Clutch freeplay
 

Sorry to start another topic about this but I've tried googling it and couldn't find a good, clear answer. I also asked in another thread but the thread died before I got an answer.

I'm trying to adjust to zero freeplay, as per billman and others' recommendations. My clutch and transmission don't have any issues (that I know of) but I'm trying to make sure that my pedal is adjusted correctly (especially since it's so easy to do).

I went under the driver's side to observe what was going on when depressing the pedal. I have about 1-2" where I have no resistance - basically I can push it down by resting my pinky finger on it. After the 1-2" I then feel the resistance (hydraulic pressure?). However, the rod moves as soon as I move the pedal, even without the resistance.

Is this the way it should be? Or should I adjust the nut out to where I feel resistance as soon as I start pushing the pedal?

Thanks! https://www.s2ki.com/s2000/public/st...t-tip-wink.gif

The rod always moves, you just don't want it so tight that the rod is butted up against the master cylinder piston. The piston is what the end of the rod butts up against at the contact point to push the piston inwards. When you feel no more play as you push the pedal down with your finger that is the contact point where the end of the rod is butted up against the mc piston, if you continue to push harder then the piston will begin to move and be engaged.

1-2 inches of play is a bit much IMO, so I say lengthen the rod to close up that distance. Honestly I could never understand how to get rid of all the freeplay mentioned in other posts, I tend to keep about 1/4 - 1/2 inch play in the system, so the end of the rod is about 1/4 - 1/2 inches away from the master cylinder piston. I think that is safe and the extra 1/4 inch isn't going to factor into the operation of the tranny. A while back my clutch free play tightened up on it's own for some reason, and my clutch began to slip. So I say 1/4 inch to even 1/2 inch is good.

Ok, so when the term "play" or "freeplay" is used it's referring to the pedal depress movement that has no resistance and does not engage the clutch at all?

So basically, I need to adjust my pedal up so that I feel "resistance" from the CMC as soon as I start depressing the clutch pedal?

I say yes to the first question, and almost to the second question. I still prefer a bit of movement before the cmc piston is engaged, say 1/4-1/2 inch ?, that gives you a bit of leeway should things ever tighten up later down the road. Just my preference here as it did happen to me once, so I prefer a margin of safety there over tightening it up the entire distance. So the clutch rod isn't completely tight, I will lengthen the rod until it makes light contact with the piston and then I will back it off a bit so there is still some play there. I hope this helps, it might not be what everyone else does but that is my preferred method.

Ok great, thanks. I just measured it exactly last night and it was actually more like 1" of freeplay. I think I'm going to go your route and adjust it to about 1/4" as well just in case it does tighten up like you said.

Thanks for the help :tipwink:

Ok great, thanks. I just measured it exactly last night and it was actually more like 1" of freeplay. I think I'm going to go your route and adjust it to about 1/4" as well just in case it does tighten up like you said.

Thanks for the help :tipwink:
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When you are trying to measure the clearance look at the end of the clutch rod as you are moving the pedal with your finger, there is a disc on the end of the rod, that is where the clearance should be, between the disc on the end of the clutch rod and the master cylinder piston contact point. Try to get the 1/4 inch clearance at that point. It is possible that the pedal can move 1/4-1/2 inch but the clutch rod has no clearance, so look at the end of the rod as you are moving the pedal to see if there is clearance there. Good luck.

Ok great, thanks. I just measured it exactly last night and it was actually more like 1" of freeplay. I think I'm going to go your route and adjust it to about 1/4" as well just in case it does tighten up like you said.

Thanks for the help :tipwink:
[/quote]

When you are trying to measure the clearance look at the end of the clutch rod as you are moving the pedal with your finger, there is a disc on the end of the rod, that is where the clearance should be, between the disc on the end of the clutch rod and the master cylinder piston contact point. Try to get the 1/4 inch clearance at that point. It is possible that the pedal can move 1/4-1/2 inch but the clutch rod has no clearance, so look at the end of the rod as you are moving the pedal to see if there is clearance there. Good luck.
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So since the disc on the end of the rod covers any visible contact point, the 'contact point' of the rod (disc) to the CMC piston is just based on feel, right?
Also, it the 'freeplay' measurement the clutch travel distance or the rod disc travel distance? I'm assuming they would be different.

Ok great, thanks. I just measured it exactly last night and it was actually more like 1" of freeplay. I think I'm going to go your route and adjust it to about 1/4" as well just in case it does tighten up like you said.

Thanks for the help :tipwink:
[/quote]

When you are trying to measure the clearance look at the end of the clutch rod as you are moving the pedal with your finger, there is a disc on the end of the rod, that is where the clearance should be, between the disc on the end of the clutch rod and the master cylinder piston contact point. Try to get the 1/4 inch clearance at that point. It is possible that the pedal can move 1/4-1/2 inch but the clutch rod has no clearance, so look at the end of the rod as you are moving the pedal to see if there is clearance there. Good luck.
[/quote]
So since the disc on the end of the rod covers any visible contact point, the 'contact point' of the rod (disc) to the CMC piston is just based on feel, right?
Also, it the 'freeplay' measurement the clutch travel distance or the rod disc travel distance? I'm assuming they would be different.
[/quote]

That is correct, you can't really see the piston part but you can see the rod disc moving and you can see when it hits the cmc rod piston, the difference is the amount of freeplay. So move the pedal but watch the end of the clutch rod.

The amount of movement in the pedal is different/larger than the amount that the rod disc travels. Let me amend my distance calculation now that I am looking at a ruler. The clearance from the end of the clutch rod disc and the cmc piston is more like 1/8th of an inch to 1/4 inch, 1/2 inch would be way too much. The pedal movement is probably going to be more like 1/4 to 1/2 inch. The main thing is that you don't want the clutch rod disc pushing on the cmc piston with zero clearance, and of course you don't want excessive freeplay. I always eyeball it, so coming up with firm measurements is tricky.

Just to add to all the good things JFUSHION said, a small amount of play is always desired so you can be sure that at rest the clutch isn't being engaged at all. Not only so that later after some miles you'll be able to tell if things have tightened up and now at rest clutch IS being engaged some (and now requires adjustment to prevent slipping), but even at the time you are adjusting it, if trying for zero play its difficult to tell if you are really at zero or if clutch is now being engaged at rest.

In other words, at adjustment time its difficult to tell the difference between zero play and adjusted too far.

I did mine recently and it's best to get under there and look for yourself. You don't want the rod at the firewall to have any preload. For me, this was about 1/2" of pedal freeplay. I then did another full turn more loose to be sure.