For the past two days with the help of GREAT friends, we were able to pull the old and tired 4 speed Hydramatic from the GMC 305 V-6.
The Hydramatic Transmission was designed and developed by GM in 1935-36 and was the heaviest transmission GM ever made - how heavy you ask? 465 pounds of Cast Iron and Gears; by comparison my newer 700R4 only weighs 145 pounds. GM used the Hydramatic from 1937-39 in Oldsmobile and Cadillac; and in 1940 to 1967 in other cars, trucks also including tanks. During the war years, the Hydramatic was used in a variety of military vehicles, including the M5 Stuart tank (where two of them were mated to twin Cadillac V8 engines) and the M24 Chaffee light tank. The extensive wartime service greatly improved the postwar engineering of the transmission, later advertised as "battle-tested."
My transmission is the original $300 factory optional transmission and has well over 250,000 miles on it based on paperwork. This transmission is 60 years old and finally broke - the nerve of GM to make such crappy stuff .
I call the last photo "The Quick and the Dead", the hydramatice seems to be looking down on the new 700R.
What failed about the H-M? They're very fixable, usually. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
It would not shift from 1st. gear to 2nd and would barely move in 1st. gear the Hydramatic does not have overdrive and it’s hard for me to cruise at 60-70 without spinning up the RPM's. So I feel it’s an upgrade for cruising. I do hate to change it because I'm a purest, but with that said, the best price I could find to rebuild the 4-speed Hydramatic was from Classic Hydramatic in Livonia, MI. and it came in at $3475, plus $400 round trip shipping and I still would not have overdrive.
The Hydramatic Transmission was designed and developed by GM in 1935-36 and was the heaviest transmission GM ever made - how heavy you ask? 465 pounds of Cast Iron and Gears; by comparison my newer 700R4 only weighs 145 pounds. .
That 100 lbs heavier than the 10L1000 in the latest Duramax.
BC 1960 Chevy C10 driver 261 T5 4.10 dana 44 power loc 1949 GMC 250 project in waiting 1960 C60 pasture art Retired GM dealer tech. 1980 - 2022
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Good luck with getting the TV cable adjusted right. That's one thing it shares with the Hydramatic- - - -it's very sensitive to TV pressure adjustment! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I bought the new TV cable from Bowtie Overdrive and the trans shop will do the adjusting as part of the package. As well as wire in the internal pressure switch.
I can atest to how difficult the 700R4 trans is to get it to shift correctly. i went through two transmissions and a lot of money trying to get the 700R4 behind the 350 Vortec in my '39 Plym to shift correctly. Wm.
Well she's done - took about 12 hours over 3 days but the new 700R is on and bolted up. We still have to set in the 2" x 2" cross brace and do some house keeping, but shes ready for the Trans shop to do the final shift adjustment.... I'll bolt on the dust cover, paint the pan bottom and dry fit the propeller shaft (BTW it looks like I may not have to adjust the length as there is only 1/2-3/4' differance in trans length.
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
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