I decided to drive my truck to work the other day after a 3 year nap in the garage. It's a 57 Chevy one ton panel with a 265 and hydra-matic. Half way to work (5 miles) it upshifted into nothing. I pulled it back into low, it was good. Back in high, nothing. Drove the rest of the way in low. Went out a couple of hours later to try it again. Low ok, no high gears. Stopped to turn around and it was completely gone. Nothing forward or reverse. I've never worked on a hydra-matic before but it looks like I'm gonna. Anybody want to take a guess what happened so I'll know what to look for. Oh, forgot to mention, ex fire department truck, only 18,000 miles. Thanks
what year/brand is truck? factory drivetrain? what is it? mileage does not mean much for vehicles that sit for long periods of time
Pull pan, inspect for shiny stuff, clean screen on pickup. Buy factory shop manual for '57 Chev truck.
You say "low" and "high" gears (???), two gears would be a Powerglide, not a Hydra-Matic, although it could very well be one, and those have 4 forward gears. They also have a Hydra-Matic emblem on the fenders. Toss a can of Trans-Medic, or a similar product in the trans and let it warm up. There are chemicals that "soften" the seals. Then, adjust the bands. A Powerglide would have a single, externally adjustable low band; a Hydra-Matic will have 2 externally adjustable forward bands. If that does't do it, it overhaul time. I am Butch/56sedandelivery.
Had the same thing happen to my '50 Olds back in 1959. Wound it up tight in low gear, shifted to neutral and coasted until it stopped. Repeated procedure 300 times and finally got home. Pulled the trans and threw it in the s**** pile. Good luck.
Guess I could have been clearer on that, Butch. I meant low gear (1st), high gears (plural, as in 2, 3 and 4). It is indeed a hydra-matic. Thanks to everyone for input. I was looking more for information on anything specific I should be looking for on teardown though. I guess (hope) that the problem will be obvious. I will try a band adjustment but I have a su****ion that it's past that due to the sudden failure.
You could try pulling the pressure regulator and let it run for a minute to flush the system.. clean the regulator and put it back on. It's a big plug on the left side of the transmission at the top left corner of the side pan. If that doesn't work and you pull the pan for an inspect.. if you dont see anything broken or metal in the pan you may try cleaning the valve body before you tear into it anymore. I rebuilt a 55 hydramatic a few years ago.. It wasnt that bad of a job. Just pick up a manual on it. If you need any hydramatic parts, I'd highly recommend Dave Edwards - www.autotran.us he has helped me a lot with parts over the years.
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