Gearbox and or clutch issues, experts needed pls!!

Hi people,

I know it's a lot of text, but please help - this is driving me crazy.

Late last year my 6 speed gearbox made an odd sound so I had it removed an inspected. Turns out that 6th gear had lost a tooth so I sourced a complete set of gearbox internals from Nigel on here. This was then fitted into my existing box (by a gearbox specialist) and refitted to my car (by my friend who has a garage), along with a new clutch, new slave cylinder and new nearside engine mount.

All was well for the first 30 miles but at approx 60mph when changing from 5th - 6th I noticed some incredible vibrations coming through the clutch pedal and this was still evident even after changing into gear. If it put my foot on the pedal lightly whilst in 6th it would make my whole leg shake/tingle. After coming off the motorway I noticed that pulling away in any gear, or even changing gears and getting the bite point, it would make the whole car shudder. I called my mate who assumed something had happened to the clutch and he said to get it to a specialist and not to bother paying him for the clutch change. Life has been a bit hectic and I haven't been able to do that, or anything with the car until this week.

So.... This week, after the car had been standing for 3 months, I charged it and tried to move it a little. The shudder was still there on bite point. So I checked the gearbox dipstick and couldn't really get a reading, so decided to top it up via the dipstick tube with a stupid amount of 500ml. I also checked the brake fluid level and removed the cap to check the colour. When I got back into the car, the clutch pedal was rock solid in the up position and couldn't be depressed. I took the battery tray out and found the slave cylinder was all the way open so I loosened the nipple, squeezed the slave in by hand, pushed the clutch pedal down then re tightened the nipple. This has cured the stiff clutch and weirdly I can pull away and drive the car with no shudder, no vibrating through the clutch pedal or anything... it drives like it should.... EXCEPT I seem to have gearbox oil dripping from between the bell housing and the engine, but this is not constant - when the car isn't being used, it's fine - but after having a short drive, it seems to be dripping again. So my questions are....


Did filling (or over filling) my gearbox oil cause my stiff clutch, if not then what?

If I have overfilled the gearbox by 500ml would it cause my box to be leaking from where it is, or has my 'new' gearbox been leaking oil and the shuddering/vibrating through the clutch pedal was due to me having no oil in it?

I had to push a length of pipe onto the dipstick tube in order to refill, I had to do this with some force so I suspect I could have made the dipstick O ring leak, if this is leaking would it look like its dripping from between the bell housing and engine?

I know the best thing to do would be to drain the box and refill but I've seen people say you can't really empty all of the oil out and if I can't get a reading on the stick, I don't want to risk over filling again - if that is indeed what I've done.

Opinions please

You need to be able to read the dipstick at least.
Take it out,clean it then dip it. Take it out and hold it to a light of some sort and try to feel the level on the stick with your finger or a tissue to see where it absorbs first.

Hi magooagain,

It's always been very difficult to get a reading off of the stick. I've managed it with the tissue blotting method in the past but now I can't seem to get a consistent reading at all. Before I topped up the oil it seemed bone dry but my dipstick now has a bend in it in the last 3 inches or so, so I don't know if this is impacting the reading.

I have read that there are two drain points on the gearbox, I'm assuming one is for correct filling and one for draining? If so, would draining the 'filling' one be sufficient to get the excess oil out?

I'd be tempted to eliminate the cheap stuff first - completely drain the gearbox and re-fill with the correct amount of the correct grade. Then completely bleed the clutch.

Over-filling the gearbox couldn't cause a stiff clutch, but it could cause weeping past the seals

If it still judders after that, you've got something mechanical going on.

If the gearbox input shaft seal has let oil past AND it has got on the friction material, you could get juddering as the clutch slips and grips intermittently

Oh, the joys of modded Coupe ownership....

You can overfill the 6sp box by as much as 1Ltr and it won't cause any issues, this is something else so I'd drain and check the oil and inspect the magnet sump plug for debris.

Thanks for the replies guys. Just to be clear the juddering on pulling away and vibrating pedal issue stopped after I fixed/bled the slave.

I'm unable to get it on a ramp until Thursday but I have checked the dipstick today, very hard to get a reading from cold but after a short drive around the block, I checked it again and it's very easy to see the level is 1 - 2cm above the full mark. However, if I give it a wipe & stick it back in, it almost comes out almost bone dry again.

Also the dripping from around the area it seems to be coming from does not start until I stay stationary for 20/30 seconds or so. How low is the dipstick connection to the gearbox & is it possible the leak could be coming from that when the oil drains to the bottom?

Thanks again.