Serious Clutch issue

I've got a 1947 CJ2a. It has a 231 V6 and a Ford NP435 4 speed. Recently my pressure plate broke. For 4 years the clutch has worked very well, very little adjustment needed. It has a 10.5" chevy pressure plate and a 10.5" Ford clutch. It has always been smooth. I am using the basic stock willys clutch linkage. I've just lengthened the cable from the rear pivot to the clutch Z-Bar.

Problem: When the clutch was adjusted enough to allow it to shift, the jeep would not move when the clutch was released. When adjusted to allow the jeep to move when released, you could only grind gears. These two settings were nearly the same.

I thought the pressure plate was bad, so I replaced it, the clutch, and throw out bearing. Put it back together and the same thing. Nothing has changed. When you depress the pedal, I can't "feel" the clutch disengaging. However, there is a significant amount of Z-Bar movement.

Can't anyone help?

Thanks,
Dave

 

Check your linkage for slop and wear, and watch the clutch arm and see how much it moves when someone else presses the clutch pedal.

 

What Jeepnut said. Sounds like you aren't getting enough linkage movement to fully disengage the clutch pressure plate when the pedal is depressed. Nickmil.

 

Yeah, check for clutch linkage wear. You might find something like this....



That'll leave you stranded in some bad places!

 

Unless you bring jpflat2a with you. He has a spare.

 

Not to hi-jack the thread - but after mine failed and Jim saved my butt I replaced that piece with this:



Back to the original topic - what jeepnut said.

 

hey bob, that looks like my clutch linkage. thad seems to have my old stuff too...

on topic though, i had an issue that was pretty much the same as yours and couldn't figure out what was going on. both ends of the shaft were where they were supposed to be to get the optimum lateral movement, but i couldn't get enough movement. the problem was solved by putting a washer under the pivot bolt to help the throwout bearing closer to the pressure plate. then i changed over to a new crossbar (mine was just about toast) and now have too much throw.

so i guess the moral of my story is check the holes in the cross-shaft to see if they're worn down a little bit. that will effect the overall movement at the clutch fork... after that it's all smoke and mirrors to get the right amount of movement.

 

I have replaced most of my stuff with what you suggested. The movement seems to be enough, but maybe it needs to be more. Does anyone know how much movement I should have?

I will assume this: When released, the clutch fork should be at complete rest (almost slightly loose). When depressed, it should move the throwout bearing into the pressure plate enough to disengage the the clutch, right?

When you talk about slop, do you mean 1/8" an inch more or less. Or are we talking about something more significant?

When assembled and the linkage disconnected, the clutch fork was just at complete rest. This looks and feels great. But I can't get it to release the clutch. I completely agree with the fact I am not getting enough travel, but what I can't understand is why has it all of a sudden decided not to work. Nothing has change since I designed it 4 years ago. This is very frustrating and I don't really have much of anyone to help me

I guess I'll keep looking it over and see if I missed something. I will also try adjusting the set up, so that the pivot points will allow for max travel.

Thanks for the help,
Dave

 

could your t/o fork be bent, or the fork pivot ball starting to push thru the fork?
thinking out loud

 

Also was the release bearing the same height as the original one?
Nickmil.

 

When the pressure plate "broke" what did it bend/brake. I had a pressure plate brake in my truck recently and after a grand in parts fixing everyting it bent I was up and running. It even messed up the hydraulic slave cylinder (yes I know you don't have one but I didn't think that would get hurt and it did) so I would check all the non-replaced parts for damage even slight bends may make a big difference.

 

The fork and pivot points appear to be fine. They are not bent and the pivot ball is in good condition. However, I'll go back through and check them again. I'm afraid I'll be pulling the motor multiple times, trying to get this right

The clutch place, Capital Clutch in Indianapolis, just said it was broke. Something about a spring inside I think. They didn't elaborate much.

I'm still worried that my problem is lack of travel, but that still doesn't explain why it is just now a problem. What happened over the last four years?????? This is very frustating, I get all worked up every time I think about it. I've re-built this jeep from the frame up three times and now this happens and I can't figure it out.

Thanks again for the help. I'm going to try to work on it again tonight. Hopefully I won't lose my temper and set fire to it.

Dave

 

Dave, step back and take a big breath and maybe a
did all the new components match up the same as the old ones?
were the p/plate fingers the same, same height? diaphragm p/plate?
based on your own testimony, something must have changed.
any chance the clutch cross shaft has been installed reversed? in other words, the levers welded on the shaft, could the throw change if you, by accident, installed it the other way?
the actual clutch pedal is keyed to the brake pedal/clutch pedal support shaft; is it okay and not spinning/loose on the shaft?
as mentioned earlier, the t/o brg; is it the same as what was removed?
the ball studs for the cross shaft; they are okay and the brackets that hold them are okay?

 

Did the problem begin immediatelyu after you replaced the pressure plate? I read above that you have already disassembled this again. Could the throw out bearing have been misaligned in the pivot?

 

There are several different length GM throw out bearings. This is a critical measurement. Check to make sure the new bearing has the same overall length as the old one. Actually, the bearing itself is the same, it's the collar that is pressed in that connects to the fork that has different lengths.

 

The throwout bearing is a little beefer than the one I took out. I would think this would be an issue if the fork couldn't come to a complete "rest". However, it does so the slightly thicker, heavier duty bearing isn't an issue. The collar is a little longer, but where the bar attaches is the same point. It doesn't appear to bottom out or anything like that. I will check this if/when I remove the motor again.

The keyed pivot bar is installed correctly and is not slipping. This is newer, but it was working before the issue.

The pivot balls are worn. But they were worn to start with.

The problem developed before I replaced the pressure plate. It has been a little hard to get out of 1st gear at times for a while now, but nothing too bad. No clutch slippage or gear grinding to speak of. It is possible that this has been slowly developing. I only drive the jeep once a month and it is used for wheeling then.

I recently entered it into a mud bog. Shortly after that it was toast. Everything was packed in mud because there was not guard. No amount adjustment worked. When I removed the clutch disc, it wasn't worn at all, some slight hot spots on the flywheel/pressure plate. So, when they told me the pressure plate was broke, I thought that was why I lost all my adjustment. I had full clutch, but no adjustment. If adjusted so I could shift, it wouldn't move.

I keep thinking it is a total throw issue. It's like it will not throw the bearing far enough to disengage the clutch and then return the rest state. I just don't understand why it is happened now? Maybe I was just getting by before and I didn't know any better. It was adjusted just right. I can say this, it never has had much adjustment.

Sorry, I'm starting to ramble. It's really hard to type everything I am thinking and make it make sense. I need to have a video conference call

I'll look at it tonight and see if I can figure anything out.

Thanks for the suggestions,
Dave

 

Just an update. I worked on the clutch this past weekend and got it adjusted well enough to not slip and allow me to shift. BUT it appears to be riding on the throughout bearing. The total throw of the clutch fork appears to be about 1/4" short of what it needs to be. When shifted from first to reverse the jeep wants to move just a little, like the clutch isn't completely disengaged.

I don't know what my next step is. I may have to change to a hydraulic clutch

Dave

 

I used the Wilwood setup with EXCELLENT results. If you get the right pedal ratio with your master cyl. the clutch feels like a new car it's so easy!
Do you have any cable in your linkage? My 67 had a cable from the linkage going to the fork. Kept stretching/binding up offroad, so I swapped it out.

 

No, there isn't a cable like the CJ5's had. It is more stock Willys than anything. I lengthed the rod from the rear pivot bar to the clutch fork.

What Wilwood setup did you use? How did it work with your clutch pedal?

Thanks,
Dave

 

I used the Wilwood pull slave and the master cyl. I welded a small bracket of my pedal (hanging pedals) and put the master high up on the firewall, which gave me a good pedal ratio. It is just as easy as a new rig. Much better when twisted up offroad as well!