VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1940 transmission interchangeability question

I'm experiencing major issues with 2nd gear. Symptoms are major grinding noises and vibration. In order to drive the car I have to avoid 2nd and shift from first to third.
My questions are;
1. Besides 1940, what year transnissions will fit my vehicle.
2. Does anyone know where I can find a replacement transmission?

I think 1939 to 1948 passenger car synchro-mesh transmissions (steering column gearshift) are the same. Where to get a rebuilt one is going to be a challenge. ebay is listing rebuilt ones for $1,1000. Rebuilt Transmissions. You rarely see them for sale so this might be a good deal if the source is repeatable.

You may want to do a search of previous posts on transmission issues to decide if you would want to try to repair yours. A lot of the parts are still available.

When did you first notice a problem shifting into second? Do you know about double clutching? Do you have vacuum assist on your transmission?

Good luck, Mike

mike,

1941 through 1948 transmissions had the speedometer cable outlet moved forward a bit. i don't know if that is a problem for using one on a 1940 or not.

it seems that he has a bad gear when the gears for second are active. Well duh! But if the transmission was looked into it may be a simpler fix than one thinks.

i have a couple of gears from a 1940 (most of the internals fit right on up to 1955 or so. i'd be glad to help with a used part if he needed it.

Charlie

The 1939 "stuff" is completely different from 1940.
The 1941-1948 transmissions are the same. The 1940 trans. case is different because the Vacuum shift cylinder bolts onto the U joint ball flange in 1940 and bolts to the case in 1941-1948. The 1941-48 can be used in a 1940 if bolts are installed in the case mounting holes to prevent the gear oil from being thrown out.

Part of your problem is the syncronizer for 2nd gear is worn out and the cluster gear damaged as well.

Thanks for your responses.... The 2nd gear issue developed late fall last year. Early last year my original 216 was replaced with a 1955 235 truck engine (after the 216 died on me) I used my original 1940 bellhousing/trans and gave away the 1955 truck trans and bellhousing....
Would the 1955 2nd gear internal truck transmission parts be interchangeable with the defective 2nd gear1940 parts?

The 2nd speed gear (and most other parts) fit from 1940-early 1953. In late 1953 several improvements were made and in 1955 almost all gears were different.
I would suspect you are going to need more than just 2nd gear. It should be removed and inspected before you do any thing.

Here are a sampling of past post, accessed through our SEARCH process, on your transmission concerns.

Transmission Info

Mysterious Synchro Assembly

41 Transmuission Removal

Good luck, Mike
P.S. Sychronizer rings are still available from ebay and the Filling Station.

Thanks once again for the responses, search links and good advice. I agree that I need to pull and inspect
trans. It will be another learning experince. I will try to make an effort to post on my progress.

Another thing to look at before pulling the transmission.

Double clutching and grinding

Good luck, Mike

Hey Guys !.....haven`t been on the forum for awhile ....but re reading the posts on the double clutching that Mike linked , got me revved up for more inspection of my `40. Will be returning to NC in a few weeks and get the old girl down off the stands and fired up after the warm winter you all had in that area( Charlie comes to mind ) . I have an extra tranny that was gifted to me by a local friend that I may get into for fun and learning . FUN fun fun ....summer is near !! David

I was at first dead against swapping out the trans in my 41 project car. But after reading the problems guys were having such as yours and not liking the way the shifting set up was done back then.

I went ahead and swapped it out , lucky that I had majority of the parts just lying around and found out I could still use my clutch, pressure plate and flywheel ect.

It was easier than I thought and still kept it 3 on the tree with OG column shifter

I had a chance to take it for a little spin up and down the road. And I can tell it is gonna out perform the OG stuff big time.

E41,

i may have missed something. What are you speaking of when you say 'swapping out"? Swapping out to what? The 41 transmission to another kind? I be plum puzzled.

Thanks,
Charlie

me too....?

The 1940 Master Deluxe frame that I am GIVING away includes a transmission..

https://pittsburgh.craigslist.org/pts/6086737291.html

Yes change it out, I used a trans from a late 50's early 60's Chevy.

