VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Clutch Problem

1937 MD--I'm getting a consistent clutch "grabbing" on initial take off in 1st gear and shifting down into 2nd gear. I had the pressure plate/flywheel resurfaced and new clutch disk--I've adjusted it from lots of clutch play to very tight with no improvement. I probably have less that 25 miles on the rebuild--I'm wondering if it's time to try the old trick of placing the car next to a tree and let out the clutch in gear to burn off machine burrs or imperfections.

THRASHER.

My 2 cents...grin. I don't think that'a a great idea. Somethings wrong. Did all the springs and band go in place correctly? Is there anything like oil or grease on the clutch/flywheel surface? The "old trick " sounds like it could tear something up. But on the other hand...mine chatters,so what do I know?...smiles

Thrasher,

Dang! That beats all! Don't it?

Is it grabbing or chattering? Not the same thing.
Does it call for a pilot bearing? New one installed?
New clutch throw-out (release) bearing?
Was the clutch disc a proper one for the year and model?
Are the transmission and bell housing bolts tight? Were the mating surfaces clean of foreign particles?
Do you know how to drive a stick shift?
Are you using a gentle but positive touch on clutch release?
Can the missus drive it without the grabbing? Or is it just you?
Do you even have a suitable tree way up there in SD? Oh, yeah? What kind?

Charlie

Steve ...What do you mean by "MINE CHATTERS"????????ED

Chatter...shimmy and shake for a second or two

Grab...sudden lunge forward for a second or two

Bang or Boom...something broke !!

I bought the CHATTER kit that was on ebay that was suppose to be a "fix it" for old chevys. A vintage box and two rods that were attached to the rear motor mounts and the other end to the transmission support. First of all it didn't fit and I never sent it back. Next, I think I need a new clutch even if it doesn't slip.

I would jusr try slipping the clutch for a brief time every once and a while and see if it helps.

I had all kinds of stuff with my clutch. It grabbed, it chattered, it was no fun to drive. I fixed the entire problem with new motor mounts, the front one under the harmonic balancer and the two rear ones on the bell housing. I did it by using some large blocks of wood placed on the oil pan rail of the engine to slightly raise the engine with my floor jack so I could remove the old rear ones and install new ones. I basically did the same on the front. It took a little of time and care, but I got it done. Be sure the fan has enough room to clear when you raise the engine, also the exhaust may need to be loosened and anything else that could get hurt in the process. Just think it through and you can do it!
The results were wonderful. No more clutch problems of any kind. By the way, this is a 1937 1/2 ton pickup and they were the ORIGINAL motor mounts. What a difference! Also tried the clutch chatter gizmo thing that I bought on ebaY. Didn't come close to working!

I have had the same experiance with the 52 and up cars with the side engine mounts and the transmission mount. I did have a problem with the transmission mount on the cross member, It had gotten so out of line that I couldn't get the socket on the 5/8" bolt heads to pull the two bolts and remove the old worn out transmission mount. I looked the situation over and decided to pull the cross member, replace the 53 transmission with a 54 and also to pull the master cylinder and rebuild it. It turned into a two day job instead of a 1/2 day job. No more clutch chatter!

I had a similar problem with my 1 Ton when the transmission was leaking a little on to the clutch. I found that if I parked it overnight with a board holding the clutch pedal down, the next day the problem would be gone for the first twenty minutes of driving. I removed the transmission and had it rebuilt. There was nothing really bad about the transmission except for the leak.

Here's some more--I rebuilt the transmission, new throw-out bearing, new pilot bearning, new rear motor mounts. Since 1937 was a one-off year and I couldn't get a new clutch disk I had one custom made which could be part of the problem. I didn't replace the old transmission mount which is likely a problem as well as the front motor mount. I also remember the machinist who resurfaced the pressure plate found a hair-line crack that went about a half inch from one of the bolt holes--couldn't fix it and wasn't sure if it was going to be a problem or not.

Woops--I meant the flywheel, not pressure plate.

Hair line cracks in the flywheel...See them all the time...Nothing to worry about...Superficial...

I'd be concerned with the motor and tranny mounts....

engine mounts new & adjusted properly - not to tight - not to loose ?

are the springs to stiff ( think pickup grade ) in the clutch plate ?

my 39 loosened up & the chatter smoothed out over time & use .

just thin'in . frank

I wonder if maybe this grabby thing is just a fresh clutch plate your not used too...? I don't know...

Can you check if the flywheel lining face is parrallel to the flywheel/crankshaft flange mounting face?

That's rarely anything to worry about. The mounting surface sits on the table while grinding or against the faceplate while turning in a lathe, so unless the machinist didn't clean or check for burrs before mounting, things will be okie-dokey.

How are the splines on the transmission input shaft? And does the disc mate well?

this gets my vote . frank

#244918 gets my vote . frank

....unless the flange on the crankshaft isn't in line with the flywheel and the face of the bell housing is not in line with the clutch shaft on the transmission and the transmission needs to be shimmed to prevent runout of the flywheel surface. These surfaces should be checked with a runout gauge mounted on the bell housing face, as per instructions in the Chevrolet Shop Manual.

I just ordered a transmission mount repair kit from Chevy's of the 40's--I have a feeling that might be the solution--at least the easiest at this point and something that needs to be done. As for trees here in South Dakota Charlie, we have more than a few--I remember as a kid seeing WW2/Korean Vets getting together on a Saturday morning, using stout branches of a cottonwood tree to hook a pulley/chain to pull an engine or two before the next Stock Car race--certainly the good o'l days. I'll let you know in a week or so how the rebuilt mount worked.

Update on my clutch problem--I noticed when first starting the engine and depress the clutch pedal there is a sound coming from the bell-housing that sounds like the fan rubbing against the radiator almost like a screech. The sound goes away as things warm-up but I'm still getting a rough release as I start off in first gear and again on down-shifting to second from third. Could this be related to a broken spring on the pressure plate which causes an uneven amount of pressure on the clutch disk?

could it be a dry ( no grease-lube ) throwout bearing ? frank

Broken springs don't make noise....and certainly not noise that goes away after warm-up...check your "throw-out" bearing...

Hello Thrasher,

Did you add lube to the fill tube of the release bearing. The manual I have for my '37 MD says to add 160w lube to the release bearing when they make noise and not again until it makes noise again.