J-(Chicago)

Jim on this board scored me a free 350 trans for the new delta 88 project I was going to pick up a nice torque converter for it, but happened to notice that there is what looks to be an oil pressure sending unit next to the dipstick tube.
I do not know what this is and my Other 350 transmission does not have it. I fear that it may be a 350c lockup. Hopefully, there are obvious differences between the 2. Could someone here point them out for me?

occupant

That would be my guess, and I love my 350C. I love going 50-55mph and hearing the engine drop to a low groan as my speedometer effortlessly rises to 65-70mph.

shaks 442 clone

whats a 350c?

occupant

turbo 350 with a lockup torque converter...the wiring plug he speaks of is connected to the lockup solenoid in the transmission which allows the converter to go into a lockup mode, reducing converter slippage. Basically, automatic transmissions slip ALL the time, the lockup converter makes it act more like a real clutch. When lockup kicks in, some describe it like a shift into the overdrive gear you're not supposed to have. Makes the throttle more responsive because it's about as close to a 1:1 direct drive connection as you can get with an automatic, but if you let off the gas too much or give it too much gas, the solenoid will unlock the converter.

J-(Chicago)

Turns out that it was a regular Th350, and the sending unit was just some kind of new fangled Knock sensor. A Th350C lockup will have a 4 port plug like this one. I try to learn something new everyday.
Picture 2 looks like the thing that's on my trans.

joe_padavano

Newsflash: if your trans needs a "knock" sensor, you've got bigger problems. More likely that's a pressure switch for Transmission Controlled Spark. It would make contact in third to activate the TCS vacuum valve.

chivo80026

I got a th350 from a 1979 Cutlass would i be able to install it on my 84 cutlass even tough it dosent have a lockup solenoid like my stock th250 transmission?