Clutch disengagement issues

[Randy V.B.]

Hello ladies and gentlemen. Wondering if anyone has had this problem or could help with the problem I am having. I'll start from the beginning I guess. Year before last I installed a McLeod RST clutch in my 2015 1le. Worked ok but I always had somewhat of a click feeling in the clutch pedal when releasing, almost like the clutch was hanging on the spines and then would slip by and continue to engage. After a couple years of use I just kind of ignored it. the clutch slipped really bad two or three times and I just figured it was something I did wrong. Eventually i ruined the clutch by getting fluid on it, complete screwup on my part lol.

Present day , this winter I installed a new RXT McLeod and I'm just going through the break in process. Everything is working beautifully during the break in but I'm having an intermittent issue with the clutch not fully disengaging. I'll give an example, I idle up my gravel driveway with no throttle. Just let the engine idle and lug the car along slowely. When I go to push the clutch in it will not fully disengage. It's enough that the car is creeping and you cannot get it out of gear. But you can let the clutch out the rest of its normal engagement travel before the car will stop moving. Almost like 1 disk is still partially engaged in the other is disengaged.

Another time it will do it is when I'm parked on an incline, I'll go to start the car and the clutch is not fully disengaged and you either need to shut the car off or yank it out of first gear and depressed the clutch again and it will be fine.
All other times the clutch is working fine. Always disengaging fully and shifting perfect.

It's almost like the clutch is getting hung up on the spline when it is under stain. And I also still have the strange feeling click sensation in the peddle when I'm letting it out. Generally never in the same spot of pedal travel.

Stuff replased the last year is,
Pedal assembly right from gm
New throw out bearing assembly. Gm
New pilot bearing
Separate reservoir for master cylinder
Billet sleeve for master
I put approximately 1 quart of fluid bled through the system

I am approximately 700 clutch engagements into the 1200 suggested for the proper breaking from McLeod.

Any suggestions or ideas are welcome before I start tearing this transmission out again


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[FasNuf]

Don't mean to be a total self promoting baboon, but it is the easiest way to explain this.
McLeod RXT 1200 setup
You can jump to 8:13 if you want to go to the shim specs and procedure.
This may just be one reason for it not disengaging.

https://youtu.be/EbmA6-BloP4?si=BRT7pg0XoGgozocY

[Randy V.B.]

Originally Posted by FasNuf

Don't mean to be a total self promoting baboon, but it is the easiest way to explain this.
McLeod RXT 1200 setup
You can jump to 8:13 if you want to go to the shim specs and procedure.
This may just be one reason for it not disengaging.

https://youtu.be/EbmA6-BloP4?si=BRT7pg0XoGgozocY

Thanks for that. I'll check it out.


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[Randy V.B.]

Extremely informative video. Looks like I'll be removing the transmission again to check stuff more closely . Thanks again


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[FasNuf]

Thanks. It's also possible your slave isnt pushing the pressure plate far enough to disengage the disks. That should be looked at when you get it apart too. Good luck.

[Randy V.B.]

Originally Posted by FasNuf

Thanks. It's also possible your slave isnt pushing the pressure plate far enough to disengage the disks. That should be looked at when you get it apart too. Good luck.

The only thing that confuses me is why it's not doing it all the time. Only when the is a steady strain on the clutch and you try to disengage. All the other times it's flawless. That's what made me think of the splines being messed up with some kind of ridge or something. But I checked all that really close befor the install and looked perfect to the naked eye anyway.


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[fz4k98]

When it is working correctly, how far off the floor does the pedal travel before the clutch begins to lightly engage?

I had a twin disk setup that was dragging and not fully disengaging over time. The two disks ended up being warped in relation to the center hub spline. This resulted in the disks wobbling and using up the gap that is present when the pedal is pushed. Everything looked fine but the issue could only be found by measuring.

Also, did you lightly grease the input shaft? I have seen improved clutch operation by applying a light amount of grease to the splines. just a light coating worked in, not enough to have it fly off and onto the disks.

[Randy V.B.]

Originally Posted by fz4k98

When it is working correctly, how far off the floor does the pedal travel before the clutch begins to lightly engage?

I had a twin disk setup that was dragging and not fully disengaging over time. The two disks ended up being warped in relation to the center hub spline. This resulted in the disks wobbling and using up the gap that is present when the pedal is pushed. Everything looked fine but the issue could only be found by measuring.

Also, did you lightly grease the input shaft? I have seen improved clutch operation by applying a light amount of grease to the splines. just a light coating worked in, not enough to have it fly off and onto the disks.

When everything is working properly it is about 3/4 the way out on the pedal I would say. Maybe a touch less than that. Which it is about 98% of the time it works properly.
I had the car out today and parked on a hill, I released the emergency brake and the weight of the car went onto the drivetrain. There was no way I could get the clutch to disengage even with a few pumps. I ended up ripping it out of gear and then starting the car. This is kind of making me believe that maybe my slave cylinder is not working with enough force?
And I didn't put anything on the spines besides a little bit of dry graphite spray. I always thought there should be something a little bit slippery on those spines but everybody always advised against it.


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[fz4k98]

It sounds like the clutch is binding on the input shaft. If it works sometimes but not under load the slave would only be an issue if weak. However, the slave should only be pushing against the pressure plate fingers. If it also has to overcome the clutch binding on the shaft it would then make the slave appear weak when it is actualy excess force issue.

My car is apart now and the shimming was in range of the .125 to .200 at .176. My clutch would begin to engage about 1/3 off the floor.

If the car is started in neutral on flat ground, it will shift normal, but as stated when under load will not? That would point toward the binding.

[Randy V.B.]

Originally Posted by fz4k98

It sounds like the clutch is binding on the input shaft. If it works sometimes but not under load the slave would only be an issue if weak. However, the slave should only be pushing against the pressure plate fingers. If it also has to overcome the clutch binding on the shaft it would then make the slave appear weak when it is actualy excess force issue.

My car is apart now and the shimming was in range of the .125 to .200 at .176. My clutch would begin to engage about 1/3 off the floor.

If the car is started in neutral on flat ground, it will shift normal, but as stated when under load will not? That would point toward the binding.

That is exactly what it's doing, under normal circumstances on level ground or if the engine is running everything is perfect but when there is a strain on the discs they seem to be binding for some reason, either on the spline or I have it shimmed wrong. I had the car on the hoist tonight and when I get someone to push the clutch in both desks have plenty of wiggle room. I'm going to try to reach in there with feeler gauges and see how much they're actually is. There's not much room to look in there besides those bottom vents. Regardless I guess it needs to come apart I'm just hoping for some magical thing to happen so I don't have to lol.


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[Randy V.B.]

The splines look really rough in the pics but you can barely feel them with your fingers. Opinions?


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[FasNuf]

Definately looks like you might have found your issue.

[Randy V.B.]

Originally Posted by FasNuf

Definately looks like you might have found your issue.

The car only has 45000km on it. Hard to beleave that shaft is that bad


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[fz4k98]

The wear on the shaft should only be in the area that the clutch disks ride on. If the splines look the same the entire length, the issue will most likely be in the clutch disk splines being worn. If the clutch has a lot of play on the shaft it would bind. See if you can find a different clutch disk and check it on the shaft to see if it is tighter than your current one.