Unkle

Hi
I am slowly working through the car, finding little bits i want to improve/replace purely for my own piece of mind, and i have had an issue develop with 2nd gear recently.

The gearbox is smooth and quiet, the clutch was replaced a couple of years ago and hasn't covered many miles (perhaps 10 to 20k) engine mounts just changed. But recently it has started to occasionally pop out of 2nd gear. It does it randomly, and at first i thought perhaps i wasn't engaging the gear enough. but i have been taking my time and emphasising the change into 2nd to see if it was me. But i don't think it is.

It does it on lift off, it doesn't especially do it only when decelerating from high speed but also in traffic. It also does it at constant throttle when driving slow and in traffic perhaps 3 times in a 20 mins drive, but not always, so you could drive for an hour or 2 without it happening. These aren't the exclusive times it does it but its not like it does it when driving hard.

Any ideas welcome, preferably starting with the cheapest


thanks in advance

ChaseN

Hook a bungee cord at the rear of the e-brake handle. Then, every time you shift into second, loop the bungee around it to hold it in there nice and tight.

Hey, you said cheapest first

Unkle

lol Thanks it may come to that.

Just hope someone doesn't start with worn Synchro

I sent a PM to a member called Meek, as he seems to have had a similar issue on his C4

meek

Unkle, yes, I have exactly the same issue with my C4. Is your car a C4 or C2? It happens very rarely, but is annoying when it does. Another poster had this and posted a year or so ago with his solution, which was to replace the orbital clucth plates ( pretty cheap ); his mech. diagnosed excessive play through wear. Solved it for him, or so he said back then. My own mech. thinks this is nonsense (!) and says it is a relatively simple gearbox issue - can't remember what it was now, as I decided to leave it until the next clutch change and the box needs dropping anyway. I have left a message for him to come back to me on it. Will post what he says.

Unkle

Hi Meek

Yeah it is a C4 1993 (1992 build). I have never heard the words "simple" and "gearbox" in the same sentence, so i would be interested in the reply.

Does your car still do it randomly? Did it get worse?

Mine doesn't seem to be connected to large changes from acceleration to deceleration so its not a movement issue i assume especially as i have new mounts all round. I can be plodding along in traffic at 2000 rpm or 3000 rpm and it does it. Or entering a round about, or any number of random times. Just not very frequently

meek

I have just spoken to my mech. and he says 2nd gear guide sleeve worn - part is £624 +VAT. He said he has seen it before on C2 and C4, though not that common; lucky us! Sees it more often on later cars. He is not convinced on the orbital gear fix, as he had a C4 in recently that had had the oribital clutches incorrectly fitted and it still functioned without any issues. Like you, I am not convinced by the orbital idea as the issue isn't limited to sudden deceleration; it can pop out randomly just cruising about town. Perhaps Porsche had a dodgy batch of gudie sleeves which are only now starting to show up? Either way, I will not be doing anything about it until clutch time. It hasn't gotten any worse over the past 3 years.

Unkle

Thanks very much for the info. What is also good to here is that you seem to have had the issue for some time without it getting worse. Although it would have been nice if it was only an adjustment issue.

Without getting too technical I had a look at the workshop manual I have and cannot find the sleeve, not that it is of major concern as we all tend to have more than one name for everything on a car, but wanted to check its location and whether oil plays a significant part. Just like oil viscosity can on a synchro.

Do you know if the issue can be reduced with a change in oil or an additive, or am i clutching at straws? Let me rephrase that, i know I'm clutching at straws, but every little helps

meek

I am not sure about oil making a difference to this issue. Someone with a better understanding than me ( not difficult! ) may be able to offer advice on that. I reckon I will be up for a clutch change next year, so will proably get it fixed properly then. Will save a few £s doing it all at the same time. PS may even shorten the gears as per the other thread that is on-going; it is not as if I need to get to 160mph.

klr10

Hi Meek, no more jumping out of gear since the clutches were changed. Am currently in the process of having the brake boost pump pressure switch changed (emptied all over the garage floor). Love my 964 to bits, but why can't it be like my twenty year old Honda? 200bhp 3 litre V6 never breaks? I know I know....

meek

That is good to know K. I can't remember now; did you have any work done to the gearbox on yours before you went the clucth route? I seem to recall you trying something else first.

klr10

I think we tried new gearbox mounts, but the clutches did make a big difference to the feel of the gearstick, it's much tighter (I've no idea about the gearbox internals, so not much good at explaining why the clutches helped, except to say they had a lot of play in them apparently)

Indycam

Popping out of gear can be an internal or external problem .
If you don't get it all the way "into" gear it can pop out of gear .
You stated that you were carefully putting it into gear but that is not the test .
You could be pushing the shift lever all the way while the gear isn't being pushed all the way .
You may need to get under the car and push it all the way into gear at the transaxle .

"engine mounts just changed."
This makes me wonder if the problem is maybe a linkage adjustment problem .
If the motor/ transaxle is sitting just a slight bit fore or aft of where it was sitting ...
Or if the shift linkage got stressed during the motor mount replacement ...

StanUK951

I had a very similar issue on my 1991 C4. It turned out to be gearbox mounts. It only affected 2nd gear and was very random, mostly in corners but also stop start traffic. I wouldn't discount mounts straightaway. Start with the simple things first...! Good luck.

meek

Mmm... I had thought of the whole issue of play in the linkage before, but couldn't find anything obvoius and having replaced the old engine mounts with RS mounts ( no improvement in the problem ) I assumed the box mount would have little effect on fore/aft movement. Perhaps I should try that. It is accessible without dropping the box, I think?

meek

UPDATE: I have replaced the gearbox mount and it appears to have resolved this issue for me. Obviously not a guarantee for everyone with the same problem, but StanUK951 and I seem to have had the same solution.