1938 Pontiac Transmission replacement

[Tony38]

  I'm currently working on a 38 Pontiac with the 223 flat head 6 and a 3 speed on the column. The transmission is completely locked up, and I'm struggling to find a replacement or even a conversion trans for it. I bought the conversion manual and either I'm blind or just overlooking something, I don't see a comparable. I do plan on taking the trans apart and checking everything under the instructions of the service manual.  With that being said I'm pretty green when it comes to that style of trans, but hey gotta try. If anyone knows of a replacement trans or even something that would work from another model, I'd be greatly appreciative. If its a floor shift trans I can accommodate and fabricate no problems. 

 

Thank you, Tony

[TerryB]

From a transmission book printed in 1942

 

[TerryB]

More

 

[TerryB]

Diagnostics

 

 

[Tony38]

Thank you TerryB, looks like I've got a lot of studying to and a lot of searching to do. I really appreciate the help.

 

 

 

[junkyardjeff]

38 with a column shift ?,I thought it came out in 39.

[wayne sheldon]

Column shift? Column shifting mechanisms used to be famous for wearing out a bit, and slipping into a "no-man's-land" in effect locking the transmission into some combination of gears.

Many years ago, I had a couple old Chevrolets that did that a few times. Once, limping around with a dead starter, the transmission linkage slipped out of place, and I could not take it out of first gear. Middle of the night, couldn't shift into neutral to keep the engine running, fortunately I was quick enough to not lock it into a combination of first and second, I drove a couple blocks stuck in first gear to a small hill, where I set the brake, and killed the engine. Then I went under the hood, and pushed the linkage back into place. On the hill, I could roll forward and pop the clutch to restart the car, and continued on my way. A couple days later, I rebuilt the starter.

It is just as simple for the transmission to lock into two gears, and then you don't move an inch, even pushing the clutch pedal!

 

Could it be that simple?

Edited September 19, 2021 by wayne sheldon
I hate leaving typos! (see edit history)

[Bloo]

If it is not just linkage problems as wayne sheldon mentioned, it can probably be rebuilt. If it has not already become clear from TerryB's posts, the Pontiac transmissions from late 1935 forward are of the same architecture as the Buick Special, and probably quite a few internal parts interchange.

 

The whole transmission is not the same as Buick, and most likely not the same as any other year Pontiac either thanks to that very early column shift.

 

I'm betting it is just in 2 gears at the same time as in wayne sheldon's post.

 

 

[Robert G. Smits]

2 hours ago, junkyardjeff said:

38 with a column shift ?,I thought it came out in 39.

I don't know about Pontiac but Cadillac got column shift in 38

[1939_Buick]

2 minutes ago, Robert G. Smits said:

I don't know about Pontiac but Cadillac got column shift in 38

And Buick in 1939

[Frank DuVal]

I agree that this lockup could be  the transmission in two gears at once. People back in the 60s and 79s were used to jumping out and fiddling with the linkage under the hood to get the transmission back into one gear to leave the traffic light! Just remember to set the parking brake, or the vehicle can run away or over you.

[mike6024]

Looks like '38 column shift are common among Pontiacs.

 

 

First one is an 8 cylinder, and second a six

 

Make: Pontiac

Model: Other

Type: Sedan

Trim: Deluxe

Year: 1938

Mileage: 45,757

VIN: 8DA7305

Color: Gray

Engine size: Straight 8

Number of cylinders: 8

Fuel: Gasoline

Transmission: Manual

Drive type: RWD

Interior color: Tan

Vehicle Title: Clear

 

Make: Pontiac

Model: Other

Type: 4 door sedan

Trim: 38-2619DA

Year: 1938

Mileage: 46,810

VIN: To be furnished

Color: Black (repaint over Phantom Gray)

Engine size: 6 cylinder

Number of cylinders: 6

Transmission: 3 speed manual (three on the tree)

Drive type: RWD

Interior color: Gray/Brown original; New brown seat covers.

[mike6024]

There were few mechanical changes for 1938.  The most notable was the Safety Shift Gear Control, a $10 option on any ’38 model.  It was advertised as the first column-mounted gearshift for the low-priced field; a necessary distinction since Cadillac also offered a column-mounted gearshift this year.  It should also be noted that all 1938 Oldsmobiles, plus the Buick Special, could be ordered with the Automatic Safety Transmission; this semi-automatic unit also had the selector lever mounted on the steering column.  Buicks and Oldsmobiles fitted with the conventional standard transmission retained the floor mounted shift lever.

