Projects 1950 Caddy 331 With Hydramatic Tranny

Hi guys...looking for some imput on these 4 speed caddy hydramatics...I bought a 1950, 331 with the hydramatic attached, and was wondering if anybody is running one of these tranny's in a model A....I'm hoping to find a 30-31 model A pickup, and use the caddy in it...So...is it worth going thru the tranny when I do the motor?..or just swapping over to something else...thanks

 

There's a lot of threads about the hydramatics, as well as a social group dedicated to them.
They are beefy transmissions, big and heavy. But also pretty bulletproof...even in stock form.
Rebuilding the hydro (if it needs it) will be a little more pricey than rebuilding a PG, since there are only a few builders around the country still up to the task. Of course, with a little time and research, you can tear into it yourself. The parts to rebuild them are fairly readily available.
I'd run the hydro, but I'm biased myself (have one in the 34, and another 2 or 3 in the garage).

Find the group here: Hydro Tech

 

Thanks for the info..I'd love to run this tranny, and your right, it may not need rebuilding as it was running the day it was removed from the ambulance, but I guess thats everybodys story..right?....I guess I didnt look close enough when I was searching the HAMB for info on these....I just wanna make sure that before I sink any money in it, that they are good tranny's..I think keeping the orig tranny and motor together is always good in a hot rod model A if you can...

 

I had an early Hydro behind an Olds 394 in a '50 Ford panel years ago, and am presently running a Cad 331 with a '50? hydro behind it in a Model A roadster and will attest that they are a good tranny. Heavy, and parts are kind of expensive if you need them but really tough and they're not all that hard to work on. I'd go for it...

 

Get a '52-'55 dual range. '50 hydro won't go into reverse without complete stop, can't be held in 3rd gear manually, fills thru the floor ... same money will build either trans, so do a later one. The '50 86 series trans may have some value with the professional car folks.
God, how I miss Yorgatron ....

 

These are good old transmissions. 302GMC named most of the not so good features of the early single range hydros. Other than the reverse being mechanical in nature, the transmission is still strong and lasts forever. You really have to abuse these things to break them.

 

Are these the same transmissions that GMC used in their 50's pickups?

 

Yes. The transmission body is the same. I am not sure if the torus differed in size between Caddy and GMC.

 

We offer other options for the extended bell Caddys and Oldsmobiles ....... 350/400 turbo as well as a 700r4 ..... For the same potential cost as the rebuild of the hydro....

 

Thats interesting..I'll keep u guys in mind when I finally get into that project...just have to find a truck with good bones first

 

Doesn't the Hydramatic have a real low 1st gear?

 

They are pretty low geared and they are really fucking heavy, too. My first car was a 49 Olds with the trans out of it, me and a couple of friends changed it in the driveway without the use of any jacks. Damn that sucker weighed a ton, I swear. My first experience working on cars and I was only 15 years old, too young and dumb to know any better. I have no excuses for my addiction now, over 56 years later.

 

They are low geared. Mine winds out on the highway trying to keep up with everyone doing 65/70. Mine is a 1950 331 and 4 speed hydramatic single range. I'd certainly opt for the dual range ones if they're geared for the highway a little better.

 

Mine is a 31 model A roadster with a 49 Cadillac engine and a 51 olds Hydramatic (short, with a flat pan). It's heavy, but very tough. Rear end is a 3:27 ratio. Low gear is very low, like granny low in a truck 4 speed. The transmission automatically starts out in second unless the shift lever is in the low position.

 

They all have a 1:1 ratio in 4th gear so your highway rpms are going to be determined by the rear end ratio. The low 1st gear ratio is to make up for having the hydraulic coupling instead of a torque converter.

 

I had one - 331 Caddy with a hydro - in a 33 Plymouth. I would get busy. Strong. I would recommend it if it's affordable. Like the guys said, it will cost a little extra to have it rebuild because of some special tools and experience.


Dave.

 

Get a good manual and have at is they are not that tuff to build.

 

I bought a '48 Cadillac flathead engine a few years ago and it had a hydramatic with it. I'll bet it weighs as much as the engine as it has a cast iron body. Have gone through the engine but the tranny sits in the corner of the shop. Oil doesn't smell burned but is it worth the effort to work on one that has to be a very early hydramatic and are parts available?

 

I had one up in till 5 years ago.
I loved the low first gear but that was all. It's shortcomings outweigh all the pluses.
Today, I would opt for a later overdrive automatic. So many more advantaged and parts are easier to locate.
Technology rules for this item.