VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 '37 Master Clutch Disc

I have reached the time when I need to take a look at the clutch assembly in my '37 Master coupe. The clutch does not slip but the engagement action is very quick and there is a slight shudder during engagement. Plus the transmission is leaking especially at the ball on the u-joint housing. I have been accumulating parts in anticipation of this project and have quite a few.

I have a used clutch disc that has the brand name Perfection Gear Company on it. Based on what I can find they were in Harvey, IL which is south of Chicago on I80.

I got this thinking that I would have it relined before I started the project to hopefully reduce the time that the car was not drivable. Today I found the disc (a miracle in itself) and started looking closely at the condition. It is much better condition than I remember. I now wonder if I should plan to use it as is.

The 1937 specifications state that the disc lining thickness is 0.122 - 0.128 ". I took multiple measurements of the lining thickness on both faces. It measures between 0.115" to 0.121". The liming face has no physical damage such as pieces missing or gouges or burn marks. The slots in the lining material are all very uniform. On both sides the minimum depth of lining to the rivets heads is 0.050".

I also expect that there is asbestos in the lining so it will perform more like the original. The hub shows no wear on the splines and the springs are in good condition.

Am I crazy to consider using it as is?

Rusty,
Don't give me the opportunity to make obvious comments and expect total accuracy. In this case I will attempt it. Yes, you are definitely crazy. So are nearly all the rest of old Chevy & GMC enthusiasts. But, in that case crazy is not necessarily bad. We provide a service to humanity others are not capable or interested.

I know that is not an appropriate response but had to do it. From your description I say go for it. May not prove to be all you hope but nothing likely is! A 1/2 a loaf is still bread and will taste good toasted, plain with butter or jelly. Now peanut butter WOW. Not on the clutch plate as it will tend to make it slip.

As for the asbestos don't worry unless shipping to OZ. Like many other modern "hazards" it is not all it is cracked up to be.

Rusty, I would suggest that, while you have things apart, you consider replacing the rear main bearing seal also. Quicker - than - normal action, accompanied by a shuddering are the earmarks of a clutch plate becoming compromised by oil hitting it. It would be a shame if you installed your new-old clutch plate, only to find that after a few months of use it is behaving like the old one. Just a thought!!

A 1937 does not have a rear main bearing seal That came along in 1940.

Hi Kaygee,

You probably are not aware that the '37 216 does not have a rear main seal. There is a slinger disc on the crankshaft that deflects oil into a circular cavity machined in the block and rear main bearing cap. The oil collected in that cavity drains back into the pan.

I have removed the lower flywheel cover and confirmed that there is no oil getting onto the clutch. I do have some slight leakage from the rear main bearing but it all stays on the front side of the flywheel. Some leakage is the nature of that design.

Hi Chipper,

Many thanks for the accurate and appropriate assessment of my situation on all counts! It aligns with the inputs I receive from another who resides here.

If I am having difficulty with a certain project or repair I will stop and take a short break. If she asks how things are going I often say "This so-and-so is about driving me crazy". Her polite response is" That is not a very long trip."

With respect to the actual clutch project, thanks for your inputs on my assessment. For now I do not plan to get the disc relined. My comment about asbestos was more focused on the fact that the disc might actually work a little better than some of today's materials used to reline clutches.

I have an NOS pressure plate and expect that I will need to get the flywheel surfaced. I am looking for the pivot pins to use with the NOS clutch lever arms, hub, and carbon throw-out bearing. I also expect that I might need to replace the clutch arm pivot.

I do have a complete '38 or '39 set-up (bellhousing, clutch arm, flywheel, disc, throw-out bearing & pressure plate) but I'm not sure I want to go that direction. I would also have to deal with a different starter.

The shudder may well be caused by the plates the facings are rivetted to, if the plate is solid 1 piece or multi wafer flattened out it will most likely shudder from the factory to scrap metal melting, if the multi wafer still has slight curve it should be very usable. The curved wafers act as a cushion to the clamping action.
Tony

Hi Rusty,

I read over the years that their are other things that can cause a shutter in our '37's.

Front motor mounts that have gone bad or became weak from a motor oil leak, the bell housing mounts are weak or the trans mount is bad or weak. The last item is a bit difficult to believe. Check the clearance of the differential and the saddles for excessive play.

I had replaced my original clutch with a '38 and liked the way it worked. I used the original starter with the '38 flywheel with no problems, but unlike you, I did not have a "38 bell housing. The difference in the location of the pivot ball for the fork was enough to off center the contact point at the throw bearing. This caused the throw out bearing internal bearings to fail, a couple of times. I have since gone back to the original clutch for that reason. If I can find a '38 bell housing I would probable convert back to it.

Hi Dave,

I appreciate your guidance on your conversion experience. I remember reading about that in one of my prior searches. I know that I have an advantage because I have a ”˜38 /”˜39 housing.

Just as an interesting point, LUK clutch offers a clutch kit (04-123) that they say will fit ”˜37 through ”˜53. If you look at the pictures you can easily see that it is not a lever arm clutch so I doubt if it would be a direct fit for a ”˜37. Is is a diaphragm style clutch. If I do decide to upgrade I am considering that kit.

The 38 is the first year for the "modern" diaphragm clutch spring which decreases foot pressure as you engage clutch. A significant design improvement over the 37. I'm thinking the input shaft on the 38 tranny is different to accommodate the different clutch and throughout bearing.

Thanks video ranger. I agree that ”˜38 was the first year for the diaphragm clutch. That is why I am surprised to see the LUK listing that states their kit will fit a ”˜37.

If you go back through the details in this thread as well as others the differences are noted. The transmission input shaft is the same. The bell housing and clutch are different to fit up with the rolling element throw out bearing. The flywheel is also different. It was only used for 2 years. In 1940 the rear of the crank shaft changed due to the new rear main seal and the 6 bolt flange on the crank.

I believe part of the difference is the gearbox front bearing retainer is different to accommodate the different thrust bearing.
Tony

Hi Tony,

I might be able to check that. I have another ”˜37 gear box as well as a later side shift gear box.

The only thing necessary to change is the front bearing retainer.
You will be surprised how the lighter pressue plate and flywheel makes the engine more peppie.

I am still debating if I will make the change. I have most of the '37 parts and am not sure I want to deal with changing the starter.