Robb 79SC

I am a first time Porsche owner - a 79SC with 140k miles. Runs beautifully but about half the time I up-shift from first to second I have a very difficult time engaging second. No grinding, just hard to pull into gear. Downshifts are no problem and neither are any of the other gears. Any ideas on the cause or what I need to do? Thanks for the help.

Robb

Bill Gregory

Robb,

If misery loves company, I was having a similar condition on my 81SC with 120K miles. No grinding, but almost like a thud or kathunk to pull it into 2nd. I lived with it, as I believe a rebuild may be the ultimate fix.

Robb 79SC

Bill,

Thanks for the reply. I was hoping this was as simple as replacing some bushing. I think I will take your approach and just live with it until rebuild time.

nate

Try keeping the RPMs up around 2000-2500 RPM when up shifting. I found that this makes the shifts go a little more smoothly and a little faster. You'll probably have to play with the engine speed relative to car speed.

Bill Gregory

[quote]<strong>I was hoping this was as simple as replacing some bushing. </strong><hr></blockquote>

When I put in the factory short shift kit, I also replaced the bushings in the shift linkage outside the transmission, and, while tightening things up, it didn't improve the 1st to 2nd thunk.

Steve Weiner-Rennsport Systems

[quote]Originally posted by Robb 79SC:
<strong>I am a first time Porsche owner - a 79SC with 140k miles. Runs beautifully but about half the time I up-shift from first to second I have a very difficult time engaging second. No grinding, just hard to pull into gear. Downshifts are no problem and neither are any of the other gears. Any ideas on the cause or what I need to do? Thanks for the help.

Robb</strong><hr></blockquote>

Hi Robb:

It does sound like a typical high-mileage 915 transmission but I'd sure suggest that you use Swepco # 201 gear oil in that, if you do not know precisely what is in there.

Thta really does help the shift quality in these gearboxes and they will last a very long time if you are patient with each shift.

Ted Ritter

Robb,
Exact same thing on my 86; until yesterday. Factory short shift kit with new bushings. Much better now. Don't quite agree with Nate on low RPM shifting. P engines love a healthy dose of revs to stay happy & healthy.
Ted
86 Carrera T Blk/Blk <img src="graemlins/yltype.gif" border="0" alt="[typing]" />

Perkins

Echoing what Steve said above...
Replace your transmission oil with Swepco 201.
this could make a world of difference.

good luck,
Maurice
1980 SC Coupe

Drew Theodore

Does anybody with a 1979 to 1983 911SC not have this problem? This topic is brought up every so often and there are always a lot of replys saying have the same problem. I have the same problem and the 2 911SC I test drove before buying mine also was hard to shift from 1st to 2nd.

eurocarrera

This is just a common occurance with these transmissions. As a matter of fact, I can't think of anyone who really hasn't had some problems with the 915 tranny after 10 or 15 years. My trans was actually rebuilt two years ago, and I still have to make sure I have the car revved up between 4-6K RPM or else things are a little stiff getting into 2nd gear. Here is what I did to make things shift better:
* Replaced bushings in coupler in tunnel between rear seats
* replace bushing in tunnel beneath shifter housing
* replaced cup bushing at bottom of shifter
* switched to Mobil 1 manual transmission oil
* switched to Sport motor mounts from Pelican Parts
* adjusted linkage to factory specs (per Bently book)
* Replaced and lubed clutch cable
* removed clutch return spring from pedal cluster (REALLY helps the pedal return fast)

The next thing I plan to do switch to a short shift kit as I think the shifter is worn out (at the pivot point), and there is some play in it.

deven07

Things could be worse...you could have a 901!

billwagnon

I just got a 73T - second is a problem.

I thought the RPMs were too high when I was shifting and the synchro couldn't catch up - is this the wrong guess? If I pause ever-so-slightly between 1st and 2nd it slides right in, and I thought the pause just let the motor wind down to lower RPMs that 2nd would accept.

Jdub

EuroC has a very nice list. Even if you decide to rebuild your 915, you must replace old bushes to ever hope to get the 915 to shift in an orderly manner. I went through all of the changes, pedal cluster rebuild, new horseshoe spring and clutch cable, bushes, adjusting before I finally threw in the towel and rebuilt (125K miles; SC).

However, you would spend your time wisely if, when you replaced your trans oil, you pulled the shift fork plate off the bottom of the trans and checked to ensure that the shift fork is FIRMLY bolted to the plate. These get loose and are a very, very common reason for bad shifting. You may need a replacement gasket, but the rest is a no-brainer so no excuse not to check this item.

When you do so, pull the fork from the plate and studs by removing the four bolts. Then pull the studs from the plate and Loctite them in after cleaning thoroughly (the double-bolt method works here both for pulling and rethreading the studs back into the plate proper: be careful not to strip the threads!).

Jw

cmoss

I have the same thing happen with my '80SC. I had the clutch and 123 synchros rebuilt. This really helped, but it still happens occasionally. I haven't done the bushings, but may. I'll definetly give the Swepco a try.
Cheers,
Chris

Mike hachey

Very easy fix. Get the rear of the car in the air,remove plate between jump seats in back you will see shift coupler. remove coupler boot,move transmision into N resting left between 1st and 2nd. Scribe male, female shaft and loosen bolt,incremently move female shaft forward towards front of car,tighten bolt,start car,go through all gears,reverse as well. Move until all gears are being collected with ease. Good luck,no sweat. Mike. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />