Clutch troubles!!!
- Thread starter bobs409
- Start date
Bob
I have a GM Z bar for my 65 Chevelle that will soon become a four speed and took some measurements. The long arm that attaches to the rod going to the pedals measures 5 1/4 inches from the top of the tube to the center of the hole. The bottom arm measures 3 1/4 inches from the tube to the center of the hole. If the lengths are different it will make the pedal either harder of softer depending on which one is different. The other thought is that if the Z bar doesn't have some axial movement the engine moving may cause it to hang up during driving. A diaphragm pressure plate is normally pretty soft.
Bill
I have a GM Z bar for my 65 Chevelle that will soon become a four speed and took some measurements. The long arm that attaches to the rod going to the pedals measures 5 1/4 inches from the top of the tube to the center of the hole. The bottom arm measures 3 1/4 inches from the tube to the center of the hole. If the lengths are different it will make the pedal either harder of softer depending on which one is different. The other thought is that if the Z bar doesn't have some axial movement the engine moving may cause it to hang up during driving. A diaphragm pressure plate is normally pretty soft.
Bill
Hi Bob, I just remembered something when I saw the post about greasing the z-bar. The one I had in my '09 had a grease fitting for just that reason and also had grease seals on both ends.I do not remember if the bar was for Chevelle or '63 passenger. It was definitly a GM replacement though.
Bob: I had a problem, similar to yours, about 2 years ago, with my 64. I took my wife and my son, to get some ice cream at Guptills.
Maybe a 20 mile ride. After about 15 minutes, it became harder and harder to get in first gear.
On the way home, I had to shut the engine off, then shift into first gear. Taking off from a stop created all sorts of chatter. Outside the car, and inside the car.:eek: I had to keep my hand, on the stick, or it would pop out of gear.:eek: All, we could smell was clutch lining. Finally, made it home. Started backing up, and heard a load crack noise.
Barely, made it back in the garage. What I found, scared me. All the bell housing bolts, on the passenger side, were gone. There were two bolts, on the driver's side, holding the BH on. And they were ready to fall out.
After removing the tranny, it was obvious, how loose the bell housing was. After I removed the bell housing, pressure plate and disc, I found a 2 inch piece of metal, that broke off the disc. Don't know, why bell housing bolts loosened up. After replacing the clutch parts, I put blue loktite on the BH bolts, this time.
Maybe a 20 mile ride. After about 15 minutes, it became harder and harder to get in first gear. On the way home, I had to shut the engine off, then shift into first gear. Taking off from a stop created all sorts of chatter. Outside the car, and inside the car.:eek: I had to keep my hand, on the stick, or it would pop out of gear.:eek: All, we could smell was clutch lining. Finally, made it home. Started backing up, and heard a load crack noise. Barely, made it back in the garage. What I found, scared me. All the bell housing bolts, on the passenger side, were gone. There were two bolts, on the driver's side, holding the BH on. And they were ready to fall out. After removing the tranny, it was obvious, how loose the bell housing was. After I removed the bell housing, pressure plate and disc, I found a 2 inch piece of metal, that broke off the disc. Don't know, why bell housing bolts loosened up. After replacing the clutch parts, I put blue loktite on the BH bolts, this time.
Well that only took 4 hours!
I wasn't able to remove the Z bar from the car without a major tear down but I was able to lift it up enough to get the broken ball stud out and put the new one in.
I had a Z-bar from a Chevy truck in my stash so I used the ball stud from that. Should be OEM.
Clutch pedal feels just like it did when I first put this together so hopefully things will stay good this time. Won't get to test drive until at least Monday due to rain.
BTW, this repro z bar had the grease fitting so I'm good there.
I wasn't able to remove the Z bar from the car without a major tear down but I was able to lift it up enough to get the broken ball stud out and put the new one in.
I had a Z-bar from a Chevy truck in my stash so I used the ball stud from that. Should be OEM.
Clutch pedal feels just like it did when I first put this together so hopefully things will stay good this time. Won't get to test drive until at least Monday due to rain.
