What tranny do we have?
- Thread starter BigAl...
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Blake
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This comes up a lot for some reason. Just like the other guys said, we have a 700r4. The 700r4 is exactly the same thing as the H4L60(Hydramatic 4L60). GM just changed the name to match the rest of the lineup of Hydramatic trannies.
In late 1987 GM changed the 700r4(4L60) a great deal. Input drum improved, pump improved, sprag improved, parts inside were hardened, etc.
In 1993, GM made some more improvements to the innerds of the input drum, the pressure regulator valve had a slight mod, the case was changed slightly(required a different separator plate)and an additional checkball in the valvebody as well as an improved reverse input drum.
Recently GM went to 5 pinion planetaries in their 4L60E's. These 5 pinion planetaries fit right into our trannies with no modification if you want to spend the money for them. Another nice thing GM did was went to a beefier sun gear shell(these fail often in 700s). Some places sell them as the "Beast" sun gear shell.
The difference in the SyTy tranny over regular 700s is the accumulator valve in the valvebody is the largest available(firmer shift),throttle valve has ability to allow 3rd gear to 4th gear upshift at WOT, it has the "093" 1-2 servo out of the corvette(this is the largest GM makes), it also has a .471" TV boost valve in the pump itself and a green spring in the pressure regulator lineup.
The Syclone has a different governor than other "S-10" style trucks. It is NOT a corvette governor. Recently someone said that the Ty governor is different than the Sy governor to accomidate the different weight of the vehicle. I haven't really paid that close of attention to know for sure but it came from a person who knows what they are talking about.
Syclones and Typhoons did not have a Kevlar 2-4 band in them from the factory. I hear that all the time. Not true.
Syclones had an output shaft that had two additional lube grooves in the end that rode on the bushing the farthest back. When I did my Ty's tranny, it didn't have the two extra grooves.
Don't get a 4L60E filter. It won't fit our trucks no matter what the guy behind the counter tells you. Transtar had a reference in their catalog that the Ty had a 4L80E and that the Sy had a 4L60E. These are both WRONG. Talk to the shop a long time before you turn them loose on your trans.
Torque converter is a problem also. The SyTy torque converter stock is 2075 rpm. It will have "7"s stamped around the circumference. I've heard a few people ended up with 1600 rpm stall converters after rebuilds because that is what is behind the normally aspirated 4.3L engines.
And so ends another Blake novel.
Sorry this was so long guys.
In late 1987 GM changed the 700r4(4L60) a great deal. Input drum improved, pump improved, sprag improved, parts inside were hardened, etc.
In 1993, GM made some more improvements to the innerds of the input drum, the pressure regulator valve had a slight mod, the case was changed slightly(required a different separator plate)and an additional checkball in the valvebody as well as an improved reverse input drum.
Recently GM went to 5 pinion planetaries in their 4L60E's. These 5 pinion planetaries fit right into our trannies with no modification if you want to spend the money for them. Another nice thing GM did was went to a beefier sun gear shell(these fail often in 700s). Some places sell them as the "Beast" sun gear shell.
The difference in the SyTy tranny over regular 700s is the accumulator valve in the valvebody is the largest available(firmer shift),throttle valve has ability to allow 3rd gear to 4th gear upshift at WOT, it has the "093" 1-2 servo out of the corvette(this is the largest GM makes), it also has a .471" TV boost valve in the pump itself and a green spring in the pressure regulator lineup.
The Syclone has a different governor than other "S-10" style trucks. It is NOT a corvette governor. Recently someone said that the Ty governor is different than the Sy governor to accomidate the different weight of the vehicle. I haven't really paid that close of attention to know for sure but it came from a person who knows what they are talking about.
Syclones and Typhoons did not have a Kevlar 2-4 band in them from the factory. I hear that all the time. Not true.
Syclones had an output shaft that had two additional lube grooves in the end that rode on the bushing the farthest back. When I did my Ty's tranny, it didn't have the two extra grooves.
Don't get a 4L60E filter. It won't fit our trucks no matter what the guy behind the counter tells you. Transtar had a reference in their catalog that the Ty had a 4L80E and that the Sy had a 4L60E. These are both WRONG. Talk to the shop a long time before you turn them loose on your trans.
Torque converter is a problem also. The SyTy torque converter stock is 2075 rpm. It will have "7"s stamped around the circumference. I've heard a few people ended up with 1600 rpm stall converters after rebuilds because that is what is behind the normally aspirated 4.3L engines.
And so ends another Blake novel.
Sorry this was so long guys.