The Stovebolt Site Forums The Shop Area Driveline Hydra-Matic anyone?

I'm sure it's just me, but none of Tim's links ever work for me.

Hello,

Here is a photo album of a 1955 Chevy 1st series 1/2 ton truck with a Hydra-Matic
https://picasaweb.google.com/106723428487424188160/1955ChevyTruckBlue?noredirect=1

The Hydra-Matic in this truck has a Cadillac center case which means it is pan fed. Pan fed means there is a tube attached to the tranny oil pan to check and fill tranny from engine compartment. There is no side smoke stack filler on a Cadillac case. All internal parts are the same. Just the case is different.

The rear tranny cross member is there but not used for tranny support.

As you can see it has open drive shaft.

Thanks

Hello,

1954 Frame spec, PDF page 90, Sheet page 129
http://www.gmheritagecenter.com/doc...hevrolet-Trucks/1954-Chevrolet-Truck.pdf

1955 Frame spec, PDF page 78, Sheet page 135
http://www.gmheritagecenter.com/doc...ucks/1955-Chevrolet-Truck-1st-Series.pdf

No change in frames from 1954 to 1955, but 3600 frame is beefer than 3100.

Go here click on Show to find above GM Vehicle Information Kits
http://www.gmheritagecenter.com/gm-heritage-archive/vehicle-information-kits.html

1955 1st with 4 speed manual, No rear tranny cross member
pic 1
pic 2
pic 3

I have some pics of 1954 with 4 manual tranny somewhere still looking.

Thanks

Hello,

Info from 1954 salesman data book.
1954 Chevrolet Truck Frames Specs
1954 Chevy Truck 3600, 3100 Frame comparisons Photo Drawing
Looks like there is a fairly big difference between the 3100 and the 3600 frames.

Thanks

Hello,

Took me awhile but I found the 1954 Chevrolet 1/2 ton truck with 4 speed tranny .
No tranny rear support cross member.
Enclosed drive shaft.
Picture Album

Bonus: Old UPS 1954 Chevrolet 1 ton Panel truck with 4 speed tranny.
2 piece Open drive shaft with center intermediate bearing.
pic 1
pic 2

Thanks

So, I went & wire brushed the rear end & found this stamped on it.
N K1224
Not sure if the "N" is part of it since its spaced kind like the way I typed it on here.

So what I'm trying to find out is what the gear ratio of this rear is.
I got it off of a 54 GMC Hydra-matic open drive.

Any info appreciated
Thanks
Javier

Did that code come off a plate attached to the transmission?

If it did, what is the color of the plate?

What tonnage/series is the truck.

The color of the ID plate would ID the size (if it is a 1954 H-M transmission):

At this link are GMC tag colors for different sizes of 1954 Hydra-Matic transmission. Chevrolet 1954 H-M tag colors are the same as GMC tag colors on 1/2 (3100 or 100 series), 3/4 (3600 or 150 series), and 1 ton (3800 or 250 series) transmissions.

If it has an open driveshaft, and if it is a 1954 GMC Hydra-Matic transmission, it would have to be from a 3/4 ton or larger truck.

I appreciate all the help, but unfortunately all I have is the rear end from this 54 GMC Hydra-Matic truck.
No trans or color tags to work with just the rear axle.
Ive had it sitting in my back yard for some years. What Im trying to figure out is if this rear end will allow my truck to drive at 60MPH-70MPH?

If GMC rear-end codes are the same as Chevrolet codes:

NK 1224
NK = 1955 1/2 ton rear-end from the Detroit assembly plant
12 = December
24 = 24th

If that is correct, it would be a 3.90:1 rear end (open drive-shaft).