Why after adjusting the clutch to a point where when engaging into first or second there are no grinds on a cold start....
but after the car is hot it begins to grind in first second, and third does not engage as well
does the cable expand this much from the heat??

I have the same problem. It doesn't grind, but it fights me for first when hot. I have to do the 2nd back to first thing. Or slip the clutch while I'm trying to engage first.

Mine does this the worst when its completely heat soaked. I do have a eurorace header which cooks my cable. Even though its insulated with thermal wrap, its still a nuisance.

I've been able to correct it some by adjusting my shifter, but I can't find a "sweet spot" where everything works perfect. If I get first to work good, my 3rd to 4th shift suffers. If I get my 3rd to 4th shift to work, my 1st gear suffers. My linkage is all rebuilt. My console bushing is the PMS bronze unit. And, I have a Rennshifter.

Story of my life. I think the cable streches when it gets hot.

is it the cable, the shift rod, or the tranny itself that reacts to the heat??

My guess would be the cable. After thinking about it, I'm tempted to adjust my clutch a little tight so when/if the cable stretches, its adjusted right. But, I would hate to put excess tension on the cable when its just sitting in the garage. I've also considered trying a Terrycable.

My first thought was about the oil. Seems to me that this is the most temperature sensitive component.

Did you pull the cable in and make the clutch release closer to the top of the pedal? Maybe you need to pull the trans out and put a washer behind the fork pivot ball so you have more fork travel to use.

I just recently did this on my car and my clutch releases about midway and so if the cable stretches I still have plenty of room.

Where does the clutch disengage in the pedal stroke? It should dissengauge in the 1st 1/4 of pedal travel. You should have no more than 3/4" of play in the pedal when it is fully out.

Cables do stretch over time, and with heat and you may need a new one. I like the more robust Terry cables.

Has your flywheel ever been machined?

These conversations always confuse me and I've adjusted my cable many times over the years and still don't know the answer.

When you say it should disengage in the first 1/4 of pedal travel, does that mean that your foot is off the pedal and only 1/4 of the way down, the engine will spin and the wheels will not?

And what exactly is "play" in the pedal. When your foot is off the pedal, is it the amount you can pull "up" (towards the driver) or is the amount you can gently push "down" (toward the floor) before your foot feels any resistance as the cable begins to take up tension?

And when your foot is totally pushed into the floorboard, as you let up on the clutch, when (distance or percentage of travel?) should the clutch begin to engage?

I will be forever grateful for the answers, O Doc of Evil!

Paul

Within the 1st 1/4 of travel is the 1st 1/4 of travel if you take the whole of travel and divide it by 1/4ths. So, by the time you have covered 1/4 of the total travel during depressing the pedal, the clutch should be released.

Given the previous, when releasing the clutch pedal you should fell the clutch grab at about 3/4 travel on the way back up.

Play refers to neutral movement. You should be able to move the pedal up and down with no resistance (it should be loose) about 3/4 inch. The pedal will ultimately rest at the low end of this travel so you should be able to pull it back towards the aft of the car 3/4".


Clear as mud?

I think your bronze bushing is binding. You can't get clean shifting full left and right of the pattern at the same time because the bushing is limiting the off-axis rotation of the shift rod. The factory plastic bushing is hourglass shaped to prevent binding.

Were talking about the console bushing correct? #55?

Click to view attachment

Yes, but a bronze bushing at the firewall can have the same effect.

If the factory console bushing is eccentric, will it orient itself correctly? I would imagine so, since most tranny consoles are so wallowed out. I have a new factory one, I will have to try that when it cools down here. I can see how a little lash there, would make a difference.

It's not eccentric, the sides of the inner hole splay out from the center to allow the shift rod to pivot in the hole.

OK, I'm with you now.

Yes, doc, thanks. What's really clear is that my clutch engages/disengages WAY too close to the floor! Looks like the pedal should engage up near the top. Thus, my clutch should start grabbing more proximal than distal!

I'll readjust my clutch and then play with the free play.

