Technical 1957 Olds. Jetaway trans. problems

I have a 57 Olds. with a 4 speed hydro. Problem is no high gear and free wheels on deceleration. I have been told this was common with the early 57 trans. and that the second fluid coupler was not getting oil because they spin and to upgrade to the late 57 coupler. I am considering upgrading to a more modern Chevy trans. I see adaptor kits to do this change over. They are not cheap though. About $1300.00. Has anyone used any of these adaptors in a 57 Olds. and if so what tranny. works out best as far as needing to do modifications to crossmember etc. I already know drive line length.

 

This is a early 57 Olds.

 

The second fluid coupling is full in both 2nd and 4th gears. So if you indeed have an issue with the second coupling second gear would also be affected.

 

Thanks D2_ And in drive it free wheels on deceleration. If you put it in S it will hold back on compression.

 

A friend installed a 200-4R in a 56 Olds. He said he would never go back.

 

Unless you've owned it since new, lord only knows what transmission(s) might have already been swapped into it in the last 64 years.

See if you can find an I.D. tag on the case and someone here can probably decipher exactly what you're dealing with.

 

If your trans has a park detent, then it's probably a Jetaway. W no park I suppose someone could have swapped in an earlier dual range. These are about the only 2 transmission types I can think of that would bolt directly to your 371.

 

It is a 57 Trans. Says O 57 207256 on it.

 

Looking up the actions when in fourth gear is:
2nd coupling fills, rear clutch on. (Both planetary gearsets are in direct drive)
Since 2nd and 3rd gear (in either Dr or Super) are working, it looks like the 3-4 valving is sticking in the 3rd gear position. The 2nd coupling will not fill, therefore free wheeling occurs. A way of testing is to drive the vehicle (in Dr) till it seems to try to shift to 4th (at a slow speed) and make sure it free wheels, then give it more gas and see if it reconnects back to 3rd gear. If it does, then the 3-4 valving is stuck. Shouldn't be a big deal to remove the valve body and try and move the 3-4 valves.

 

You missed the Roto 10 (Slim Jim used on Oldsmobile 394 engines from 1961-64) It should bolt right up. But the Slim Jims were even more finicky than the dual range and Jetaway transmissions. Actually some 1953 Oldsmobiles had Dynaflows bolted up to 303 Olds Rockets due to Hydramatic factory fire. That is a very slim possibility, since most, if not all 1953 Oldsmobiles with Dynaflow are probably non existent.

 

I blew up the transmission in my 56 Olds 989 convertible in 1965 due to a broken left motor mount. Hated that transmission from the day I bought that car. When it blew [foot to the floor -- trans went into reverse due to a broken mount] I dragged the car home and yanked the excellent 324 and put it into a 50 ford. Then I REALLY found out how to trash a transmission!
I'd never own another one of those transmissions.