should require reasonable effort and shouldn't be too difficult but just slightly more confident shift into position. It will never be a G50 but I don't mind the effort of a 915. Most of the time you can tell a coupler is out of adjustment because you'll find it tough not to grind slightly on downshifts especially from 5th to 4th, and sometimes reverse is hard to "find". Adjusting coupler can make shifting much better if done correctly assuming the 915 was rebuilt properly to begin with.

Spyerx

Try driving a 901!!!
Sounds about right. A bit floppy. But. They work well

oldskewel

Some general comments ...
- the 915 in my '85 shifts just fine. Smooth, no problems other than going into first, which just requires a little finesse.
- in general with shifting difficulty on rear engine cars, I'd expect tuning up of the shift linkage to have a huge positive impact. So if it's new and stiff / difficult, maybe you need to wear it in a little, and then adjust things. But ...
- I've read more than a few stories, including on this site, where a rebuilt transmission ends up failing not too far down the road. Sometimes repeatedly. Given that, at least I would not consider the newly rebuilt 915 to greatly enhance the value vs. a good-running original 915.

Gavin Still

Thanks for all the honest well thought out responses. Really helps me out.

Gavin Still

lol that’s a great analogy it felt like knocking on the synchros door.

dr914

the 915 is baulky heavy with a heavy feeling clutch (even with a good helper spring!). You are spoiled driving a late model car, the earlier ones (especially the 74-86) are barbaric. With good coupler, ball cup, and shift rod bushings, it is about as good as it will get, buy actually installing the factory short shift makes it a bit better. Very important to have the clutch cable well lubricated and adjusted correctly and make sure that the two helper springs are not broken. The 901 is a joy and the g50 is great. Maybe try to find a 87-89 model instead. Besides the g50 with hydraulic clutch, you get Motronic fuel injection which is less troublesome than the old CIS