Paul

As you adjust the clutch, the free play is also adjusted. When you are under your car, you should not be able to get much varis/valgas deflection in the cable. To get such is a sure indicator that your cable is too slack. What I recommend is to tighten the cable until it is taught, go and check the pedal play, loosen/tighten as indicated.

Proximal=toward the center
Distal=away from the center
Varus=bent inward
Valgus=bent outward

Enough you guys, it's a car for heaven sakes

He started it with the proximal/distal talk

If you have a EuroRace header, it has been suggested to relocate the clutch pedal under the header rather then above it. That should help with the heat issues associated. There are a thread on this mod earlier.

Zach

You mean clutch cable, not pedal, right?

Do you mean the trick where you rotate the cable stop/pulley mount downward?

Mine is above the header, but the way its routed is pretty clean. It never touches the header and its well insulated.

OK. Doc is in medical school. He admits he should be studying. But he's hanging on the board.

So, in a somewhat selfish move, I elect to get the info I need AND contribute to Evil's education.

I'm just a nice guy. what can I say?

Paul

yo,
da cable be wrong...turn the nut till its right.

Rich

does this issue have anything to do with the heat of the tranny?, or the fluid in the tranny??

If the flywheel has been machined (most have) the pivot (throwout arm) must be shimmed out correctly too!!

another damn cause of goofy shifting that has to be addressed for everything to work right...

i was hoping not to drop the motor this winter..again
and maybe just stick to flaring the car for a winters project....
i will tighten the nuts up for now...

If you are running out of thread on the cable end, which is a common occurrence, you can put a small piece of metal tubing on the end of the cable between the wedge block and the adjusting nut.

You do not need to drop the engine to remove the tranny! Its easier not to.

not to hijack, but it seems to me with this clutch design, the throwout bearing is ALWAYS pressed up against the pressure plate? And the clutch pedal has a spring that pushes it towards the floor, right? So by free play of 3/4" you mean the pedal only feels resistance from this pedal spring and not any pressure plate action...I think.

I kept tightening the nut until the cable was taut but the TO bearing wasn't starting to compress the PP. The clutch pedal cannot be lifted any more, but does depress about 1/2" before I feel that the PP is starting to be compressed. Am I doing this wrong?

thanks for any help!!

You did the adjustment right, but your theory is off a bit. There is no spring in the clutch pedal assembly itself. The only spring you feel is the spring of the pressure plate. Thus, you tighten the cable to make the TO bearing stay against the plate, but not so tight that it is hard against the plate (as demonstrated by the 3/4-1/2" of wiggle in the pedal).

Is that clearer?

yes, thanks!

i'm glad you guys are hashing this out because i'm going to need to readjust my clutch and shim up the flywheel because it is getting flippin ridiculous to grind gears.

You dont shim the flywheel, you put a washer under the clutch fork pivot ball. You will also need to put some Teflon tape on the pivot ball threads when you shim it as it will leak oil otherwise.
Did your mechanic adjust this for you yet?

he adjusted the clutch but i have the same problem when the car has been warmed up...it tends to grind when the car is warm but i experience no problems when the car is cold.

i didnt mean shim the flywheel i meant put the washer under the fork pivot ball.

where do i get a bronze bushing, and what is the part number?

Thomas, I suspect that your clutch is not adjusted correctly = cable tight enough when cold, too loose when hot. I have posted above how to check it. It is easy and you should have no problem doing it yourself.

When does the clutch disengage in the pedal travel when cold? Hot? I bet they are different.

How much play do you have with in your pedal at the top when cold? Hot? Again, I would bet they are different.

Your cable should be adjusted so that it meets the aforementioned criteria when it is hot. Thus, at its hottest and slackest it should have no more than 3/4" pedal slop and should disengage the clutch in the bottom of the 1st 1/4 of pedal travel.

The bronze bushing at the fire wall is an after market part and is meant to replace #41. James sells these.

Mine used to do that when my engine ran really hot/lean, even after I adjusted the clutch. I tuned it so it runs rich and operates at about ~210 degrees (oil temp) and it hasn't done it since.


This probably isn't applicable to the situation but...