[joshp83]

got a 57 pontiac at my shop with the dual range hydro cant talk the owner in to a 700r4 looking up info on line to improve performance my dad is real familer with theses units but in stock form im building up the 347 v8 want the trans to have a firmer shifts no one ive found offers any shift kits for this unit

[junior stocker]

I "think" you've got your early transmissions mixed up some. The 57 would have had a "dual coupling" style trans, not a "dual range". The dual range is ALL cast iron, with a driver side and bottom cover/pan; it is what the B & M Hydro Sticks were built from, along with other companies racing trans. The dual coupling never was a performance trans; you may be able to increase it's line pressure some by stretching or shimming the right spring/springs, to make it shift harder/faster, but that's probably about it. Maybe after your customer realizes he has the "wrong" trans to modify, he'll change his mind about the 700R4 trans. Even at that, I'd opt for a TH400 trans. Butch/junior stocker.

[John long]

The factory that built the Hydromatics burned during the 1956 model year and GM went to the "Jetaway" hydromatic. The reason it shifts so smoothly is because the shift from 1st to 2nd is done by a spraque unit instead of bands. The shift from 2nd to 3rd is a mechanical shift with bands and the final shift from 3rd to 4th is another hydraulic shift. I don't think there is much that can be done with them for performance but I am no Transmission man. Just owned 57 Olds until a few years ago and had studied the trans some.

John L.

[Crosley]

I think the GM Hydramatic Plant fire was in 1952 or 53.

[John long]

Originally Posted by Crosley

I think the GM Hydramatic Plant fire was in 1952 or 53.

You are right Crosly. Aug 12, 1953. I am not sure why the Olds line was able to continue to install the early Hydros until 1956. Here is a link to the fire.

The Great Hydra-Matic Fire

John L

[joshp83]

it is a jetaway unit i found info about the old hydro sticks from b &m but none on this unit i know this unit is durable just not sure about the performance potential

[anglia427]

its a dual coupling for first and second shift if its still good go with it