I know this isn't the answer you were looking for but for me this drive train up grade is day and night in performance

Edmunds41 Offline
Shade Tree Mechanic

Registered: 05/10/11
Posts: 32
Loc: Bakersfield Ca.

Are you Tom Edmunds from So.Cal. MC?

Ray W

I have located 41-48 transmission which I will be picking up in Madison WI on Saturday. Several questions
1. Do I need the transmission tails shaft assy? I assume that I do, but it wasn't shown in sellers pictures.
2. Are there different mounting points on the newer trans. It looks like there may be a plate below newer unit that might bolt to the frame crossmember.
3. Can I use my 40 vacuum unit on 1941 trans if mounting position is different. Assume I need to plug holes you mentioned so not clear if my V.A.unit would mount up.
Thanks

If the trans. is from a 1941-1948 all you need to do is use your 1940 mounting for the vac. cylinder and plug the holes in the case. The vac. cyl. fits 1940-1948models.
The trans. mounts in the same manner.

Just a warning. Before you install the "new" transmission it should be disassembled and inspected. Short of doing that and seeing it has been moved and placed in different positions I would suggest flushing it out because any metal parts stuck to the bottom of the case will have been floating around. In this case kerosene would cut the grease and loosen in stuck in the grease particles. After the kerosene I would pour in a quart of cheap motor oil and finnaly trans. gear oil. For that I would suggest a 85W-140 for several reasons.

PS- the rear extenions are the same for either.
Also add a few ounces of gear oil - remove speedo gear fitting to do so. This will lubricate the U joint until the oil in the case makes its way back there.

Thanks for your prompt reply.I'm in the process of pulling the old trans. The rubber boot for the vac. assist appears to have disintegrated over the years. It always seemed to work rather well with the exception of not being able to shift unless the motor was running so it must be somewhat out of adjustment..

It is normal to work hard when the engine is not runnning. That is because there is no engine vacuum to provie the assist. New boots are available from the Filling Station..

No I'm just an everyday Edmund..

I picked up the new (used) transmission last Saturday and finally had a chance to unpack it and look at it last night. At this point I have mixed emotions about what I bought for $150.00
1. There is a lot of side to side play on the input shaft. I assume I will need a front bearing.
2. Transmission appears to leak from various places including front shaft and side holes where vacuum Assist mounts. There are no bolts in those holes and vac. Assist was apparently removed and "upgraded" shift linkage installed with the longer shift bracket mounted on the trans.
3. On the bench, it appears to shift well with three distinct detent/positions noted including two forward gears and neutral, so I feel good about that.
4. I can'tell seem to get it in reverse...possibly because I don'the know how to use the smaller lever in conjunction with the large lever. The small lever doesn'the appear to do anything. What is the procedure to bench test for reverse?

I hope to pull my old trans in the next day or so. That project is more difficult because it is still locked in 2nd gearight making it difficult to access trunion/u joint bolts. I have shift linkage disconnected and am planning on putting a vice grip on old trans. in order to get it unlocked. Any tips are appreciated.

Also, I read somewhere to brace/support the torque tube before pulling trans. This was not noted in the service manual. Does torque tube need Support?

All suggestions are welcome.

[quote=

I hope to pull my old trans in the next day or so. That project is more difficult because it is still locked in 2nd gearight making it difficult to access trunion/u joint bolts. I have shift linkage disconnected and am planning on putting a vice grip on old trans. in order to get it unlocked. Any tips are appreciated.

All suggestions are welcome. [/quote]

Have the back wheels jacked up off the ground and the car well blocked. With key off depress starter to turn engine over which will turn the trunion/universal joint. You might be able to do the same by removing flywheel cover and putting a socket with breaker bar on one of the flywheel bolts to turn engine/trans/universal over slowly. Yes block the torque tube

dick

It is normal for the front shaft to flop around in the front bearing retainer.
Seeing it is a 1941 trans use the 1940 vac. Cyl. bracket and plug the bolt holes in the case.
If laying around in various positions grease would have leaked out of many locations.