Clutch pedal vibration during aggresive driving

[jpl572103]

I wanted to thank all of you who offered suggestions to my questions in the past. I've got the 66 Dart, slant with a Passon b body 833. I've got 300 miles on the transmission.
I installed a Luk 9" clutch with the standard mopar pressure plate, a brewers roller pilot bearing. Same bell/fork/zbar.

If I put max power to the engine while in 1st 2nd or 3rd, the clutch pedal has vibration,I feel it while shifting gears. It's in the clutch pedal not the shifter. And once I reach 4th , the vibration is still there. While cruising you can touch the pedal and feel the vibration. If I press and release the clutch pedal 1 time. 1 additional press and release, then all is back to normal. No vibration from the pedal.

The trans shifts perfect when driving normal.
I wanted to mention during the 300 miles, 4 maybe 5 times , after shifting into 3rd gear, It would not shift into 4th or any other gear. I could get N or 3rd only. Happened at a light. Had to take off in 3rd. Again it happened after I picked up my daughter, drove normal to her school. Parked for 10 minutes with engine off. Left the school, shifted 1st to 2nd to 3rd. Could not get 4th no matter what I tried. Could not get 2nd. Pulled over, turned car off, started car. Could get R and 3rd only. Then like a switch was turned on I had 1st. Has happened a few times after that. It won't go into gear except 3rd after going up or down from 3rd. And then it fixes itself while I fidget with pressing the clutch in and trying to move the shifter.

Open to suggestions please.

 

[dr dodge]

I had issues with a trash truck cheby 4 speed, doing similar, crazy stuff
it was the bearing between in/out shafts
it had (i think) too much play up and down, and some flattened rollers
changed those, and front/rear bearings, and the thing worked flawless after that

 

[jpl572103]

I hope its not internal trans issues.

 

[DC 340]

I wanted to thank all of you who offered suggestions to my questions in the past. I've got the 66 Dart, slant with a Passon b body 833. I've got 300 miles on the transmission.
I installed a Luk 9" clutch with the standard mopar pressure plate, a brewers roller pilot bearing. Same bell/fork/zbar.

If I put max power to the engine while in 1st 2nd or 3rd, the clutch pedal has vibration,I feel it while shifting gears. It's in the clutch pedal not the shifter. And once I reach 4th , the vibration is still there. While cruising you can touch the pedal and feel the vibration. If I press and release the clutch pedal 1 time. 1 additional press and release, then all is back to normal. No vibration from the pedal.

The trans shifts perfect when driving normal.
I wanted to mention during the 300 miles, 4 maybe 5 times , after shifting into 3rd gear, It would not shift into 4th or any other gear. I could get N or 3rd only. Happened at a light. Had to take off in 3rd. Again it happened after I picked up my daughter, drove normal to her school. Parked for 10 minutes with engine off. Left the school, shifted 1st to 2nd to 3rd. Could not get 4th no matter what I tried. Could not get 2nd. Pulled over, turned car off, started car. Could get R and 3rd only. Then like a switch was turned on I had 1st. Has happened a few times after that. It won't go into gear except 3rd after going up or down from 3rd. And then it fixes itself while I fidget with pressing the clutch in and trying to move the shifter.

Open to suggestions please.

Hi jpl, I used to live in Newport News. First, I don't understand how the clutch pedal can feel vibration unless the throw out bearing is riding the pressure plate fingers. I would check your free play. As far as the rest, I would first get under the car, align that shifter using the appropriate tool, and inspect the linkage connections.

 

[jpl572103]

Small world! what you are saying sounds logical. Thank you.

 

[Dan Brewer]

Sometimes when under heavy acceleration and the engine is trying to rotate in the mounts, shifter linkage can rub / touch the transmission crossmember / torsion bar crossmember in the car and rattle or vibrate the shifter but be completely fine under normal driving conditions. The same thing could happen with clutch linkage parts and transfer up into the clutch pedal into something you feel. Especially on cars that have been converted to manual trans where we might have some mis-matched parts. It's worth a look anyway.

 

[SixPaksRule]

Did you check and correct the concentricity of the bellhousing centerline to the crank centerline? The symptom you describe is what happens when they are out of line

 

[jpl572103]

Sometimes when under heavy acceleration and the engine is trying to rotate in the mounts, shifter linkage can rub / touch the transmission crossmember / torsion bar crossmember in the car and rattle or vibrate the shifter but be completely fine under normal driving conditions. The same thing could happen with clutch linkage parts and transfer up into the clutch pedal into something you feel. Especially on cars that have been converted to manual trans where we might have some mis-matched parts. It's worth a look anyway.

View attachment 1716548994

Thank you. I do plan to check that linkage. The exhaust installed is 2 1/2 and looks very close to the threaded clutch linkage where it attaches to the Z bar. Your picture calls it 6-24-1.

 

[jpl572103]

Did you check and correct the concentricity of the bellhousing centerline to the crank centerline? The symptom you describe is what happens when they are out of line

No. Same engine and bell, only thing replaced was clutch and transmission. Never crossed my mind to even bother with it due to no vibration issues with the 833od.

 

[jpl572103]

Sometimes when under heavy acceleration and the engine is trying to rotate in the mounts, shifter linkage can rub / touch the transmission crossmember / torsion bar crossmember in the car and rattle or vibrate the shifter but be completely fine under normal driving conditions. The same thing could happen with clutch linkage parts and transfer up into the clutch pedal into something you feel. Especially on cars that have been converted to manual trans where we might have some mis-matched parts. It's worth a look anyway.

View attachment 1716548994

I havent' figured out the pedal vibration yet, I did close up the free play on the fork to 1/2. It actually appears to be shifting into 1st 2nd better. And I found that by using muscle on the pedal makes all the difference. Just got done on a 15 minute drive. It's fun again. My question is about the slop between the z bar and shaft 6-52-1. Is there no retainer like the one coming from the push rod to the top of z bar? And is the free play-slop normal on the lower shaft to z bar? 6-52-1 shaft