TH350 non-lockup to lockup?

[drman929]

Is there any way to make this happen without getting a new tranny? With a lockup 350, does the converter lock in any gear or just 3rd? Are there performance benefits to the lockup? TIA

[piecesparts]

The lock-up actually gives a small amount of mileage increase, due to dropping the RPMS slightly. My son's lock-up started messing up in his 86 and the tranny shop unplugged it, until we could get time to do the replacement with a 700R4. The change in RPMs dropped his gas mileage by about 2 MPG.

[GREASEMONKEY72]

im kinda curious about the whole lock-up deal to so heres a bump for you

[GREASEMONKEY72]

Originally Posted by piecesparts

The lock-up actually gives a small amount of mileage increase, due to dropping the RPMS slightly. My son's lock-up started messing up in his 86 and the tranny shop unplugged it, until we could get time to do the replacement with a 700R4. The change in RPMs dropped his gas mileage by about 2 MPG.

what exactly is a "lock-up"?

[BarryB]

the lock up part is in the converter.
A clutch has been added to the torque converter to mechanically "lock" the engine to the transmission input shaft, eliminating the "slippage" and gaining the fuel mileage that normally lost in an automatic transmission.

[GREASEMONKEY72]

Originally Posted by BarryB

the lock up part is in the converter.
A clutch has been added to the torque converter to mechanically "lock" the engine to the transmission input shaft, eliminating the "slippage" and gaining the fuel mileage that normally lost in an automatic transmission.

ah ok, i get it now, how much is a lock-up kit for a th350?

[GREASEMONKEY72]

Originally Posted by drman929

Is there any way to make this happen without getting a new tranny? With a lockup 350, does the converter lock in any gear or just 3rd? Are there performance benefits to the lockup? TIA

sorry for stealin your thread dude but maybe im asking the right stuff???

[Evans]

They don't make a lock-up torque converter for a TH 350 .... 700r4 and 200r4 are Chevys trannies that have lock-up functions

[GREASEMONKEY72]

Originally Posted by Evans

They don't make a lock-up torque converter for a TH 350 .... 700r4 and 200r4 are Chevys trannies that have lock-up functions

dagnabit, ohwell

[GMC Jim]

They do make a 350 with a lockup torque converter. Don't recall the correct numbers for it but I had one installed in a '79 Cad Seville I owned a few years ago.

[Palf70Step]

The T350C are the ones with lockup converters. I believes they ran from 80 to around 86. The converters do NOT interchange. I know I tried to go the other way, making my T350C a normal T350.

The T350Cs are not real strong, so I am told, so if you want to run an engine with any guts, (modified small block) I would look at something else.

[Evans]

My bad then , never heard of a lock up 350

[cooters]

all t350 trannys in the 80s were lockup including 4x4, the converters are weaker but they do make good ones if you want to pay the buck.

[piecesparts]

The 350C trannys (lock-up type) were basically TH350 trannies, however the lockup converter was different as well as the input shaft (which was smaller and lighterweight) This was the downfall of that tranny design. I got over a 100,000 miles out of mine before I got the desire to go OD and real horsepower. The lockup feature is a solenoid that feeds more pressure to the converter to get rid of some of the fluid slippage in the vanes inside. This pressure ensured that the vanes aligned and the converter provided a more positive output.

A standard 350 cannot be modified for this design. You should look at an overdrive tranny and get the best of both worlds. Right now I have a 700R4 in my truck to get the OD, but I eliminated the lockup converter and installed a 2400 stall converter to make ofr the cam that I am running in my 383 motor. I get the stall feature and lower RPMs on the highway. I have over 400 horses and get 15 mpg on 3.73 gears. I realize that is not outstanding in thsi day and age, but there are cheesy Toyotas getting the same in their little trash bins and they can't kick a Mustang's butt for nothing.

[drman929]

Thanks guys. Well I guess I'll stick with my non lock-up then.

Grease--do whatever you want to man, your questions will probably help me too!