4 speed not able to get in any gear

[RussT Plymouths]

this just starting happening at the end of last cruise season. four speed manual. can shift gears no problem with car not running. car running not moving can't get it into gear. if car is moving no problem shifting.

This has happened to me, the only way to get it in gear, was to start it in gear. What I found was a cracked clutch release lever inside the clutch cover. The other two levers were still good, the cracked one was only doing a partial release. You might be able to check for this by having someone press the clutch pedal while you measure the gap between the flywheel and pressure plate in several locations around the flywheel. You will need to manually rotate the engine. All should be the same.

Remember that it usually will take more effort to release a spinning clutch, centrifugal forces of the moving parts can add to the pressure plate. Meaning a cracked lever may bend more while spinning, and release less, dragging the clutch plate.

You haven't mentioned what style of clutch you have. I've heard of diaphragm clutches also developing cracks.

this problem seemed to come out of nowhere. had that setup in car since 2019

Yep. Left for work, no issues. As I was driving through the gate at work, problem showed up.

 

[mac]

This has happened to me, the only way to get it in gear, was to start it in gear. What I found was a cracked clutch release lever inside the clutch cover. The other two levers were still good, the cracked one was only doing a partial release. You might be able to check for this by having someone press the clutch pedal while you measure the gap between the flywheel and pressure plate in several locations around the flywheel. You will need to manually rotate the engine. All should be the same.

Remember that it usually will take more effort to release a spinning clutch, centrifugal forces of the moving parts can add to the pressure plate. Meaning a cracked lever may bend more while spinning, and release less, dragging the clutch plate.

You haven't mentioned what style of clutch you have. I've heard of diaphragm clutches also developing cracks.


Yep. Left for work, no issues. As I was driving through the gate at work, problem showed up.

it is a centerforce dual friction clutch (diaphram style). i (with the help of my daughter) attempted to do and extreme clutch adjustment. throw out bearing is making contact with fingers on clutch. what is seem to notice is once i get to about 3/32 of a gap, i can not get the gap to increase. so i think that it might be a problem with the clutch release levers. shift fork looks good, throw out bearing feels smooth, a z bar is steady (no flex or deflection). clutch will still spin freely but can't check that with car running obviously. but same result is with car not running can shift with no problem. when car is running and have put a load on clutch to move, can not get it to shift into gear from a stop. if i am rolling car trans will shift. as soon as i shut engine off car can shift. so my guess is there is some kind of load from the clutch being made that is just enough internally so i can't shift. make sense?

 

[mac]

right now with all this issues, if i decide to get a new clutch which brand should i try. car is 1969 road runner 440 6bbl. engine was built to hopefully make 550 hp at crank ( no dyno to back that up )

 

[mac]

removed transmission for the 3rd time and removed the clutch assembly. it looks practically brand new. don't drive that much each season and it has 4 seasons on it, so maybe a little less than a 1000 miles. pilot bushing shows no sign of excessive wear. did a little searching for others having issues with the dual friction setup and there were a few that stated they were not able to get a proper clutch pedal adjustment. i hate throwing money at problems but i might just have to. thinking of trying a Mcleod setup instead.

 

[gto64gto]

Don't know if this will help. 30-35 years ago, I had a 64 GTO. I bought a new Hays flywheel and diagram hat. Trans wouldn't shift. I tried everything (lakewood scatter shield) really made it aggravating. I pulled the trans out 10 times trying everything I could think of. Different throw out bearings, adjustments, ect. Turned out to be a BAD new Hays clutch--last thing I would ever thought of. They replaced it and no problems after that.

 

[AR67GTX]

removed transmission for the 3rd time and removed the clutch assembly. it looks practically brand new. don't drive that much each season and it has 4 seasons on it, so maybe a little less than a 1000 miles. pilot bushing shows no sign of excessive wear. did a little searching for others having issues with the dual friction setup and there were a few that stated they were not able to get a proper clutch pedal adjustment. i hate throwing money at problems but i might just have to. thinking of trying a Mcleod setup instead.

Kind of a mystery but here is something you might try out of curiosity if you have a hydraulic press. Pull your flywheel off and assemble the clutch and disc to it. Set it in the press with the flywheel down. First of all just check the finger height, clutch assembled and static. They should all be within a very few thousands. Then place your TO Bearing on top and a suitable plate for the ram to press on. Measure the stack height unloaded and then crank the TO bearing down until you get .060” clearance between the clutch disc and the pressure plate at a selected point. Measure the stack height loaded. Then measure the gap between the flywheel surface and the pressure plate at 1/4 or 1/8 points around the circumference and compare. Most likely there will be some variance but it should be within 6 or 7 thousands for the most part. If you start finding .020 and higher differences the clutch probably has some degree of chattering/shuddering. If you find a place where there is still pressure plate contact with the disc you will have found why it probably isn't releasing completely to allow moving between gears.

