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As a kid, I thought the Hydramatic transmission in our '60 Olds was really cool--quite different from the powerglide in the old Chev we previously owned.
When I heard the newer '61-'64 GM Buick Olds and Pontiacs accellerate, I wondered why they had a big rpm drop off in the 1-2 shift. I later found that they used the Roto Hydramatic which were quite inferior. It was a great day when GM introduced the TH-400.
http://ateupwithmotor.com/technology...2.html?start=2
Slim Jim?
http://en.wikipedia.org/wiki/GM_Roto...c_transmission
http://en.wikipedia.org/wiki/Hydramatic
http://ateupwithmotor.com/technology...1.html?start=2
When I heard the newer '61-'64 GM Buick Olds and Pontiacs accellerate, I wondered why they had a big rpm drop off in the 1-2 shift. I later found that they used the Roto Hydramatic which were quite inferior. It was a great day when GM introduced the TH-400.
Roto-Hydramatic 375
Also known as Model 10 or Slim Jim.
Used 1961-64 in some Buick, Olds and Pontiac models.
There is some disagreement as to this being a 3 or 4 speed transmission. It only shifted twice, so many people consider it a 3 speed, but it had an internal torus torque multiplier (similar in principle AND operation to today's torque converters) that did give it an initial additional "ratio".
Do not confuse with 375 THM used later that was an adaptation of the 400 THM, but with a 350 THM size output shaft spline or the version of the 350 THM that GM called a 375 THM.
This was an hydraulically controlled transmission.
Gear Ratios:
starts out at 3.50:1 and becomes 2.93:1 when "torus becomes hydraulically coupled" 1st gear
1.56:1 2nd gear
1.00:1 3rd gear
2.42:1 reverse
Also known as Model 10 or Slim Jim.
Used 1961-64 in some Buick, Olds and Pontiac models.
There is some disagreement as to this being a 3 or 4 speed transmission. It only shifted twice, so many people consider it a 3 speed, but it had an internal torus torque multiplier (similar in principle AND operation to today's torque converters) that did give it an initial additional "ratio".
Do not confuse with 375 THM used later that was an adaptation of the 400 THM, but with a 350 THM size output shaft spline or the version of the 350 THM that GM called a 375 THM.
This was an hydraulically controlled transmission.
Gear Ratios:
starts out at 3.50:1 and becomes 2.93:1 when "torus becomes hydraulically coupled" 1st gear
1.56:1 2nd gear
1.00:1 3rd gear
2.42:1 reverse
http://ateupwithmotor.com/technology...2.html?start=2
Slim Jim?
http://en.wikipedia.org/wiki/GM_Roto...c_transmission
http://en.wikipedia.org/wiki/Hydramatic
http://ateupwithmotor.com/technology...1.html?start=2