Gearbox problems!
Turbo Mini Forums

So the gearbox that has only done around a 1000 miles or less has started crunching going from 3rd to 2nd. So much so that it just won't go in to gear.

I have a pre vert clutch set up with grey diaphragm that seem light/ spongy :/ I have tried bleeding clutch properly and set the adjustment again but with no improved feel.
The gearbox has the ''uprated'' moly coated baulk rings but whatever they are they should last longer than this! It is also a bit of a pain getting it into reverse.

New clevis pins in the top of the clutch pedal, not very old master cylinder, new clutch arm and pin, not very old slave cylinder. With all of that i can only think i need to whip the engine out and check the gearbox out :(

Any other avenues that could be affecting this?

Cheers
Dan.

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Pedal shouldn't be spongy, fix that before you pull it out.

If something is worth doing, it's worth doing half of.

Sounds like adjustment to me, and or bleeding still? Are you using a braided hose between the master and slave?
Check the arms not bent or the ball's not overly worn (imho well worth investing in either the MED or Force racing arms). I've also known through high mileage the hole in the pedal where the clevis pin goes through to elongate and cause travel.

Not sure spongy is the right word John, but to me it doesn't feel heavy at all and i know from people saying on here that it should be! I am using a braided line from master to slave and i have ordered the MED arm so i think i will try that. If not then i can't think what would cause this.

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How many miles has the engine done

How many miles has the engine done

Engine was also newly rebuilt with the gearbox, around a 1000 miles.

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Well reverse has no baulk rings so if 2nd and R are having the same problem i would look at the clutch not disengaging (sp?) First

Yes i moved to the darkside

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To discount the hydraulics Check that you have 0.5" travel on the arm from off to on.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

Have you got straight cut drops? And if so do they rattle on idle?

If they don't it could be the primary gear not spinning free enough on the crank?

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1/4mile in 13.2sec @ 111 terminal on 15psi

Edit, if you bleed it though. Then bleed it though a bit later do you still get more air in there?

A knackered master cylinder caused my clutch to never be quite right and regularly needed bleeding. I'd probably change the slave first though as that is cheap.

I also needed to bend the release arm to make sure it disengaged properly even after the hydraulics were working right.

Edited by minimole23 on 10th Jun, 2013.

as above sounds like a clutch disengagement problem have you looked at the peddle box like Cables69 says i had a badly worn pin under the dash resulting in to much free play making it hard/ a "clunk" to grab reverse gear it was a pig of a job getting under there with some long long nose pliers lol

dont pull it till you have tried everything else lol

Right i've bought some replacement bits to try this weekend, to hopefully sort the clutch issues before i pull the engine out.

One of the items i got to try was the clutch arm plunger pin, that goes into the slave.
Now the one i had in measured 83mm and the new one i have measures 69mm!

Any reason for this? Which ones best to use?

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Right so rather than start another thread, i will update this on.

After further inspection i have taken the pressure plate off and it is rather worn all ready! It's only done a 1000 miles or so, it looks like the release bearing has been riding on it.

So is this an adjustment issue, and can i get a replacement thrust plate or is it a new pressure plate i'm going to have to get. It's a grey diaphragm.

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That is caused by not adjusting the return stop correctly which inturn will mean the throwout stop adjustment is also wrong.
You can get just a thrust plate, you dont need to replace the whole diaphragm

I seriously doubt it!

We had this often with the upside down skip. We ran a bent clutch arm. I reckon it was bent to far, so the release bearing was always engaged slightly. We ended up with two very worn centres like that and several sets of munched thrusts.

On my car I have an MED arm with a longer pin which I have shortened until it was a good fit.

I see, well there was no stalling when i dipped the clutch so i don't think its munched the thrusts yet. I have bought an MED clutch arm and new clevis pins ect. Whats does having a longer pin achieve?

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It makes it so that it doesn't have about 8-10mm of travel at the slave cylinder before engaging the pin...

Hi

Were older thrust plates hardened? i have heard of a number of issues around new clutches similar to this . some builders are reusing the old plates

I have been running with my thrust bearing permanently pushing on the thrust plate for a long time, but never seen that issue before.
I'd take a look at the bearing first - and make sure it is spinning freely. To wear like that,,, something is definately amiss.
What earwax says might be worth a look - I have never bought a new thrust plate, so mine would have been old-school parts.

I take it you have the correct release bearing fitted? Not a verto or an odd ball bearing?

Turbodave, the brave man with no clutch arm return spring

Yeah got the correct bearing fitted and it's spinning freely, doesn't feel like its full of grit or anything.

Thats an interesting one on the thrust plate. I've had a look and can't seem to find anywhere that sells them separately.

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I'm sure one of us will have an old one knocking about, I will have a look tonight

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

I've not run a return spring fo0r 10 years.

On 17th Jun, 2013 Vegard said:
Turbodave, the brave man with no clutch arm return spring

Fastest 998 mini in the world? 13.05 1/4 mile 106mph