If the stack height shows the TO bearing is having to be pressed down excessively to release the disc by .060” then this could be the problem too. What is excessive? Not sure of a definitely answer but in working with the hydraulic clutch in my ERA Cobra, the slave cylinder had a little over 1” maximum range - maybe 1-1/16”, can’t remember exactly. But if I wasn’t getting clutch release with 3/4” to 7/8” +/- stroke (+ some free play) I was going to have issues. Possibly someone else here knows what TO bearing stroke the clutch pedal, x-bar linkage, and fork amount to on our Mopars. In general I think pedal travel in them is pretty generous.

One of the mechanics that frequents the C2/C3 forums ( pi have an old Corvette too) came up with this testing and the ran a bunch of different manufacturer clutches through it, measuring how much depression was needed to achieve disc release. Old Corvettes have a confined foot box and limited clutch pedal swing and thus they frequently have issues with clutches that won’t depress enough to release. In his testing, McLeod clutches were the best for short release. I don’t remember specifically about Centerforce but I think they were generally in an acceptable range. Some of the rebuilder units like LUX were pretty erratic and took a lot of stroke.

I found a new pressure plate that I once installed in my Corvette and chattered badly was bad with the above testing. Just bolting it down to the flywheel indicated the finger height was not very even and stroking the unit to .060” clear left the pressure plate with a very uneven gap to the flywheel.

Might be of interest.

 

[AR67GTX]

Don't know if this will help. 30-35 years ago, I had a 64 GTO. I bought a new Hays flywheel and diagram hat. Trans wouldn't shift. I tried everything (lakewood scatter shield) really made it aggravating. I pulled the trans out 10 times trying everything I could think of. Different throw out bearings, adjustments, ect. Turned out to be a BAD new Hays clutch--last thing I would ever thought of. They replaced it and no problems after that.

I once bought a new Hays 30lb flywheel for my Corvette that was so warped I ended up having to have it surfaced twice to get it flat. That was nearly 30 years ago - can’t remember why I didn’t return it. Maybe I ran it first. No more Hays products.

 

[mac]

Kind of a mystery but here is something you might try out of curiosity if you have a hydraulic press. Pull your flywheel off and assemble the clutch and disc to it. Set it in the press with the flywheel down. First of all just check the finger height, clutch assembled and static. They should all be within a very few thousands. Then place your TO Bearing on top and a suitable plate for the ram to press on. Measure the stack height unloaded and then crank the TO bearing down until you get .060” clearance between the clutch disc and the pressure plate at a selected point. Measure the stack height loaded. Then measure the gap between the flywheel surface and the pressure plate at 1/4 or 1/8 points around the circumference and compare. Most likely there will be some variance but it should be within 6 or 7 thousands for the most part. If you start finding .020 and higher differences the clutch probably has some degree of chattering/shuddering. If you find a place where there is still pressure plate contact with the disc you will have found why it probably isn't releasing completely to allow moving between gears.

If the stack height shows the TO bearing is having to be pressed down excessively to release the disc by .060” then this could be the problem too. What is excessive? Not sure of a definitely answer but in working with the hydraulic clutch in my ERA Cobra, the slave cylinder had a little over 1” maximum range - maybe 1-1/16”, can’t remember exactly. But if I wasn’t getting clutch release with 3/4” to 7/8” +/- stroke (+ some free play) I was going to have issues. Possibly someone else here knows what TO bearing stroke the clutch pedal, x-bar linkage, and fork amount to on our Mopars. In general I think pedal travel in them is pretty generous.

One of the mechanics that frequents the C2/C3 forums ( pi have an old Corvette too) came up with this testing and the ran a bunch of different manufacturer clutches through it, measuring how much depression was needed to achieve disc release. Old Corvettes have a confined foot box and limited clutch pedal swing and thus they frequently have issues with clutches that won’t depress enough to release. In his testing, McLeod clutches were the best for short release. I don’t remember specifically about Centerforce but I think they were generally in an acceptable range. Some of the rebuilder units like LUX were pretty erratic and took a lot of stroke.

I found a new pressure plate that I once installed in my Corvette and chattered badly was bad with the above testing. Just bolting it down to the flywheel indicated the finger height was not very even and stroking the unit to .060” clear left the pressure plate with a very uneven gap to the flywheel.

Might be of interest.

i could probably get this done. it would be nice to see if it would confirm something causing this. the only, what i think is a problem, is i have a few days to order and get free pickup from the transmission shop when i am at Carlisle.

 

[mac]

anyone have anything to say about Mcleod clutches/

 

[mac]

I once bought a new Hays 30lb flywheel for my Corvette that was so warped I ended up having to have it surfaced twice to get it flat. That was nearly 30 years ago - can’t remember why I didn’t return it. Maybe I ran it first. No more Hays products.

the flywheel was replaced when the clutch was changed. old flywheel looked like it had some heat checking.

 

[mac]

UPDATE. i preordered a new clutch kit from Mcleod. had to pick up in Carlisle. installed today and problem is fixed. must have been a problem with the centerforce pressure plate not able to move evenly and release clutch. thanks all for the help.

 

[AR67GTX]

Thanks for letting us know. Back on the road again!