hydramatic 4speed auto

[tommyduncan]

I just bought a 62 GMC with a 305 V6 and a Hydramatic 4 speed auto.

How common is this combo? Will it be impossible to find trans mount or a starter in the future? Should I keep it? I like unique drivetrains...
Can anyone break down the VIN on these years?
Thanks for any help. I will need engine parts eventually. A barrel nut passed through the engine and it was parked afterwards.

[Funky61]

Welcome TD! have you checked out Jolly's Site located here. Lots of Info.

http://www.6066gmcguy.org/SM420.htm

[jbgroby]

Tommy,

I too have a 305 mated to a hydramatic. They are so rare they're almost a rumor as one trucker told me

The combo was very popular in the day for folks who wanted to "hold" their gal at the lights, the other men drove a stick.

It is not a bad combo I love people who scratch their heads when they take a look.

[tommyduncan]

Originally Posted by Funky61

Welcome TD! have you checked out Jolly's Site located here. Lots of Info.

http://www.6066gmcguy.org/SM420.htm

Thanks! I was on there before I knew this truck was an auto and I missed the info on the autos. I will be spending more time on there for sure(when I have some time).

Originally Posted by jbgroby

Tommy,

I too have a 305 mated to a hydramatic. They are so rare they're almost a rumor as one trucker told me

The combo was very popular in the day for folks who wanted to "hold" their gal at the lights, the other men drove a stick.

It is not a bad combo I love people who scratch their heads when they take a look.

Nice! Since yours was out at one time what would you estimate the weight of it?

From what I read the odd gear pattern using reverse as park with the engine off hasn't been used since the early 50's. Is yours the same way?

[jbgroby]

On the weight I estimate about 125ish I used an engine hoist to move it into position. The reverse serves as park when the engine is turned off (I believe a can drops in place and keeps the gears from turning - not sure though).

Putting the 32-35 bolts in the fly wheel was a blast I have large hands and fitting them through the maintenance access hatch was a bit rough, but once I got 3 or 4 in it was just a matter of time.

[David R Leifheit]

Originally Posted by tommyduncan

I just bought a 62 GMC with a 305 V6 and a Hydramatic 4 speed auto.

Can anyone break down the VIN on these years?

1502 CJ 3272B

15 - 1500 series
02 - 127" wheelbase
C - built in Oakland California
J - 1962
3272 - 2272nd truck built (truck #1 was 1001)
B - 6001-10,000 GVW class

In short, you have a 1962 GMC "3/4 ton" pickup.

[tommyduncan]

Originally Posted by jbgroby

The combo was very popular in the day for folks who wanted to "hold" their gal at the lights, the other men drove a stick.

"Stickshifts and safetybelts
Bucket seats have all got to go
When we’re driving in the car
It makes my baby seem so far

I need you here with me
Not way over in a bucket seat
I need you to be here with me
Not way over in a bucket seat"

Cake-Stickshifts and Safety Belts

This will be the first vehicle I have owned in a very long time with a bench seat
...other than painting it red(which isn't my first choice) maybe this will get my old lady to like it. If that fails I will just talk about buying a new one and she will be ok with this one

[GMCDAC]

Originally Posted by tommyduncan

I just bought a 62 GMC with a 305 V6 and a Hydramatic 4 speed auto.

How common is this combo? Will it be impossible to find trans mount or a starter in the future? Should I keep it? I like unique drivetrains...
Can anyone break down the VIN on these years?
Thanks for any help. I will need engine parts eventually. A barrel nut passed through the engine and it was parked afterwards.

Hey Tommy and everyone, I'm bringing this back up as I have a question about the hydramatic differences. This is a 60 or 61 GMC but the indicator looks much different overall. Is there a top piece that is broken off or removed? Every truck I have ever owned older than 1970 was a 4 speed clutch type so I have no knowledge of them besides what I read here.

When I took that pic a while back i didn't think to take a better pic of the indicator so I had to crop it out of a larger one.

Thanks---DAC

[1969_CM2590D]

Originally Posted by GMCDAC

Hey Tommy and everyone, I'm bringing this back up as I have a question about the hydramatic differences. This is a 60 or 61 GMC but the indicator looks much different overall. Is there a top piece that is broken off or removed? Every truck I have ever owned older than 1970 was a 4 speed clutch type so I have no knowledge of them besides what I read here.

When I took that pic a while back i didn't think to take a better pic of the indicator so I had to crop it out of a larger one.

Thanks---DAC

Doug I can remember in many of the "cheaper applications" if you will, the shift indicator was almost entirely plexiglass with metal side supports, as in the truck you found. Very much of an add on appearance. Lots of Powerglides (or Pow-r-Flows?) on Chevys had this type of shift indicator. It was plexiglas with side metal on my folks' '60 Bel Air, '64 Impala, and '66 Chevelle 300 Deluxe (all Powerglide of course).

Here is a shot of a '60 Bel Air for example... however the B-O-P's and Cadillacs had their indicators in the dash. I suppose when the interiors were styled, those GM vehicles that would have a huge chunk of manuals produced got the add-on shift indicators (?)

[1969_CM2590D]

Ok you guys got me all motorhead geeky here. I may be repeating stuff that a lot of you know, but for those that don't...

These GMC"S have the ORIGINAL Hydra-matic! No Park, no Drive (on the truck application- "D" on the cars, though), no torque converter. I've enclose a photo here of Hydra-Matic 1.0 in a 1949 Pontiac. Not to be confused with Dual-Range or Jetaway Hydra-Matic.The pawl that immobilizes the drivetrain is engaged with the engine off, then put in reverse. Full "Drive" is that "1-4" on the shift indicator. This last iteration of Hydra-matic 1.0 finally ended in the 1962 GM trucks.

This thing was stout. This is from Wikipedia:

The all cast-iron Hydramatic was the heaviest automatic transmission ever produced for automobiles. The heaviest of them all was the Truck Hydra-Matic version offered by GM Truck and Coach Division in its line of light- and medium-duty trucks and conventional buses, as well as with its transverse mounted gas L6 engined transit buses produced until 1963. That particular version weighed in at an incredible 655 pounds, when equipped with the angle drive for the transit bus application, while the ¾ ton and up pickup truck model (HM270) still tipped the scale at a solid 435 pounds. When coupled to GMC's heavy V6 powerplant of 1960-1962, the powertrain weight was not too much lighter than the weight of the entire body of a ¾ ton P-2500 model pickup truck. Even its successor, the Controlled Coupling Hydramatic was reviled by shop mechanics having to remove or reinstall such a unit, as they, too, were quite heavy when compared to other contemporary units. In the end, the true Hydramatic was rendered obsolete because of its cost, both in raw materials used as well as the machining needed. The successor, Turbo Hydramatic, was a much simpler, lighter and cheaper, if less efficient, transmission.

Anyone have the Owner's Manual section on this to post? I'd like to see it.

Obviously the transmission (and drivetrain) of choice for heavy duty, long life applications. An HD Powerglide pales..