Clutch Overheating Or On Its Way Out?

[32GTRB]

Anyone experienced a similar issue to mine? R32 GTR with standard box and exedy HD clutch. Car is making 300awkw.

My clutch isn't slipping when under WOT under load, but has problems grabbing after riding it a little (usually after going up my driveway which is painfully steep, although not too long). Is this a sign of a worn clutch or could it simply be the fluid needing replacement? It happens pretty quickly even after riding it only a little.

Anyway to tell for certain? The reservoir is at the max line and fluid looks ok.

cheers,j

[Micah.]

Mine start to smell If I ride it too much. which I really shouldn't do but sometimes get lazy. Or if I flog it and drop the clutch off the line. If it happens straight away when you start it i'd say it's on it's way out. Shouldn't happen that quickly. But I'm no mechanic.

[GH05T]

is the clutch grab point right near the floor?

[32GTRB]

  On 27/01/2015 at 6:43 AM, GH05T said:

is the clutch grab point right near the floor?

Nope its quite high.

[MrStabby]

What's the rating on the clutch? If its just a regular organic single then i think they're usually rated to more like 250kw, but organics are ok with a bit of riding unlike other clutch types.

No slip at WOT means its not worn out, and its handling the power.... Doesn't sound like a hydraulic problem. Weird.

[32GTRB]

  On 27/01/2015 at 8:11 AM, MrStabby said:

What's the rating on the clutch? If its just a regular organic single then i think they're usually rated to more like 250kw, but organics are ok with a bit of riding unlike other clutch types.

No slip at WOT means its not worn out, and its handling the power.... Doesn't sound like a hydraulic problem. Weird.

not sure as i bought the car with the clutch in it. Have been told its an excedy hd. could possibly be a twin plate as its very bitey. thinking i'll flush out the fluid with some new rbf600 and then see if it keeps doing it.

[GTRPSI]

Bleed your clutch lines and if its still grabbing high adjust the rod under the dash so the pedal will grab lower to the floor first.

Hopefully you have not burnt it out yet.

Exedy HD will hold a bit over 300 at all 4 when in good nick, once you start doing 4WD launches with it and slipping it, the burning smell will start once worn and then its all down hill from there.....

[Dobz]

Exactly how high is the take up point of the clutch, does it disengage with the slightest push on the pedal?

[32GTRB]

  On 27/01/2015 at 10:10 AM, Dobz said:

Exactly how high is the take up point of the clutch, does it disengage with the slightest push on the pedal?

its fairly high but does not disengage on a slight push.

I have noted that it doesn't seem to bite at the same spot on occasion, thinking it might very well be the adjustment/fluid?

[GTRPSI]

If the grab point chages either your fuild needs bleeding or the clutch pedal braket has cracked, yes they are known to do so.

[32GTRB]

had a look and adjusted the clutch. Bracket seems fine. I adjusted the clutch so that when the clutch is fully released, it sits flush against the sensor. This should also be the max bottom adjustment possible (correct me if I'm wrong).

Will test out the car tomorrow, there was only a little bit of adjustment needed to make it sit flush.

[32GTRB]

Update: clutch adjustment seemed to fix it! Don't think the clutch was fully engaging at times due to the way it was adjusted, have noticed today that it seems much easier to drive and doesn't feel like slipping at all.

Was very easy to do for those who may be having a similar issue. There are two things which need to be adjusted, the pressure switch (not sure what this does, but assume it tells the car the switch is released when you step on the clutch), and the pedal itself.

Adjusting the switch (step 1)

1. Get under the dash where the pedals are, follow the clutch pedal to where it connects to the bracket and you'll see two adjustable threaded bits (technical term), one in front of the pedal (towards the seat) and one behind (which i assume goes into the clutch slave).

2. Loosen the nut in front of the pedal with a 14mm spanner. Doing so allows you to turn the sensor. To adjust, simply rotate the sensor (with the plug on it) which will in turn push the pressure switch at the end in or out. I backed my out so that the threaded bit sat flush against the welded nut on the bracket.

3. tighten the lock nut back up, and now its time to adjust the pedal.

Adjusting the pedal.

4. Now that you've adjusted the switch, you want to adjust the pedal so that when its fully released, the rubber bit on the pedal completely pushes the pressure switch in, sitting flush against the lock nut but not any further. This should then give you the optimal clutch setting (correct me if I'm wrong).

5. The process of doing so is pretty much the same as adjusting the sensor, except after loosening the lock up (see 3. on pic below) you want to turn the threaded shaft with some needle nose pliers to move the pedal. You'll notice the rubber bit (see "rubber bit" on pic) moving backwards or forwards as you do this.

6. Simply turn the threaded shaft appropriately so that when fully released, it sits flush against the lock nut (2) without any additional pressure being applied. Once you have it flush, tighten up the lock up (you may want to hold onto the gold bracket at the end of the threaded shaft while tightening in case the bracket bends as it turns when you tighten the nut).

And a pic for reference

Edited January 28, 2015 by Jaeyon

[GTSBoy]

Just ref the above.....the switch doesn't really matter (as in, adjusting it doesn't really matter). The ECU uses it to know when the clutch is depressed. But it doesn't need to know the instant that you start to push it - it really only needs to know that the pedal is down. So adjust it or not. Do it before you do the pedal or not, but don't put too much care into it. Clearly, if someone has buggered around with it and it is somehow stopping the pedal from returning all the way to it's own top stop, THEN you'd want to do something about it before starting on the pedal.

The correct adjustment for the pedal is to set it so that there is a small amount of freeplay at the top of the stroke before you feel the clutch take up on the release bearing. 15mm or so of pedal stroke is in the right ballpark, possibly/probably a bit less if you can reliably feel it. You DO NOT want it to have no freeplay because then the clutch is always leaning on the release bearing, which will wear it out. And it will also possibly mean that the clutch is actually partially released when it is supposed to be engaged, which is obviously bad. You also don't want heaps of freeplay because a) it feels bad and b) it leads to a low pedal with insufficient clutch actuation - meaning you might not be able to release the clutch completely.

Edited January 28, 2015 by GTSBoy