BTW, this repro z bar had the grease fitting so I'm good there.
Been a long time, but is it possible to flip or turn the "z" bar over so the short arm is being used from the clutch pedal and the long arm to the clutch, or vise versa.? It seems I had one that was hard to push and one that was easy both in 58's and both with 11" taxi cab clutch and pressure plates. Just a thought.
Ray, I don't think this one could be flipped. The way it is now, the longer arm is at the top going to the clutch pedal so I guess that would be the best way to have it anyhow.
Maybe this particular pressure plate just has more spring pressure than the one in my truck. They are both Duralast brand. Maybe the truck has a better design of the rod layout. It is a '71 so maybe they made improvements from 66 to 71.
Bob
Maybe this particular pressure plate just has more spring pressure than the one in my truck. They are both Duralast brand. Maybe the truck has a better design of the rod layout. It is a '71 so maybe they made improvements from 66 to 71.
Bob
Bill,
I'll take some measurements next time it's on the rack but I think this one is about the same to guess. I did today's work all on the floor like the good old days so it's not on the lift right now.
:
Bob
I'll take some measurements next time it's on the rack but I think this one is about the same to guess. I did today's work all on the floor like the good old days so it's not on the lift right now.
:Bob
Actually I did but no good news to report.
At first, clutch was perfect! I went a mile in one direction, came back and went about mile the other direction. I noticed a bit harder to get into and through the gears by that point. Pulled in driveway and couldn't get into first again! Had to shut it off to get into 1st to get into garage. And that's where it sat since.
A quick look shows the z bar looked ok again. I welded a tab of metal on the frame bracket when I replaced the broke part so the ball stud couldn't ride up out of the slot so I know the problem is not that.
I hope to get back to it today. I'm really starting to miss my automatic.
At first, clutch was perfect! I went a mile in one direction, came back and went about mile the other direction. I noticed a bit harder to get into and through the gears by that point. Pulled in driveway and couldn't get into first again!
Had to shut it off to get into 1st to get into garage. And that's where it sat since. A quick look shows the z bar looked ok again. I welded a tab of metal on the frame bracket when I replaced the broke part so the ball stud couldn't ride up out of the slot so I know the problem is not that.
I hope to get back to it today. I'm really starting to miss my automatic.
Same thing all over again. Today I adjusted the clutch more and the pedal felt great. Went for about a mile and started noticing harder to shift and less pedal. Got so bad, I had to shut it off to get into 1st and actually drive it home like that! I couldn't even shift it out of 1st. Luckily I was close to home. Clutch pedal to the floor and it feels like the clutch is fully released, car just keeps pulling. This was the worst yet.
As far as I'm concerned, I have NO choice but to pull the trans and check the pressure plate. It has to be the problem. Whatever could be wrong with my made in Mexico Duralast clutch set?:
I had someone work the clutch while I watched and the z bar and rods are moving as they should so it's not them.
It seems like as soon as it gets hot, I lose the clutch. I had a full pedal at first, now you can push the pedal about 1/3 or more with no action.
While it's still hot, I got under and tried to crank the clutch rod out to get a good pedal again. I couldn't get a good pedal no matter how much I adjusted it.
Does any of this make sense? Can heat affect a pressure plate this way???
As far as I'm concerned, I have NO choice but to pull the trans and check the pressure plate. It has to be the problem. Whatever could be wrong with my made in Mexico Duralast clutch set?
: I had someone work the clutch while I watched and the z bar and rods are moving as they should so it's not them.
It seems like as soon as it gets hot, I lose the clutch. I had a full pedal at first, now you can push the pedal about 1/3 or more with no action.
While it's still hot, I got under and tried to crank the clutch rod out to get a good pedal again. I couldn't get a good pedal no matter how much I adjusted it.
