The Stovebolt Site Forums The Shop Area Driveline Visit with Hydramatics By Gene

Hey Folks, I recently visited my family in Salinas, California, and while there I called Gene of Transmissions by Gene. If you own a Hydramatic transmission, you need to know this man. I left a message, and within a few minutes he returned my call. He invited me to his shop. Wow, what a great guy. He spent 3.5 hours of his prescious time explaining to me the various details of Hydramatics and stories of his life involved with cars. I am amazed at the wealth of information this man is able to pull out of his computer like brain. I will forever be thankful that he took the time to meet with me.

Since I grew up around a shop owned by my father who was the first man in Nashville to work on automatic transmissions in the late 1940's, I know exactly what you mean. The HydraMatic was one of the best-engineered automatic transmissions ever, and most of the so-called "improvements" in later designs were for driver comfort, not actual better operation. People didn't like the positive shifts the early ones had, which led to changes that allowed for soft, mushy shifting.

Dual-range transmissions even had a feature that allowed the rear pump (driven by the driveshaft) to take over the hydraulic demand, and take the load off the engine-driven hydraulic pump. This reduces the power consumed by the transmission pretty dramatically. That's only one of many details about this transmission that puts it way above a lot of others, quality-wise.
Jerry

Ted,

Gene is an interesting and knowledgeable fellow. I hope to meet him some day. I also hope to save up the $$$ to have one of my Hydra-Matics rebuilt by him.

Restoration Hydra-Matics, Salinas, CA

Thanks Ted for posting the information about Transmissions by Gene. Do you have a vintage automatic transmission or just having fun with GM history while on vacation in Salinas? I went on Gene's website and found he has many photos of old transmissions in the "Examples" section. I was impressed that all rebuilt transmissions have a five year warranty. The next time I drive up north, I am going to visit Gene's shop. I have a 1954 five window 3100 with the original hydramatic trans and Patrick's ring and pinion gears. The hydramatic is really a fun transmission to drive. The trans has the old 1-2, 1-3 and 1-4 gear selector so you can control how many times it shifts. The trans shifts up quickly through the gears. The Chevy truck manual says to use the 1-3 range when driving in town to prevent shifting into 4th gear at lower speeds. The gear selector shifts without the detents or clicks felt when shifting later automatic transmissions. I don't have any problem keeping up with the California freeway traffic with the hydramatic and Patrick's gears. I like having old timers with experience work on vintage transmissions. Just had the two speed aluminum powerglide in my 1963 Impala project wagon rebuilt at Ohta-Matic Transmissions in Anaheim. They don't rebuild hydramatics anymore. The son runs the shop now but when an old powerglide trans needs a rebuild, the original owner, Grandpa Ohta, comes in to inspect and assemble the trans, when everything is ready. The son says his dad did several powerglides a day when the powerglides were plentiful. Cost me $600 plus hard parts = total $680. Drove it on a 3700 mile trip in September, pulling a 14' 1950 travel trailer, and it worked perfectly.

It's about $3,000 for Gene's rebuild (plus shipping both ways).
I think it would be the same price for Rolls-Royce, Cadillac, or Chevrolet.

Most likely the 21-speed GMC Hydra-Matic would be a higher price?

Thanks for sharing the costs at Gene's. I have never heard of a 21 speed. Sounds like it is a truck or military trans?

There is such a thing as the 21 speed. Gene showed me a diagram of one. He said he was going to email me the design, but I haven't seen it yet.

I sent the original 17.5"x38" exploded-parts diagram of the 21-speed Twin Hydra-Matic to Gene (with a GMC 1955 Operation and maintenance manual). He kindly sent me one of the copies he had made.

Simply described (as if I know anything about Hydra-Matics), the Twin Hydra-Matic is two 4-speed hydra-matic transmissions mounted above/below each other. They each have a front and a rear input and output shaft. Together, they have 7 forward speeds and one reverse speed.

"The rear transfer gears/case connect power through a common output shaft to a two or three-speed reduction unit."(14 forward speeds or 21 forward speeds) A two-speed reduction unit was standard, and the three-speed reduction unit was optional equipment. The transmissions were available on 600-900 series GMC trucks.

Gene had told me that someone had called and spoke with him about the 21 speed. He also mentioned that he had received the manual from that same person. Now I know who actually sent it! Man, the web is something else.

Thanks for the education. I sure would like to drive a 21 speed for the fun of it.