The Stovebolt Site Forums The Shop Area Engine Shop clutch chattering while driving

I just got my 1955 2nd series truck running and it chatters when i give it the gas. The pedal engages right off the floor, I have a lot of free play. I looked at the clutch thickness and it looks fine. Is their and adjustment on the pressure plate? I dont have any oil leaks on the rear main seal; but it feels like the clutch is oiled. I tried adjusting the clutch today and I went the wrong direction and it wont go into gear. I will reverse the j Rod tomorrow. Anny help would make my wife really happy.

Are you saying the clutch is slipping under a load? If so it sounds like your pressure plate is bad and there are no adjustments on it.

When I took off the dust cover I noticed that their are some bolts inside the pressure plate, could these be some type of adjustments? Their not the bolts that hold the pressure plate to the flywheel.

if "the pedal engages right off the floor" the first thing you gotta do is get it properly adjusted b4 you think there's some problem, like Dave sez, no adjustment inside

Bill

NX Brad,

Those bolt are not field adjustable...as DAVE said, there are no adjustments in the clutch/PP area other than the external clutch adjustment you have already addressed.

Adjusting the clutch free play can sometimes become confusing. If can adjust the rod to obtain the required free play on the pedal, in the cab, then that's about all you can do. If things still slip, it's time for a replacement.

All you are doing when you adjust for pedal free play is making sure that the throwout bearing isn't running on the clutch fingers when the clutch is engaged. Other than that, the system either works or it doesn't. If it doesn't, it needs to be replaced.

Stuart

Thanks for your input I'm going out to adjust it in a little while. Could the clutch disc have oil or be slicked by sitting for 22 years? Iv,e been told to burn the clutch by slipping it while it is anchored down what do you think?

Brad,

I have always felt the friction material of the clutch was real thirsty! Give it some oil and it will soak it up. Once it is contaminated, it's pretty tough to burn it off/out. A cooked, crispy hard clutch face will slip too, so again, it's almost a replacement situation.

This is my two cents on the deal! You have nothing to loose by adjusting the clutch and then experimenting with it to see if you can make it better...have some fun.

Stuart

Try letting the clutch out all the way before giving it any gas if this only happens when you are getting rolling. Another trick that has worked for me is to start out in second, but I don't know why it works. Clutch chatter can occur when the motor mounts are bad. I never heard a slipping clutch chatter.

I too am at a loss as to what the problem is.
With the information given things just don't add up.

About starting in a higher gear, my clutch will actually chatter more. I usually start off in 3rd or 4th, but if I mistakenly start off in 6th the clutch chatters, or at least the dampener springs in the center of the disk act funny. This only while trying to release the clutch, if I go ahead and let it all the way out the engine try to die, but keeps going just under a normal idle, and no clutch chatter. I do have reasonably solid mounts, with about a 35" spread between the rear pair.

I would read your service manual and adjust the clutch peddle as it tells you. As the others have said, you can't actually adjust the clutch, only where the peddle and throwout bearing are in relation to the fingers on the pressure plate.

Check your timing and vacuum advance, I have an idea that I can't seem to put into words, but for some reason I think bad timing could cause the symptoms?

Grigg

I readjusted the clutch and the pedal feels better; but,it still slips when you give some throttle. It feels like the engine has too much torque. We all all know that's not the case. I did notice the the pivot ball was worn a lot,I can move the arm really easy. This should mean their is no pre-load on the pressure plate. I even tried burning the clutch but it still responded the same. I'm going to replace the clutch and plate with a kit. Who sells the kit at a good price? Thanks for getting me on the right path.

I forgot to add, Where can I get a new through-out arm and pivot ball?

I would think that LMC would carry that part. A GM dealership may also be of help. The clip used on the arm was used for over 30 years so I am betting the ball was too.

You will want to take a good look at your flywheel surface to make sure that it looks good.

Jim Carter and Classic Parts of America have rebuilt p-plates along with fork balls and many other clutch related parts.
LMC offers clutch kits.

It,s best to get a new clutch kit. The remans are inconsistent. I,ve been using Carquest lately & they have been very good. Soft & smooth. The other parts should be available at the specialty supliers. I,ve got a few of the retaining clips on hand & will mail you one if you want.

Thanks for the info I did notice the clip was wrapped around the ball and hanging out. Is the clip designed to snap around the ball? If so could that give me the false since of the ball and arm is warn out?

Clutch chatter can also be aggravated by bad engine mounts. I would replace the mounts while you are under there messing with the clutch.