I didnt even know there was such a thing.. till I bought one thinking it was a standard th350 . It did not look right. with the plug in on the left side. and the marks MV4 .. what should I know about this style of tranny? Im reading about Lock Convertor.. what does it do , what makes it work? can the unit be used in a Traditional Ride. or move it on and find a Normal th350? Thanks..
It's a TH350 with a lockup torque converter. It was introduced in the late 70s, when they were looking for mileage, and they went to rearend gear ratios like 2.29...which made the torque converter slip when going 55 in high gear. If you don't connect it, it will work like a normal transmission. As long as you have a normal rearend gear, it should work fine. If you want to play with the lockup feature, you can find the wiring diagrams for how they were used originally, they had a vacuum switch and a brake switch, iirc. You could use a toggle switch, but you want to figure out some way to keep it from engaging at low vehicle speed.
Okay..Ill be using a Maverick 8 " rear I believe they are 2.73s. I should of done my homework prior.. oh well...it will bolt up the same as a normal 350 or glide? also.. drive shaft.. Im gathering there the same? are they not? the newer tech is hard to follow..
It's pretty much identical to the normal TH350. The torque converter is different. There is an electrical connector. Other than that, it's the same. also note that there was a TH250C which looks just like a 350C, but has a band adjuster bolt near the front of the transmission. The 250C is a lighter duty version of the 350C, it does not have the 2nd gear roller clutch and plate clutch, it has a heavy duty band instead of the normal intermediate overrun band.
What squirell said , for the lock up its sometimes easier to buy the premade kit as you get all the right stuff and the right directions at once , I like throwing in a extra cut off switch so when you drive around 45 mph the unit doesn't do the famous "converter hunting" of locking and unlocking which drives some people nuts from the surging it does and 2:73 is about as low as you want to go with a unit thats stays unlocked .
If the 350C/MV4 trans is in working condition I don't see any reason to not use it. At the right speed and throttle position a clutch in the convertor will lock-up and eliminate all internal slippage. Thr RPMs will drop a bit, fuel mileage should go up a bit and the AT fluid temps might drop a skosh. But it does take a little extra wiring and some vacuum hose to make it all work right. In production there was a pressure switch on the trans that sensed vehicle speed. And it was wired in to a manifold vacuum sensor that kind of sensed throttle position, or more accurately, engine load. All this was wired up to plug into a connector on the trans where it could actuate a solenoid that routed fluid to the clutch in the torque convertor. With the throttle in a cruising position and enough manifold vacuum, and enough pressure at the vehicle speed switch, the circuit closes and the convertor locks up. And if you want to get fancy you can wire a rocker switch into the circuit and switch everything on and off from inside the car. And yeah... There was a circuit thru the brake lamp switch too, like Squirrel said. It works like the switch that disengages your cruise control when you step on the brakes.
Thanks... one other question.. does it have to be plugged in, or can I use this transmission without being plugged in? just hook everything up and go? except the electric plugin?
You can use it without the electric stuff connected. The converter will not lock up. It will behave mostly like a normal TH350.
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