Technical Hydramatic locked up

The strato flight in my 57 pontiac has been super reliable and consistent performing..other day I pulled out driveway and it harsh shifted the 1-2 shift then immediately shut off..attempted to restart and now motor is stuck in place and won't spin over..removed inspection cover and trying to pry motor over by hand it's stuck one way and will barely budge other direction...can this style torus and coupler style trans cause the engine to seize when the trans does? Really feel as if it's a trans issue and not an engine related failure

 

You can always unbolt the flex plate and see if the engine frees up right?

 

As I remember the transmission fluid from the torque converter cover will need to be drained and the 30 or so bolts be removed to separate the engine from the transmission. PITA.

 

The dual range hydros have the 30 bolt issue, but your 57 hydro is a dual coupling unit and does not have that issue. The dual coupling units have park position on the shift indicator.

 

The '57 will still need the torus to be split. The hard part will be finding someone familiar with those Strato Flights

 

True mine does have park posistion and I don't believe it to have the 30 or 32 bolts however when I was at the car I remember seeing multiple fasteners in the lower section I could see with cover off..i remember seeing studs with nuts on em...on this unit is the torus or converter still held in with snap ring? Can't really wrap my head around how I'm going to remove trans if I can't rotate it and if the torus or converter doesn't slide out..dual range trans have torus or torque converter? Dual coupler trans have torus or converter? Thanks in advance

 

We just did a 56 Pontiac with the Park, the torus stayed bolted together and there were 3 or 4 bolts that unbolt the torus from the flywheel.

 

Yes, you have a major problem in that you can't turn the engine to get at all the bolts. I'd be working to see if I could get it to turn. Plan 2 would be to unbolt the transmission and pull the engine and torus.

I also think that your engine should have enough power to destroy most things that would cause a transmission to try and lock up. It may be your engine that is the problem.

 

Could your engine be hydro locked? Pull all the spark plugs and see if the starter will turn it over.

 

Thanks all for the input I will definitely pull plugs to verify its not hydrolocked before pulling engine and trans together.. Engine really ran excellent but anythings possible..i will post back progress

 

There are few things in life worse than trying to get a hydramatic off when it can't spin.

I don't understand what would cause a trans to lock up like that, especially an automatic that has a fluid coupling. My guess would be engine between the two. My Y block ran the best it ever had right up until the moment the cam was torn in 4 pieces and it had a tire-locking seize at 70 mph.

 

Finally got back around to working on car this weekend and since I posted last I acquired another complete 347 4 barrell pontiac motor and 4 speed hydramatic for spares or cores to build..Once I removed exhaust fully from car I had a better pry spot with good leverage on flywheel and was able to rotate engine enough to unbolt it from flywheel. Really took some serious force to rotate motor and had a spring back effect when releasing pressure off it.
I had planned to pull motor and Trans together then cut thru my lower bell housing to seperate trans off motor since it's aluminum and I had a spare. But i brute forced the motor to rotate and unbolted and all is well..I will update on what component failed in the unit to cause such a siezure..I imagine there's been many gm products that use this Trans type that have been misdiagnosed as a seized engine. Sure had me puzzled and second guessing things I thought to be true.

 

Wasn't hydro locked I guess ?

 

No it wasn't motor is good to ! I've ran it with no trans

 

I have a spare 1957 trans I bought two years ago. Said to be good, leaked a little. I don't need it. But I'm way out here in California.

 

If the Stratoflight dual coupling hydramatic is setup like the older dual range hydramatic, then the front planetary is locked up. The torus sends engine power through the front planetary and out to the "drive " coupling half to slow down the coupling speed to reduce creep at idle.

 

Couldn't find a trans builder in my area that would attempt the rebuild for me so I tore into it myself and wanted to share what I found to be the culprit of the locked up dual coupler hydramatic..torus outer shell was removed first and upon inspection the torus internals spun freely and were easily removed with some snap ring pliers and all pieces including planetary inside all in good shape..rear torus half pulled out and showed no damage..so basically torus assy is one coupler that splines into the second coupler hence dual coupler trans..anyhow the second coupler would not spin..pulled filter then valve body then servo all easily removed as well. The servo cup that holds spring was FULL of metal..uh oh..it was then I seen an access hole behind the second coupler..thru that hole you could see the snap ring that holds the second coupler together out of place loose and bound up in between the trans case and the second coupler.

 

It was thru this hole that I got on back side of the second coupler and was able to finally knock it forward out of trans..I haven't yet disassembled this second coupler to inspect inside but probably gonna replace this assembly.. one of the four drive tabs are broke off also..

 

I've recently found a great teardown video on these style units on you tube..automatic transmission is channel name and hes disassembling a jetaway 315 out of a 57 cadillac and he finds it to have the same snap ring off of it as well on the second coupler

 

Good for you diving into like that. I’ll be pulling the ‘59 Pontiac Jetaway out of mine very soon to reseal it. Mine seems to work but it’s pouring fluid out of the bellhousing dust cover. Post lots of pictures, I’m sure that I’m not the only one who is curious.

 

That was a common problem in those Transmissons. My first car at 16yo was a 57 347. About 6 months after I got it the trans quit. The mechanic that fixed it told me not to downshift any more. The "salad bowl" was the weak point of those units.

 

Wow, great detective work. It may be a common problem... is there a root cause to let the snap ring get into that position? My '64 Olds with the slim-jim leaked like a sieve. At the time it was $45 to reseal them. Who had that sort of change in 1973?

Me and my brother pulled it, we took it to a transmission shop to see if it was a simple seal or something deeper. The guy looked it over, all said and done the new front and rear tailshaft seals were in for $6.