Projects 54 hydramatic in a 55.1

Hi, everyone. Hoping someone could tell me how hard it would be to swap a 54 hydramatic pickup transmission(torque tube) into a 55 first series Suburban (open driveline). Thanks in advance!

 

I didn't realize the "hydramatics" had a torque tube, I've never seen one. Is this a GMC?

Pat

 

^^^same here^^^

 

the 1954 pickup still used a torque tube in the driveline.

the 55 first series was an open driveline.

it’s a Chevrolet Carryall Suburban

 

That would be a bolt-in IF you had the rear axle/torque tube from the '54. The torque tube is '54 hydro only - it's a few inches shorter ...

 

Pictures? I put a '55 Pontiac hydramatic in my "first '49 Ford Coupe with a '58 Pontiac engine, and it was open shaft. Probably going to be tough to find an open shaft tailpiece...the transmission is pretty easy to rebuild....it must be, because I did it when I was 17..even did the B&M drum machining and added clutches as outlined in Hot Rod magazine......60 years ago...

Wish I could actually help.

And the first time I "stood on it" I broke the motor mounts...

 

So swap the whole driveline too?

There isnt a way to stay open driveline on my 55?

 

@1955firstSuburban. It shouldnt be to difficult to find an open drive tailhousing and shaft for a hydramatic.

 

Know of a place?

I have the shaft since it’s a 55 or are you not referring to the open driveline?

Thank you

 

I was referring to the output shaft and matching tailhousing for the hydramatic. When I was looking for a dual range hydramatic about a year ago I checked on facebook marketplace and I was able to find 5 for sale nearby within about a week.

 

Curious, was the Hydramatic offered in those years of PUs? I’ve only seen a few in 55-9 GMCs.

 

'54 - '59 Chev, '53 - '59 GMC
GMC first offered hydro in '52 for stepvan chassis ...

 

Ok, copy that. So id need to find a drive shaft and tail housing to fit?

I was told id need a new flywheel too?..

So look for one specific to a 1955? Or what years would work? Thank you

 

I dont know if you'll be needing a new driveshaft or not but there are different length output shafts with their corresponding tailhousings. Some of those tailhousings will have mounting holes while others do not.

 

A guy sells these in Northern California. Wonder if it’s GM.

 

You just need to find an open driveline tail shaft and housing. Will bolt right up. In fact I have a parts tranny in my shop will look at it and take pictures tomorrow for you, If you can use it I'll send it.

 

Any hydramatic open driveshaft housing should fit ok? As long as from truck to suburban?

 

I took a picture this evening. This is the tail shaft/output shaft I have.

 

'54 & '55 Chev 1st series 6v are same, '55 2nd - '59 Chev 6 12v same.
GMC flywheels won't fit Chev - crank flange pattern different.

 

Ill snap a photo tomorrow and upload it. Thanks, Willie!

 

Ok, I was told the 54 and 55.1 flywheel were different.
Worth looking into. Thank you.

 

You can have mine if it will fit.

 

What city are you in, Willy?

you really think that open drive shaft and housing will fit my 1954 hydramatic? Is it from a hydramatic?? Thanks, Willy!!

 

Van Alstyne Texas (20 mi north of Dallas). Absolutely will fit. Both of the trannys are Dual Range Hydros so everything interchanges.

 

awesome!! Thanks, Willie. That’s awful kind of you.
Will I need to change any parts? Suppose ill need some new seals?


could I have someone pick it up for shipment in that case?

 

You are taxing my way-back brain cells!! I think you will just need the round paper gasket, worst case you could make your own. Don't recall if there is an O-ring seal back there. Regardless, it is an easy swap. Of course you will need to find a yoke too.

That would be great if you have someone who could pick it up in person.

 

I reviewed the assembly of the tranny and it is a bit more involved taking out the shaft/housing but not too bad. Need to drop the bottom pan. take off the rear band solenoid and governor and unbolt a ring of bolts attaching it to the power train.

There is a great series of tech videos on the net. showing step by step assembly and everything else about the theory of this great machine. Here is the first video of the 5 he produced. I downloaded them all. Just follow the series and you will be an expert!

 

You will need to open up the transmission to get to the rear shaft. This is retained by 6 small bolts. With the extension housing and oil pan removed, all remaining is the rear shaft and reverse planetary assembly. Note: The inner input shaft will need to be removed in order to get rear shaft/reverse planetary out.

 

the existing yoke wont hook up?

found this pic on ebay

 

Don't know. Never worked with closed drive lines but that yoke looks like it might work. All depends on the splines matching up.