The Stovebolt Site Forums The Shop Area Driveline 1954 3-speed transmission casting code

Does anyone know the casting code for a 1954 Chevrolet truck 3-speed transmission?

The casting code might be different from 1953 and earlier, but there were only minor changes in 1954.

Another way to ask this question is: does anyone know how to ID a 1954 truck 3-speed (enclosed drive-shaft) from earlier 3-speeds?

Here is minimal information on the ID for a 1954 Muncie 3 speed transmission

Thanks,

Tim, I have the 3 speed out of my truck if a picture would help you out. There is transmission number decoding info in the front of the service manual or the restoration packet I believe.

Thanks, Greg,

The link I gave above is the information in the Restoration Pack. It is a date casting code: Plant Month Day (no year)?

Here is the information I could find in the 1954 Shop Manual. It states where to find the code; but, it does not indicate what the code is?

Of course, I could be missing something (I am getting older/slower every day).

What is the 1954 code that I should be looking for (in order to distinguish a 54 from an earlier transmission)?

OK...I give. It looks like your plant, month, day is what is given. http://chevy.oldcarmanualproject.com/chevyresto/5409.htm

Tim, do you have a different link.
It's showing Bumpers, Lights & Horn.

Also, don't know if this will help, but....

It looks like the change was in 1953.
1953 1st design & 1953 2nd design.
1954 is the 2nd design.

However, the same 3 speed Transmission Case,
with casting 591615, was used thru 1954.
http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0372.htm

The difference between the 1st design & 2nd design
looks to be internal.

Here are some of them:

Main drive gear
http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0402.htm

Clutch, gear & also the
Retainer, Synchro ring
http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0404.htm

Gear, 2nd speed
http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0405.htm


There was also a new 3 speed, heavy duty transmission in 1954. (not torque tube)

Tom,

Thanks for the information.

Here is the Shop Manual link - sorry.

http://chevy.oldcarmanualproject.com/shop/1954truck/54ctsm0000.html

(I have corrected the link above, thanks, again).

I think the only differences between 1954 and earlier is briefly described in the first paragraph under Three-Speed Transmission:
http://www.1954advance-design.com/Documents/EngineeringFeatures/slides/orig_Page56.html

I am looking to buy a 1954 transmission - I'd like to be able to ID it, if possible.

Thanks,

If there is anyone that would know for sure is,
John Dobbins at Northwest Transmission Parts
Gene from Restoration Hydramatics turned me on to John, Boat load of info.
They have five warehouses full of automatic and standard shift transmission parts.

Tim, the first paragraph only refers to
carburizing and shot peened.
According to the MPC they also made
other minor changes on the inside.

The 54 shop manual refers to location.
http://chevy.oldcarmanualproject.com/shop/1954truck/54ctsm000.html

And as you know, the 54 Resto Pack only lists the Plant, Month, Day.

To ID the transmission use the case casting code listed in my previous post.

Then, open up the tranny and check the 2nd speed gear.
If it has 4 slots then you have a 53.2 or a 54.

Then check the other parts using the MPC.

So it is possible to ID but....
a lot of work and maybe many transmissions,
since the same case casting # from 48-54.

The heavy duty 3 speed has the year on the outside of the case,
the regular 3 & 4 speeds do not.
http://chevy.oldcarmanualproject.com/chevyresto/54057.htm

Happy Hunting!

Thank you, Tom

Greg_H has a 54 3-speed and he pretty sure it is original
I have an original 3-speed in my garage (somewhere).

We will both compare our codes (but, for mine, I will not have access until late April or May).

Hi Tim,

This is my first try at stovebolt, wow what a resource!

In 1975 I bought a 1954 1st series GMC 1/2 ton in Elkhart Kansas for $120.00. Well, finally I have it close to being restored accept for finding the right 3-speed bell housing to mate up to my rebuilt 1951 GMC 270 engine. Anyway, If it helps, I am 99% sure I have the original 1954 3-speed and would be glad to go over to the shop and get #s off it or take photos. Just let me know.

forgot to sign:
Jed

Hello, Jed,

I would appreciate seeing any codes you find. No need to post photos of the codes. Just post them here.

I do not think that photos of the transmission would help me ID the year.

Thanks very much,

Jed,

When you say you are looking for a bell-housing, are you referring to the clutch housing or the cover for the u-joint. Most likely you want a clutch assembly bell housing.

Either way, post a Parts Wanted ad in the Swap Meet.

If you are looking for a 3-speed clutch housing, maybe someone will comment on GMC and Chev truck housings being the same. Also, the 3-speed housing has a shift-linkage post on it (that post is not on the 4-speed housing).

Tim,
My 1955 1st series GMC 1/2 ton 3-speed with torque tube has the following number on the transmission casting. C20G and 591615. Again I bought the truck in Elkhart Kansas in 1974, I assume it is the original transmission.

I still have my Dad's 51 Chevy 1 ton panel truck but it is in terrible shape. I might use the frame and engine and convert it to a I ton pick up cause I found a decent cab. Now I need to find the nine ft bed and running boards.

Good luck,
Jed

I just went through this with rebuilding of my muncie 3 sp. in my 53. Seems GM was making some progress with their auto and light pickup transmissions. Up to and including 52 the transmissions had a single row of needle bearings in the clutch gear. These transmissions were known to pop out of high gear easy when they could/would get some miles on them. In 53 the first design included a double row of needle bearings in the clutch gear, 24 of little ones and 14 of the bigger needle bearings on the inboard side of the clutch gear. The second design increased the diameter of the clutch gear ,but still retained the two rows of needle bearings. Also believe there was a main shaft change to accommodate the second row of needle bearings, but not sure.