VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc '37 Master Deluxe Transmission trouble

Up until today, my car project has been mostly the acquisition of parts and reassembly. This morning, I started the car and went to put it into gear when there was a "BANG." Now it is stuck in gear, really stuck in gear. I removed the top of the transmission and can't see what is wrong, at least from the top. Nothing will move. I raised one rear wheel and tried to rock it back and forth to see if something would break loose, but no dice. It is locked up hard. I did look at the service manual, but I don't feel qualified to tear into the transmission. Chevy's of the 40's offers a rebuild service, but I was wondering if there is another source of rebuilders that I am not aware of. Prior to today's problem, it seemed to be working pretty good. I did have some gear whine in first gear, but 2nd and 3rd ran quiet. In order to make sure that the gears meshed without grinding, I could not hurry a shift, when down shifting, to avoid grinding the gears, I had to double clutch and accelerate the transmission a little while in neutral.

Any suggestions would be appreciated.

Thanks,

Rich

Not sure what is wrong but I am sure you could fix it not much to these transmissions and pretty easy to take out just take it out through the top they are pretty small.

Tim,

My reluctance to attack this transmission comes from reading the disassembly instructions in the service manual.

For example, I don't have the "special clutch gear and bearing puller J-937" or the "main shaft removing and replacing tool J-938."

While removal of the transmission from the car does not seem like it will be too difficuilt, actually getting into the unit may be a challange. Is the manual making it sound harder that it really is? Have you taken your's apart?

Thanks,

Rich

Rich
While you were turning the rear wheel what position was the gear selectors in? Have someone watch the gears, in nuetral the wheel should turn and some gears will turn but not the very front gear,if in gear you would need someone to depress the clutch to allow all the gears to turn.
If the wheel doesnt turn and the gearbox is at fault the gears will move and if not I would suspect the differential (final drive).
Tony

Rich yes I had mine apart and yes the manual makes it sound harder than it is. If you can fix them old radios this should not be to much of a challenge. I found the hardest part of the whole job was putting the u joint part back together.

Tony,

The "bang" happened just as I was starting the engine. I put in the clutch an pressed the starter and tried to pull the shifter into netural all at about the same time. The engine started and there was a noise that I am pretty sure came from the transmission. I was unable to move the shifter into any other position after the bang. With the engine running, I tried to let out the clutch, but as the clutch engaged, it was draging down the engine with no movement of the vehicle at all. I did think about raising both rear wheels to confirm that the problem was transmission and not differential. I will try that later today, but I am about 99% sure the problem is in the transmission.

Tim,

It is good to hear that the manual makes this sound harder than it is. I will give this a try. With today being Easter, business travel next week and the annual show for our radio club next Sunday, this will have to wait for a while.

How about parts? Once in a while, I see parts for sale on ebay, but as long as I am in there (assuming that I am clever enough to accomplish this task) I want to replace bearings and seals plus what ever may have caused the problem. I will check with the guy that I found in the Denver area with thousands of square feet of new parts, but that is the only other source I know of.

Thanks for the encouragement,

Rich

Yes you should be able to get some of the bearings locally there are some large needle bearings that will need to have grease on them to hold them in place when you assemble it. Not really any seals there is a slinger on the in put part of the trans but when I did mine I relaced the front bearing with a sealed unit then removed the seal part that faces the inside of the trans so it would get lubrcated from the trans oil and for some of the other parts yes ebay or Bruce Bugay. If I lived closer I would come and give ya a hand. Good luck and let us know what you find.

Tim,

You are only 90 minutes away. I have made the flight from MSP to DEN many times. I have relatives in western Wisconsin, about an hour east of MSP. Actually, I have enough frequent flier miles to send you a ticket, are you tempted?

Anyway, soon I will tear into this thing and see what I can find.

Rich

The 1937-39 had the straight cut gears in low and they make a lot of noise. If the transmission is working properly double clutching is not necessary. Will not go into first with car moving (yea, I know there are ways to do it), normal grinding of the gears will not harm the transmission. They were fairly rugged.
How do the shifter forks look (under cover)?...is the transmission jambed into two gears at once? With the cover off the 2nd speed gear should (rear top gear) should slide in and out of the syncro drum and the low gear should be free to slide on the outside of the drum.

Rich,
I have the J-933 "Clutch Gear Bearing Retainer Wrench" & the J-938 "Main Shaft Remover & Replacer". You're welcome to borrow them - they can be shipped out to you via Priority Mail in 3-days or so. All I'd ask is for you to pay the shipping costs, treat them as your own and return them when finished.
-Bob

Sounds good to me I have family in the Springs They own a business in denver and the Springs called Bulbs Plus

Because of other commitments, I will have to wait a couple of weekends before I tear into the transmission, but if I need help, I will holler.

Would a photo down into the top of the transmission give anyone any clues to the problem? If so, I will forward a photo.

Thanks,

Rich

Give it a try.

Also the under side of the cover.

Well, I took my transmission out of the car this afternoon.

Bad news is that I found one tooth missing off of the 4.395 Gear. I think this is second gear. This is the first gear inside of the case moving from the rear to the front. I also found a small piece of a steel pin inside of the transmission. I can send a photo if anyone wants to take a stab at confirming that this belongs inside of the transmission.

