Navaros911

Guys,

There are many linkage threads, but none that I could find that explain why my shifter moves at a quarter of it's normal pace from the 1-2 plane to the 3-4 plane.
It's like watching it in slow motion.

Normally when I pop it out of 2nd it instantly jumps to the 3-4 plane... now it takes around 3 seconds.

It only does it sometimes.

I have noticed it is likely to occur when it's hot and/or humid.

It's as if it's binding somewhere.

Shifting is great and smooth. So I don't think it's a gear box issue.

Anybody experience the same?
Anybody with the magical tip or other advice?

Navaros911

Since I'm either not explaining properly or nobody has had this, here's a three second video to show what I'm talking about.

The condition it occurs in is when it's HOT. It often means it's humid here as well.
It comes and goes, but generally is there when the car is really hot. Like driven in anger for 15 minutes in 100+ degrees.

Front back glides fine, the gearbox itself is doing just fine... it's just like it's stick ONLY like I'm showing. The 5th back to 3-4 is just fine.

Anybody got any clues?

Navaros911

Vid looks pretty bad... but it's better than nothing.

Rocket Rob

Have you inspected the ball & socket at the bottom of the shifter? When I bought my C2, the shifter felt odd but the transmission worked fine. I found that the plastic in the socket had deteriorated. There were fragments of plastic impeding the movement of the shifter ball. I replaced it and it feels normal again.

Alan 91 C2

There are lot's of moving parts to the trans shifter. there are plastic bushings at each end of the shifter tube support. I recently replaced all the plastic parts, as they had fallen apart. Best to work on a lift, as the work is done from under the car.

Navaros911

Just to update this thread in case someone else experiences this issue, what has been done and didn't make a difference is:

Replace the plastic bushings of the linkage
Replace the gearbox oil with the original stuff

Now, while isolating the problem to the gearbox I decided to adjust an eccentric bolt on the front right side of the box. This has made a difference and made the car drive able again when hot. I don't know what exactly it does, but the outcome is positive.

I am not 100% happy with how it is yet, but significantly better than before. The adjustment was only for 1/4 of a turn clockwise.

Can anybody tell me what this bolt actually does?

Looked at diagrams, but can't figure it out.

Now in the whole process I must've done something not right as the cat pops out of 2 nd when cornering hard on bumpy surface.

Any tips about this?

Navaros911

So now that the weather has started to heat up again, I can say it's as bad, if not worse, than before.

My mechanic checked the linkages and can't find anything out of the ordinary, just like my finding.

So now he's thinking it's in the box.

Now prior to just jumping in it, like I did with the engine rebuild - which may not have been needed, I would like to get some experts to chime in on this.

As I'm travelling and in Belgium next week, I'll check out two shops that supposedly rebuild transmissions to see what they say and post back.

Andy Roe

I have the same thing and my mechanic said it's something in the gearbox too. I'm interested to hear if someone knows what the actual cause is inside the gearbox.

Navaros911

Went to a specialist in mainland EU and he believes it is a simple bearing which sits in the box itself and that the selector shaft from the stick moves left and right in. It only rotates a little. He was kind enough to show me a few boxes, which he had laying open.

He said that the rod expands at a different rate as the rest of the box, loading up the ball bearing. However, he reckons my bearing is worn and doesn't have perfect round ***** anymore or the race is not perfect. It could also have been accelerated by debris. Either way, he says the rod expands and because of the lack of roundness, it starts to "lock" the rod in its place. My 3-4 plane and 5 plane movement is not stiff, only the R to 1-2 and on to 3-4 plane movement is stiff.

He even went as far as to say it is probably less than $50 in parts, but labor will be in the thousands. And, since we'll be in there, syncros and any sleeves that are worn should get replaces... I burnt my clutch badly once, so the flywheel and clutch should be replaced too... and so on.

All in all, not good news for such a simple failure.

I will go ahead with this at some time in the near future. Travelling at the moment.

Andy Roe

OK, thanks for the update. It's good to know what the likley cause of it is then.

Andy Roe

To update this, I've just done about 2000 miles in mine over a weekend and (touch wood) it seems to have gone away. I've always thought my 964 runs better with use and this is proof!!

I spoke to a Nick Fulljames from Redtek about it and he said it's fairly common with 993's. His thoughts were that some dirt/debris has got into the box and it's this which causes the stiffness when hot. He said it's usually a fairly easy fix.