o No: The plan is to replace the TH350 behind my '77 231 oddfire V6 with a stock 200 R4 from an 87 Olds Cutlass. I have a 3:55 geared differential. My concern is the lock-up converter, since the engine is carbureted and no computer controls. Summit Racing offers a wiring harness for this, ( part #PRF-60110) but it is a bit pricy.:rant: Is there another way of doing this using parts store pieces. I don't want to use a toggle switch, as I don't trust myself to switch it on/off at the proper times.:Brow: Thanks in advance for any help, I will be checking back.:TU:
There are a variety of ways to handle this, but I was also surprised that they all seem to be rather expensive. The logic is fairly specific, so I don't think it's something you want to just piece together (unless you want to tackle that as a project of its own). -Bob C.
If you want to have it controlled automatically... then it'll cost you some money. If you just want to lock/unlock it manually... it can be done on the cheap. Just don't forget to wire in the brake pedal cut off switch:Brow: I plan on just doing it with a toggle switch when I put the 350 infront of my 200r4. no need for that fancy vacum switch. I think that summitt kit will only lock it in 4th gear anyway. I may want to lock mine earlier.
Here's everything you need at this place. They're who I used and I was very happy. Don't forget the linkage part to go on the carb so you can hook up the TV cable along with the new throttle/TV cable bracket. http://www.transmissioncenter.net/200-4R.htm
I've posted this before and no one ever had a comment. Maybe it's too easy? You can have the converter lockup automatically after it shifts into 4th gear. All you need is one cheap simple pressure switch that you can buy online at GM parts direct and get 12volts to the trans. Absolutely nothing else is needed. Mine has been this way since 2004 and I love it. I don't see the need for any other way of doing this except for a guy with a V6 like you. You may want a vacuum switch so the converter will unlock under a medium heavy load because your 6 cyl might lug in 4th and the 200 RPM you'll gain with the converter unlocked may help you go up a hill on the highway. If you give it enough throttle it's going to downshift into 3rd and unlock anyway so this is a very specific situation. If you have a decent 350 or 455, the engine has enough torque that you do not need the vacuum switch. Why do people go through all the trouble with manual switches and brake and vacuum switches? For performance builds, you're using 4th gear for cruising and that's the perfect time to lock the converter. If you're racing, you're not in 4th and the converter is unlocked just like you want it. Here's the diagram and part number for the switch. 2004-R 4th gear lockup
I also have a manual switch for my lockup. I mounted the toggle switch in my glove box in the hole where the light bulb shines through. And it is VERY easy to install. Just a pressure switch on the passenger side of the trans and two wires to hook up. I like the manual because my car shifts into 4th at about 45 mph or so and then goes almost immediately into lockup. Now the car is really lugging around at like 1100 rpms. It's just too low for me. So I just engage it when I'm on the highway.
mine will shift into 4th early too if I let it. I leave the trans in 3rd unless I'm going over 60 MPH. It acts just like a 3 speed. Have you ever tried that?
:TU: Thanks for the responses. You helped me make up my mind. I,ve decided to spend the money and do it right the first time!!!
Hey Andy - What do you do outside the trans? Are you only providing 12v to the connector and not using any computer, etc? I wonder if the pressure switch can take the current required for the solenoid. Also, it looks like you could do the same thing with a jumper outside the trans and not have to modify the insides. Comment? - Bill - Bill
My 200-R4 has the kit that locks the converter in 4th gear only. Its OK but I don't care for the fact that it locks up immediately after shifting into 4th. I was also told that driving without the lock feature working produces excessive heat.o No: I'm not sure about this but if it does, driving in 3rd to avoid the lockup and lugging in 4th can't be good. Bob H.
All I have on my 2004R trans is the TV cable and one wire to the plug on the side of the trans. Nothing else. That pressure switch has no trouble energizing the solenoid as that's what is was designed to do. There's no mods to the inside of the trans. They came with a pressure switch. All you do is thread in the correct switch, normally open, into the valve body. I don't think you can do that on the outside of the trans because the switch needs to see pressure when it shifts into 4th and there's nowhere on the case that I know of that can do that. I guess is depends on your combo and how you use it. If I'm in the city, I'm under 55MPH, it's in 3rd, converter unlocked and it's stop light to stop light. If I get on the highway, I'm going over 60, it's in OD, the converter is locked and no lugging. If I drove 55 on the highway, my setup wouldn't work.
It looks like the splice is not "waterproof" - you just used a crimp connector??? I'm surprised the tranny fluid doesn't affect it at all? - Bill
bill, you mean my blue connector? I didn't worry about sealing it when I saw the factory connector on the switch being completely bare. Oil isn't a good conductor of electricity. I did nothing radical here. This is just a slight mod of some factory parts. The trans in the pic came from an 85 Olds if I remember right. It had the wiring and the pressure switch from the factory. The factory switch was normally closed so I changed it out to a normally open switch and moved one wire. That was all that had to be done inside the pan to make the lockup work.
Unshielded connections inside the case are common. My ST400 detent and variable pitch wiring is the same, and is more intact than I am after 41 years! Devon