I mention this because when I bought the car, the top of the transmission was not installed. I cramed a long handled magnet down around the transmission trying to see if anything loose was in there, but did not find anything.

As near as I can tell this is the only damage. I can see just about every gear from the outside and I turned all of the gears looking for damage and only found the one missing tooth. However, there are several gears that I cannot see.

It looks like it takes a special tool to remove the rear retainer ring, or is there a trick to this?

At the top right rear of the transmission, opposite the location of the speedometer gear there is a hole with nothing mounted in it. What am I missing? If you look on page 101 of the Chev's of the 40 catalog, in the upper right of the page you can see the case and the location of the hole. Nothing is shown in this drawing.

Thanks,

Rich

Could the "Pin" be a needle bearing that maybe fell into the tran on a previous repair and got into the gear and messed it up? The hole on the trans I think was where they filled the trans at the factory and should have a plug in it.

The hole opposite of the speedometer-cable, is the negative battery pole connection. It shall be a ordinary screw in the hole. The hole is also used to fill gear oil in the u-joint when installing the transmission to the car.
I have just completely overhauled my 1937-39 transmission, I am familiar with all the parts, you can send me the photo of the unidentified object.

Bjorn

Bjorn,

Thanks, I am on a business trip now, but this weekend I will send you a photo of the missing part.

What is your level of experience with transmissions? Did you find this a difficuilt thing to take apart and reassemble?

Thanks,

Rich

Rich

I had never opened a transmission before I did this job, but it is not difficult, and you do not need much special tools.
There is a good description in the shop manual, (1937-1938-1939) and I also recommend the exploded drawings in the parts catalogue.

If you removed the transmission from the car by yourself, you can also do the overhaul by yourself, it is not difficult for a average mechanic when you have the instructions.

I changed all the parts inside the box, expect for the shifting yokes. You can buy the gears on ebay, they are not expensive, your damaged 2nd speed gear, you will find at about $50.

The most worn parts in my tranny were the countershaft axle and the countershaft gear (they were completely damaged, I waited to long to investigate the noises), but there were also wear damages on all the other gears.
If you are planning to use some of the parts again, it is important to read the shop manual instructions before you disassemble the gears, because some of the parts (clutch gear etc.) need to be marked and assempled in the same position as before.
For me, that was not important, since I built up the tranny with new, never used parts.

I am sure you can do this job alone or with a little help, I recommend you to disassemble and check all the parts when you have removed the transmissin from the car.

Bjorn

Bjorn,

Thanks for the information. I do have the service manual and the exploded parts diagram. The interior of my transmission looks great with the exception of the one damaged gear, which I already have. Chev's of the 40's also sells a rebuild kit which I will get. I have the front shaft out and the bearing looks like new and there is no play in it at all.

After reading the disassembly instructions, I did have some concern that I would not get it reassembled exactly as it should be, but I will give it a try.

Thanks for the encouragement,

Rich

I have been thinking more about your "BANG". As Chevgene writes, it could have been into two gears at the same time.
If you mounted the shifting cover with one of the shifting yokes in engaged position, this could have happened. I do not think a small foreign object or a missing tooth should make a total lock, as you described.
When you assemble your transmission and finally put the shifting cover on, be sure that both the shifter yokes are in the middle position (neutral).

Bjorn

After the removal of the transmission, I turned it upside down and gave it a good shake and nothing came out. I then went fishing with my magnet and got the broken gear tooth and the small pin (picture to follow.) The gears now turn freely.

I did drive the car about 20 miles over several weekends with no problems, so I think the shifter was installed properly. I may tear into it this weekend.

Thanks for the advice.

Rich

This morning I poured some solvent in the transmission to clean it out. While doing this I also sloshed it around and heard something loose in the case. I turned it upside down, gave it a lot of shaking and turned the gears at the same time.

A bent up interlock fell out. It has several deep tooth marks on it and it was missing a small pin on one end, the pin that I found previously. That solves the mystery of what caused the problem. I am guessing that this was done by someone at least two owners’ back. The guy I bought it from says he did nothing with the car, and I believe him.

From the exploded parts diagram, I can't really tell what gear the second speed gear meshes with, but it is likely that gear has some damage too.

Rich

When 2nd gear is selected it meshes with the rear gear of the counter shaft (cluster gear). That the big gear towards the bottom of the case.

I must admit that I was reluctant to disassemble my transmission. However, this morning I tore into it. I found that the only damage was to the second speed gear. I replaced the gear, needle bearings and the rear bearing, got it all back together and now have it mounted in the car. Getting the bolts back in the universal joint turned out to be the hardest part of the job, but that too is done. I have the parking brake bracket mounted and the torque tube reconnected. There are a few more bolts to put in, but I should be able to do a test drive tomorrow.

Somewhere I have seen how much gear lube to add after a rebuild, but can't find it now. Can someone help me with this?

All in all, this was a lot of work, but not too technically challenging. Everyone that said it was not as hard as the manual made it seem was correct.

Thanks to everyone for their encouragement and support.

Rich