Gearchange question

[nfearn]

My "new" 993 is settling into its new life quite well, with just a few niggles to resolve.

One thing I've noticed though is that, when changing out of a gear with the clutch fully down and the engine idling (and doing more than about 20mph), the gearlever is quite reluctant to come out of the gear position it's in and into the neutral plane. However, if some revs are applied (as would normally be the case anyway for rev-matching purposes) the lever slips easily out of gear with only "normal" pressure.

This seems to happen with all gears from second to sixth, so it can't be wear on a particular gear cluster. The gearbox oil has been changed very recently with the correct specification oil.

My question is this: is this normal or not? And if not, does anybody know what might cause it and whether this is indicative of bigger problems in the future?

regards
Nick

 

[mmylonas]

Not normal on my car (although have had similar issues on an ol Alfa Bertone Coupe that I run). Interested to hear any diagnostic advice from others.

 

[Porker993]

Maybe it's a clutch issue ? Clutch master/slave cylinder ? Maybe the clutch is not disengaging fully. Hopefully that is all it is, as that is a fairly cheap fix.

 

[jboult]

I had some similar issues, the most embarrassing being 'stuck' in 3rd gear at a set of lights after pulling up sharply and not changing down. The clutch pedal would sometimes 'hang' as well, which is fairly common. A new slave cylinder sorted all that out.

After that, I still had a slight notchiness to the gear change - with revs on and fast changes it was perfect, slower changes were more awkward and like you it felt slightly reluctant to move out of gear. Different gear box oil (heavier? Camtune/Porsche Byfleet diagnosed the problem) fixed that.

Perfectly good for a couple of years - and now a broken link in the gearbox means it's currently being rebuilt. The joys of a classic car...

Cheers/John

 

[nfearn]

Thanks for the input guys. I am inclined to think it is clutch-related, since it happens in all gears.

The car's being serviced next week so hopefully they'll be able to shed some light on it.

regards
Nick

 

[ach]

It is clutch related and most probably the issue is in slave cylinder. I had similar problem some years ago with an old Audi.

Hope you will sort this out at the service

 

[nfearn]

Thanks - that is reassuring. I've been out for a drive this evening and it seems to me that if I press the clutch down two or three times in quick succession before attempting to move out of a gear, the gear disengages easily, which tends to argue it's clutch related.

The garage will be bleeding the clutch hydraulics of the no doubt 16-year-old fluid as the first step.

I'll report back once the car's back with me, hopefully with good news.

Nick

 

[nfearn]

So, the car's back with me following its 24,000 mile service with Autostrasse - including a clutch bleed - and the gearchange problem seems to be improving. I can't be too specific since I've not had a chance to drive the car other than back from the garage (15 miles on primary routes) but I hope to have some more time in the next two to three days to form an opinion.

I've been wondering about the mechanism by which the gears become reluctant to disengage and wonder if the driven plate is sticking slightly on the gearbox's input shaft splines, preventing it from disengaging from the flywheel when the clutch is depressed.

This would, I think, give rise to the symptom I'm experiencing but equally, should also lead to clutch-drag symptoms when stationary, which I don't have. Unless, that is, the difference in speed between flywheel and input shaft is enough to throw the driven plate off the flywheel's friction surface under those conditions...

Anyway, subjectively it seems to be improving, which argues that it could just be a lack of use problem.

If anyone can offer any suggestions as to the cause of the problem though I would be interested to hear them.

regards

 

[Stuart Hatfield]

Try changing the g box oil check drain plug , magnetic ,anything stuck to it, mine had a couple of needle rollers on it ended up changing the diff ,not a hard job ,not saying thats your problem just what i had, stiff gear change.

 

[nfearn]

Hi Stuart

The gearbox oil was changed about 500 miles ago - drain and fill plugs were both pretty clean (minor metal dust but nothing solid). I'm going to be doing 600 or so miles in the car in the next couple of days and hopefully that will loosen things up a little.

regards
Nick

 

[nfearn]

Well, I've covered another 700 miles in the car and the problem is beginning to go away. The service didn't reveal anything about the clutch (it was bled out though).

My suspicions centre around the driven plate being stiff on the input shaft splines. Hopefully another couple of thousand miles will see it OK.

Nick

 

[nfearn]

I'm beginning to convince myself that my diagnosis is correct - i.e. that the driven plate is sticking slightly on the splines and remaining "connected" to the flywheel.

The symptoms seem to be easing up. Hopefully the next couple of thousand miles will sort things out.

Nick

 

[nfearn]

To finally close the book on the "reluctant" gearchange issue, the clutch assembly itself was replaced last week. This has completely removed the remaining symptoms (slightly notchy clutch action, quiet creaking noise as clutch is depressed and released, and the occasional reluctance to come out of a gear.

The clutch was the original (1993 date stamp) and actually had quite a bit of life left in it from a friction material perspective.

However the clutch action is much, much smoother and lighter now, and feels much as it must have done when the car was brand new.

Note that my car has also had a new MPL clutch slave cylinder previously fitted (see MPL slave cylinder thread), a new slave cylinder flexi hose, comprehensive cleaning and lubrication of the clutch pedal and gear change (lever-end) assemblies and new hydraulic fluid).

Now, for some driving...

Nick