Does any of this make sense? Can heat affect a pressure plate this way???
clutch
Bob, Several years ago I had a simular problem, finger type clutch (Sheffer) the pivot shaft had broken on one of the fingers. It would release when cold, but the hotter it got the harder it was to shift. Only two of the finger was trying to release, part of the disk was still in contact with the flywheel. Could be - maybe
W Head
59 El Camino 348-3,2s
59 Impala 409-2,4s
Bob, Several years ago I had a simular problem, finger type clutch (Sheffer) the pivot shaft had broken on one of the fingers. It would release when cold, but the hotter it got the harder it was to shift. Only two of the finger was trying to release, part of the disk was still in contact with the flywheel. Could be - maybe
W Head
59 El Camino 348-3,2s
59 Impala 409-2,4s
I had the other ball stud break. The one that threads into the block. I almost posted this because I had the same symptoms, but when you said that you adjusted it out twice, I thought that it must be something else . Mine broke off in the block before I could adjust it. There just wasn't that much play in the breaking stud to adjust before it gave way..
Funny, I had told Phil Reed my broken stud story from 1964 about a month ago when I visited his shop. It's come up twice in a month.
John
Funny, I had told Phil Reed my broken stud story from 1964 about a month ago when I visited his shop. It's come up twice in a month.
John
Bob,you are right,the problem has to be the pressure plate.I seem to remember running into hard pedal due to the diaphram having issues:eek
ont remember it being heat related thoIt's been several[many]years since I have done much clutch work,but I do remember having issues with these units caused by the clutch being adjusted in such a way as to "overcenter" the diaphram.What I used to do [takes 2 people] was to adjust the clutch so that you has .032 distance between the disc and flywheel with the clutch pedal on the floor.This also solved the problem with the clutch pedal sticking to the floor during a "speedshift"[any other old farts remember those].When you pull the trans.,look at the area where t.o.bearing rides.Are all the fingers even?If NOT then the diaphram has issues:?Best of luck,Don
ont remember it being heat related thoIt's been several[many]years since I have done much clutch work,but I do remember having issues with these units caused by the clutch being adjusted in such a way as to "overcenter" the diaphram.What I used to do [takes 2 people] was to adjust the clutch so that you has .032 distance between the disc and flywheel with the clutch pedal on the floor.This also solved the problem with the clutch pedal sticking to the floor during a "speedshift"[any other old farts remember those].When you pull the trans.,look at the area where t.o.bearing rides.Are all the fingers even?If NOT then the diaphram has issues:?Best of luck,DonBob
If the clutch rod is moving to where it should release the disc I would say you could have a bad clutch/pressure plate. The other thing I would suspect could be the problem is the pilot bushing. Brass grows with heat and if the bushing is too tight on the input shaft that could make it even tighter when the engine has run which means the shaft would spin with the engine even if the clutch is not touching.
Bill
If the clutch rod is moving to where it should release the disc I would say you could have a bad clutch/pressure plate. The other thing I would suspect could be the problem is the pilot bushing. Brass grows with heat and if the bushing is too tight on the input shaft that could make it even tighter when the engine has run which means the shaft would spin with the engine even if the clutch is not touching.
Bill
I really don't know what else to try except to check that pressure plate.
I think tomorrow I'm going to go for it.
If I find broken or bent parts, I'll know I have it figured out. If I find nothing, your going to hear me screaming from PA!
I can deal with fixing problems but what gets me is when you can't find the problem to fix.
Thanks for all the advice, it does help...
Bob
I think tomorrow I'm going to go for it.
If I find broken or bent parts, I'll know I have it figured out. If I find nothing, your going to hear me screaming from PA!
I can deal with fixing problems but what gets me is when you can't find the problem to fix.
Thanks for all the advice, it does help...
Bob
Ya know, maybe I better replace that pilot bushing while I'm in there. I got a new one with the clutch set. I don't think it's my problem but ya never know.
How the heck do I get it out anyway? It's been in there since 1963!
How the heck do I get it out anyway? It's been in there since 1963!
Pack the bushing hole with grease. Grind down a bolt or a piece of steel rod to fit into the hole and pound away with a hammer !! Hydraulic pressure will push it out.