 

[mike6024]

There is a big difference between the transmission being locked up, and the shifter mechanism being jammed. It's easy for the shifter to get jammed, especially if out of adjustment.

[TerryB]

More on gearshift adjustment.  This is from my book on 1935-42 transmissions and rear axles that I have for sale for $10 (hint,hint😀).

 

[John348]

21 hours ago, junkyardjeff said:

38 with a column shift ?,I thought it came out in 39.

 

I think Jeff is correct, my father had a 39 Pontiac, I think was standard on all Pontiacs in 39 and an option in 38

Edited September 20, 2021 by John348 (see edit history)

[Fireball8man]

Buick made the Automatic Safety Transmission for Oldsmobile in 1937, 1938, and 1939 and sold it off to Oldsmobile shortly after and in 1940 the Hydromatic was the result.  The self-shifter was offered only as an option for the 1938 Buick Special series 40 models.  The gearbox selector regarding the AST and the Buick self-shifter is altogether used with a semi-automatic transmission and its components are completely different to that of a regular column shift used with a manual transmission (apples and oranges).

[Robert G. Smits]

On 9/19/2021 at 4:05 PM, Tony38 said:

I'm currently working on a 38 Pontiac with the 223 flat head 6 and a 3 speed on the column.

I would check my vin/serial numbers as column shift didn't come out in Pontiac until 1939 except for the "Safety Shift" option in 38.  You may have an early 39 that was registered as a 38.  Just a thought

[rocketraider]

22 hours ago, Fireball8man said:

 

Can someone explain the AST selector quadrant? Looks like putting it in R with engine off locked the transmission as a HydraMatic does. What are the two arrows in F position? Low and High?

 

AST has always intrigued me but I've never gotten a good explanation of its operation.

[1939_Buick]

30 minutes ago, rocketraider said:

Can someone explain the AST selector quadrant? Looks like putting it in R with engine off locked the transmission as a HydraMatic does. What are the two arrows in F position? Low and High?

 

AST has always intrigued me but I've never gotten a good explanation of its operation.

A post by the late Dave Corbin, who owned a 1938 Buick self shifter.  Ausume

Link---> https://forums.aaca.org/topic/97645-1938-buick-special-self-shifter/?tab=comments#comment-420689
 

Quote

 

Important driving tip: After you start the engine, let it run for about 30 seconds in neutral with the clutch in so the transmision builds oil pressure internally. Put the clutch in and count slowly to 10 (about 10 seconds). Move the shift lever to F1 or R depending on which way you want to go. DO NOT GRIND THE LITTLE FRONT GEAR BOX! Patience is a great virtue here! Use this procedure each time you push the clutch pedal. If you're going forward, move to F2 at about 15 MPH without using the clutch. If you do this , you should use all 4 forward speeds.

As you're comimg to a stop, push the clutch in at about 8 MPH and use the brakes for the rest.

As you start forward, feed it a little gas and let in on the clutch about like you would with a standard floor shift. Take it very easy at first (many of that first 50 miles were in a big shopping center parking lot when it was closed.) You'll get the "hang" of it quickly.

 

{off topic post}

Edited September 21, 2021 by 1939_Buick (see edit history)

[AWISE]

Tony38,  I just replaced the transmission in a 37 Pontiac that worked good and have another for parts.

If you did any things or someone to talk to,   Andy  Wise   andygarage@comcast.net   302-245-7276

[Bloo]

The posts about AST are interesting, but I think you will find that "safety shift" in 1938 Pontiacs is just an optional column shifter for a 3 speed manual transmission, as was suggested earlier in this thread.

 

I think that you will also find that the 3 speed transmission uses a setup that had a single arm on the transmission to move gears, and some other device (a cable?) to move the gate. If I am not mistaken, Buick also did this for a while.

 

All Pontiac transmissions of that era are directly related to Buick Special 3 speed manual transmissions, but are not quite exactly the same.

 

If the whole transmission is not completely full of rust, or run dry of oil, it is probably stuck in 2 gears at the same time due to linkage problems.