VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Clutch throw out arm

Greetings
I put a new clutch and pressure plate in my 1940 Chevy pickup today and noticed there was no adjustment available on the clutch pedal. The throw out arm seems to be too low on the ball. It looks as though there should be a neoprene bushing over the ball but such a thing is not listed in the parts book. What is the spring supposed to do? Mine is hanging loose on the neck of the ball. Something is apparently missing or installed incorrectly.
Help!

The spring which I think you are referring to is the ball retainer spring. it clips into the throw out lever which has a groove machined to accept the spring.

www.fillingstation.com sells them.
clutch ball spring

So, the ball is actually supposed to rest on the spring instead of the back of the housing?

Or, is the retainer spring supposed to hold the arm on the ball?

YES, it holds it on the ball.

The ball is placed into the clutch fork, and then the spring is inserted to hold the ball into the fork. The whole assembly is then fitted to the clutch bell housing by screwing the ball into the thread and tightening.

Any ideas on why I have no clutch adjustment?

The ball is a pivot ,and the fork may be lifting out of the pivot when you depress the pedal , and pivoting against the bell housing. When you secure the ball into the fork , I think you will remedy the problem.

It appears to me that the ball on my truck is not correct. If it were even 1/2" taller I would have some adjustment to the clutch. Also, there is no place in the fork to insert the spring. If the adjustment nut is screwed all the way up tight on the linkage, I think the clutch will work. It did with the old clutch.

With these old vehicles it is never safe to assume that what is on the vehicle is correct to the vehicle. Even though I have owned the truck for 35 yrs and new the truck from way before then, still, stuff happens.

The only part in the 1950 part book which I could find that is different for a truck for 1940 models is the clutch fork. so maybe you have a passenger fork installed instead of the truck one.
The ball itself is the same. I could not find a 1940 adjusting rod to suit a 1940 truck, the parts book only has 1940 pass listed.
The throw out bearing assembly is also the same as the passenger
unit.

The only adjusting rod listed for 1940 models was also listed as pass models only.

Is this what your clutch fork looks like?

Commercial clutch fork

AHA,

I hope these pictures might clear some things up for you. They are of a 1941-48 passenger car clutch throw out arm. The arm is 10 and 1/4 inches long.

Good luck, Mike

I'm sorry, I've moved on to other projects. I just repainted my wheels and mounted radial tires. I am convinced that my throwout arm is incorrect. It may be possible to take the ball out and install a washer under the ball to provide more lift. Otherwise I'll have to look for a correct arm. The pictures are a great help. I couldn't figure out how the spring worked.

I hope to pull it out tomorrow.

Does anybody know where the jack was stored on these trucks?

The clutch adjustment on my truck is a threaded rod with a hook on the end. The hook attaches to the pedal. The arm listed on ebay may be what is in my truck. I remember the hole on the end. It is where the clutch pedal return spring fits. I have a 235 motor that has a thick washer under the ball.

If the arm on my truck is correct, then there is something installed wrong but the whole linkage is very simple. I need a higher fulcrum.

OK I mulled this question over in my sleep and figured it out, I think. I struggle with dimensional problems. I knew I needed more fulcrum to solve my problem but realized the problem was reversed in my application. Once the ball is trapped inside its hole this will limit its travel in the center therefore giving greater movement to each end, or in my case, the one end as the other is captured by the throwout race. This should provide the needed room for adjustment. Now I can't wait till daylight to check it out. Thanks for all your help!
Allen

Hi AHa,

It is surprising what a good night's sleep does for problem solving. Good luck today, and keep us posted on your results.

Mike

Oh the joys of working on antiques! Ok, after my honey do list was accomplished I tackled the truck. The clutch throwout arm is not easy to take off in the truck. Once I got it out I tried to reinstall the retainer spring and of course it broke. None of the local parts houses have a listing for one so I put it back on without the clip. While I had it loose in the housing I tried several scenarios to try and ascertain where my problem was. I would either need a taller throwout bearing or a taller ball to get the clutch adjustment that should be according to the pieces I have. The ball I have just barely fits while you are attempting to reassemble, a taller ball is not a possibility. Therefore, the only conclusion I can come to is that the original throwout bearing was more than 2" high. I added one heavy washer under the ball and this brought my pedal up to where it ought to disengage. 2 washers would be better. By the way, my throwout arm is the same as the one listed on ebay. There is a threaded rod with the end fashioned into a hook that goes through the larger hole at the end. The hook locks into a hook on the end of the pedal and there is about 2" of thread on the rod. In order to get the clutch to disengage I have to thread the nuts all the way up on the threaded rod, leaving no room whatsoever for adjustment. The throwout arm cannot get off of the ball even without the clip because there is no room for play. I wonder if there could be enough wear in the arm to cause this?

Can you post a picture of your T.O. bearing? from the bottom is OK.

The throw out bearing is right at 2" tall

That is a good thought about wear. Have you checked the wear on the fork end of the throw out lever where it contacts into the groove on the throw out bearing assembly. Maybe compare this end to the picture of the NOS one on Ebay.

I have seen many of the rods with the hook end having lots of wear. I have built the area up with my welder and ground it back to round with good success. I'm not saying that fixing that would solve all your problems but I have found that a few little things end up making a big problem.

Don is right, a little wear in multiple places can well lead to a major problem.
Tony

I am thinking the wear is my major problem. The hook is worn considerably. Also, I remembered that I had a shop manual. There is a picture of this part of the linkage and the nut is very close to the bottom. This makes me think there was never a lot of adjustment to start with. Also, the shop manual instructs grease to be put in the groove with the arm. The instructions with the new throwout bearings said nothing about adding any grease.

BTW, I had an exhaust leak that I wanted to stop but ended up breaking one ear off of the exhaust manifold this afternoon. We are having loads of fun. Ha!

Tonyw
Can you inform me of the correct location for storing the jack on your truck?

My truck didnt have any tools when I got it so I cannot give you any real indication in that regard though behind the seat would be my guess.
Tony