bnen911

Hello, I am wondering about the 915 tranny in my car. I replaced the bushings, fluid, adjusted it as best I can but I am still having a common issue I would say. It shifts into 2nd when it's good and ready, 75% of the time, all other gears are fine.

What is your opinion on shifters? Or rebuild kits for the shifter? Short shifters? Lets just say anything short of a rebuilding the transmission.

Love to hears your thoughts.

Cheers.

GTgears

At what rpm do you make your 1-2 shift?

bnen911

I guess it depends on how I feel. I would say that if I get it around 5000 and I go to 2nd it's a bit of a pull, just at the last inch of the shift, but not every time. Warm engine and trann's helps too.

GTgears

OK. You are in the right ball park. The most common issue I see is shifting too early into 2nd. Anything below about 4000rpm and the synchros actually have to speed up the gear to get it to engage. The other thing is that 2nd is what many of us call a 2 stage shift. It's subtle, and you need to start the shift to the point of making the slider grab the synchro, and then you give it almost 1 Mississippi before you click it fully into gear. It will NEVER be a quick shift. A 915 is best driven in the 2-3-4 range. 5th is for cruising and 1st is for getting off the line. As long is the car is rolling, you never need to shift down into 1st, and you really shouldn't ever engage 1st unless at a stop.

What are you running for gear oil? You want a mineral based oil in there. Swepco and Kendall are the two that are argued about a lot. But Redline, Mobil, Motul. Any of the synthetics will be too slippery. If you have synth oil in there get it out.

bnen911

Hello and thanks for the info,that helps things and explains what has become second nature, for the most part .. time with the car has been great.

I am using Fuchs tranny oil, that is what a good shop near me uses, what do you think?

GTgears

Never even heard of Fuchs tranny oil, and I manufacture gearbox parts for a living. Are you overseas? Not something I've seen here in the States.

oldskewel

Sounds like great advice - matches with my experience with my '85 (early).

I did not exactly understand your advice regarding gear oil. I've been using SWEPCO for almost 20 years now. Are you agreeing that that is the way to go, along with Kendall, but that Redline, Mobil 1, Motul, and any other synthetics are not recommended?

I've got no complaints with my SWEPCO at ~130k miles, but have not personally compared it to anything else.

GTgears

Yep. Stick to Swepco or Kendall and you will do fine. I stay out of the debate regarding which one is "better".

JCP911S

Back in the day, newbie owners tried to speed-shift the 1-2 shift, and that wears out the 2nd synchro pretty quickly... so a PO did that, you're kind of stuck with it...

To avoid a re-build, you can nurse a balky 2nd gear synchro... my '84 3.2 is torquey enough that it can be driven in 2nd gear at almost any speed, and in fact can easily be started from a dead stop (although this does put some extra load on the clutch).

Actually, I find my car likes to be shifted into 2nd at about 2,000RPM... as pointed out, this is a very gentle shift with a pause in neutral.... I only use 1st for parking, and getting the car rolling from a dead stop.... the gearbox will tell you what it likes.

bnen911

Hello, I bought the oil from Mantis Automtive in Oakville On. Canada. I doubt it's the lub I am using but will try something different next time.

Also when you say po does that mean previous owner ?

Thanks for the input by the way. I am getting a new clutch and some oil leak issues fixed next week so with all that sorted I may notice a bit of an improvement too.

CheeRS.

pooshee

Longtime lurker, first time poster...
In my experience(a-hem) with manual gear boxes (not a transmission specialist, but have driven Manuel since age 10, including fiats, old 2002s, vw buses, karma ghia, 911, 993, 991 pdk with and without turbo, tiptronic, Mercedes manuels, 3 speed, 4 speed automatics, just a normal dude enjoying weekend afternoons in cool old cars of various varieties, and appreciating how they were made in their period...) I can say the 915 is a great transmission but not "crisp" to shift even in its best state , especially into second. The cars have been around enough to have 2 gear synchro worn out. Either get it fixed and enjoy a better shift and less gringing still slow into second or nurse that 2nd gear shift and know it's gonna be slow and purposeful shift evertime. But the 915 is only a bit more "crisp" then shifing a gear box from a vw...it works, it's good, but almost loose and sloppy, like fishing with your hand for marbels in a velvet bag.

Basically my point is, that's how it shifts...enjoy it. This is also why you don't let people drive your 915 gearbox unless they know how to "find the gear" properly.

I have swepco I t here now...gonna change to Kendal

bnen911

I hear what everyone is saying and understand totally. Just looking for opinion's. The bushing helped a lot, I am just wondering about all this. I am in love with everything about my car.

I guess no one has a shifter installed, like a WEVO, or a short shift kit to talk about? I have a feeling money could be spent on better things.

Thanks..

Scott997

I have a Rennshift and love it. Takes the 915 to the next level. Self Centering, very positive feel. In my opinion it is a must do mod.

j.kenzie@sbcglobal.net

+1
Huge improvement for me as well. When I removed my old factory short shift, it was very sloppy. The Rennshift is precision.
Good luck,
Dave

theiceman

I'd say forget the shifters.
I would say going into 2ns when it's good and ready is somewhat normal for a 915 and a shifter will not help this
Speed shifting into second before it's ready will shorten the life of that synchro significantly.
I would say it is normal to have a " pregnant pause" between first and second.
Of course if you find it is longer than other 915s, it is likely it is second gear synchro time. Usually first and second are done together with dog teeth and bands.
If you are not doing it yourself it may be time for an overhaul , depending on what you can live with.
I've had a marginal second gear synchro for 9 years.