Technical 1956 Hydramatic "Jetaway"

I wouldn't bet money on it but I'm pretty sure ALL the '56 Olds and Pontiacs came with the infamous Jetaway tran.
I was 16 years old then,. car crazy, read all the car mags and articles, and had a back fence neighbor who had a '56 OLDS, bought new. I can remember the disappointment expressed in every article about the Jetaway's "Slipamatic" lack of get up and go off the line and shift like the old Hydramatic, and later the garage mechanics saying they were almost impossible to repair.
As for the original question, I suspect it would be a job requiring a lot of pre '56 Olds parts espcially if you retained the column shift lever and quadrant.
Hopefully an Olds enthusiast.will see this and help you out if we can keep your post on the first page.

 

Didn't they have oil pressure pipes that cracked causing the servo pressure to drop?

 

Not quite accurate …. early production Deluxe 88 (the cheap 88) and a few Super 88s got the dual range until the Jetaway was in full production, then all 3 lines were Jetaway equipped. The early cars had their own owner's manual ….

 

Shouldn't be that tough to swap in the earlier dual range hydro. Pontiac Chieftans had that trans early in the 56 model year as far as I know. Only difference in the shift quadrant is the park position for the Jetaway. Dont know how the Jetaway could be tagged slow on takeoff w a 3.97 first gear. The Jetaway came into being because of all the compaints about the harsh shifting characteristics of the earlier dual range design. The Jetaway had a pretty long run for being such a supposedly crappy trans...1956 to 1964. Just saying.

 

Been a while since I had the shifting issue. But I had some other priority work in between.

When I opened the pan and found scraps I opted for a complete rebuild and found the issue being caused by the counter weight of the governor chopped off by a defective speedo gear that came loose.

I got me a replacement NOS governor and a rebuild kit and started the task.

 

I completely tore apart the tranny and found a few defects which I rectified as I put together the whole thing again.

 

Latest discovery is a cracked front unit cover...
I did some research but could not find any replacement for my cover #8616404. There is similar ones #8618338 available but I am not sure those will fit...

Anyone of you Techies knowing if I can risk spending money on the part or better save it for some (unknown) other time. Unfortunately it is still impossible finding any parts here in Germany...

Maybe someone of you has a spare I could fall back on?

Thanks!

 

Otherwise it's coming together nicely but slowly.

One outstanding thing is still the speedo drive - someone had replaced the shaft with a later design plastic shaft that he melted into the gear... Didn't hold up well and finally killed my governor.
Meanwhile - as I couldn't get a matching gear shaft I am working on making me one myself... Most interesting task is to fab up the square bore for the speedo cable.

Needs some time but I m getting there.

 

Also... This is how the right hand side engine/transmission mount looked when I removed the transmission... Glad I noticed before it went completely mid driving...

 

I don't know anything about these trannies. Is there much pressure behind the cover? If not you can probably fix the crack with JB weld or a similar metal impregnated epoxy. I had good luck fixing an actual hole in an atv trans.

 

Have you called Fatsco? They are THE authority on obsolete transmission including the Jetaway. I'm spoiled with them being right here in my backyard in NJ, and I know they stock a ton of obsolete parts and random stuff. It's worth a call to them to see if they have a replacement cover. And they ship internationally.

 

When these transmissions came out there were lots of problems with them. I never liked them. Once, I had a '56 totally quit while trying to get it into the garage for another problem. If you could find a '55 Hydromatic and an adapter that's what I'd do. Those were one tough transmission.

 

Yeah, found a cover at Fatsco that I ordered. Got shipping confirmation and should be here early January.
Fingers crossed not many more issues surfacing on the rebuild... Costs for part, international shipping, customs dues and fees plus waiting time just killing me...

 

Since the frunt coupling is a flzid coupling witch driving/driven torusses there is quite some fluid motions in there and I once at it I really would not go down the route of gambling... On top the entire unit is supposed to be balanced so it doesnt wear the bushings messing up more of the components - so sticking jb weld on it won't do an acceptable job fixing the issue...

 

That's plan C if not being successful at all with the rebuild...or for one day when I have too much time at hands and won the lottery...

 

Stick with it. My 56 98 was a pleasure to drive after the Jetaway was rebuilt.

 

Johnny-- My first car at 15yo was a 1957 Pontiac with a Jetaway. First upgrade was dual exhaust and I loved to hear those mufflers on decell. A mechanic told me not to downshift that transmission if I expected it to last. What could he know? A few months later the neighborhood trans shop extended me my first line of credit in 1963 to overhaul and replace the "salad bowl" along with the other worn parts. It took me almost a year to pay them off at 10-15$ each payday. First thing he told me when I picked it up a month later was (DO NOT DOWNSHIFT!!) One of many life lessons learned along the way. DC

 

Lol... Will surely remember your advise.

 

Got a nice present from Fatsco in time for Christmas...
Had some time to remove the old front unit cover and found it was about time that thing will be replaced. Barely holding together...completely cracked.

'Don't downshift!'

 

Next task is to remove the old shaft bushing ring from the old part without damage so I can re-install it on the new cover.
Unfortunately not been able to locate a new replacement yet.

Maybe heating up the old cover in the oven...?
Would not like to start using force e.g. pullers or driving it out from the back as I fear damaging it.

 

Not going to be much help but I remember the guy that rebuilt mine years ago telling me he had put parts into the freezer overnight to get them apart or reassembled.

 

Hmmm.
Why not. Freezing makes metals contract. Worth a try

 

Putting a 55 hydramatic in your 56 Olds is pretty easy. The transmission doesn't need an adapter to mate up to the engine. But you will need to have the crankshaft drilled for a pilot bushing. You will need the 55 (or 56) hydramatic flywheel, and perhaps the crossmember with mounts from a 55 or 56 hydramatic Olds may be needed. Driveshaft and yoke may need updating. You can get by with the quadrant indicator, just don't have Park. As you can see, it isn't too hard to do.

 

Another great source for parts for these old transmissions is Dave Edwards ( AutoTran).

 

Didn't work out.
According to Fatsco I should not worry. Will work without this. It's just a different design.

 

Cut the old part apart, just don't nick the outside of what your after.
Does this piece fit the replacement part you have?