Auto transmission swap

Hey Billski and M1Dadio, I'd like to see how you hooked up the TV cable to your carb. I've tried two homemade brackets that are very close to working but then I find that the cable connector interferes with a spring or the choke or something.

And did you go with the vacuum switch too? My instructions from Bowtie Overdrive don't use that. They just have you tap into the brake light wire for disengaging the TCC.

And did you both use a cable for shifting? I'm trying to stick with my original linkage as much as possible since it came with an automatic.

Vanagain:

My TV cable is all factory on a TPI engine. I only diched the cruise control and changed the throtle cable.
BEFORE


AFTER


You can use your factory shifter as I did, with a cable. I used the old three speed linkage in the colum but it has no gate or lock out which makes it dangourous. I am looking for the auto colum for mine.

You can use your auto colum, you will need to modify it so it will provide the extra shift position for low 1. I think you just need to file it a bit. When you add the cable you need to get the levers right length to make it be in the right gear at the right time for the shifter.

Mine looks like this. Sorry this is the only picture I have.



There are quite a number of aftermarket kits to control these 700R4 with the TCC units. As I have been doing a pile of research to figure out my trany issuse I have discovered they are all very simple just not the same.

Probobly the best trany conversion kit for a stand alone 700R4 is the one were you have to remove the pan and re-configue the wireing inside the transmision.

I say this because you may buy a kit that adds a vacuum switch or a relay operated off a brake light wire or a dash togle switch but all of these work only if the inside of the trany is wiriered in the way that works with that kit. I have the GM manual for my set up. In it there are nine different wiring configurations, some ground the TCC solinoid inside the trany and some outside. Inside the trany There could be up to about four different presure switches and 3 temp switches that may, or may not, be in you 700R4 valve body and the TCC solinoid. I am told by one who knows that there is actiually 27 different combonations of these used with different wire layouts. Right from one that uses none, only the solinoid and one TCC possative wire coming out of the trany all the way to one that usses them all and has four wires coming out, and everthing othe combo in between.

So I don't see how just adding an external kit can possibly work for all 700R4 transmisions.

This is the problem with my factory set up shift problems. The only control my computer has over the trany is to turn the TCC on or off by switching the ground wire open or closed. But the donner car engine computer set up is 1988 and it had a 1992 trany installed at some point which has the wrong internal wiring / switches. All I have to do is pull the pan and change the wiring to what its suposed to be and possibly add or subtrach some switches, Easy to do You just need to know what to change it too.

Thanks for the long description about the wiring options! Boy, you'd think transplanting the whole drivetrain like you did would insure that the 700R4 would work properly, but the year mismatch on the tranny didn't help, and it's used to having a computer. But as you say, installing the internal wiring mod is all that is needed.

My Bowtie Overdrive 700R4 came with their wiring kit already installed inside. I only use one wire in the plug (the A pin) to 12V when the key is on. Then a wire is tapped into the brake light circuit and ran to a relay. When you hit the brakes, the relay cuts off the 12V to pin A and disengages the overdrive lock. Optionally, you can add the vacuum switch in the wire going to pin A which provides another circumstance to cut the power to the OD, when the engine vacuum is low (throttle goes low or to idle). Plus you can add a manual switch with a wire to pin D to lock in the overdrive in 2nd or 3rd gear for towing. They have you wire it so hitting the brakes still disengages the OD.

Here's Bowtie's web page where they sell the internal kit and two different external wiring kits:

http://700r4.com/tech/tcc/index.shtml

Follow their links to see their instructions and wiring diagrams.

A friend of ours here in SD installed the internal kit in about 15 minutes. It's not as scary as it looks. And the relay setup should be just as fast. It is mostly under the dash: Ignition wire from the fuse box, crimp their splice into the brake light wire and then run a long wire back to the tranny. I've read thru these instructions many times and now I'm finally at a point where I can hook this up in my van! I should just stop typing and go do it!!

Vanagain is correct. That wiring inside the 700R4 is very simple when you look into it. I would encourage anybody who wants a 700r4 or the 200 to go for it. Remove the pan and install it.

My 700r4 wiring being controlled by the computer (sounds complicated) is really just as simple. Mine has the "A" 12volt suply wire interupted by a brake light switch just like the aftermarket kit. The only difference in mine is my 4rth gear switch sends a ground to the computer to tell it when I'm in forth and then the computer simply makes or breaks the ground to the solinoid. Thats it! Really.

It only gets intimidating and confusing when you don't know whats inside the trans for wiring and switches and its doing every thing except what any one expects it to be doing. You then think you messed it up on the outside. Some transmisions have thermal switches and 3rd gear switches and all kinds of different wiring arangments to match whatever computer they were designed to go with. But they all are pretty much the same when you remove whats there and install the simple stand alone aftermarket kit. By "stand alone I mean only needs a brake light trigar and maybe a dash togle switch if you want. This is what you want when adding the trans to any vehicle that didn't previously have a 700r4. Again ther are about 32 posible factory internal wiring posabilities. You have to know whats in there to make it work right.

So go for it , If yours dosn't work right, don't be shy , open your trans pan and see what you have in there.That is all the problem with mine, wrong internal wiring.

And like he said, 15 minutes to change it. Not counting the clean up of the oil spill. LOL.

M1D

I just took out my 250 yesterday because my buddy has a mild stock car 350 with about 400 Hp and around 5k on it ready to sell to me. A bonus was I could get it turn key with everything, (except the rad which is too big), including his tranny.

I don't think I have ever heard about anyone who has use the automatic turbo 400 transmission. I was just wondering if there is a particular reason for that.

Let me know. I'm pulling the other motor and tranny from his truck tomorrow to install.

Heavy

I have a 200-4R and did the wiring conversion. Very simple. Cable ajusting is going to be less than fun and still looking at mounting ideas...

If I remember right the 200R4 is the same lengh as a PG ,so you dont have to cut DS. & I "think its a 4(??) speed auto with OD lock up. I don''t think they made(used) as many of these as the 700r4?? I know sombody else knows alot more that I??

Savage, that is the reason I got the 200-4R so I wouldn't have to re-do the drive shaft. And the 200 will hold up far better than the 700.

Scott, I only paid $200 for mine off Craigslist. $35 for a new filter/gasket and I think $30 for the lockout wiring conversion (Very Simple)...

Dan

I found a "Rebuilt 700 R 4 long shaft, low miles" transmission listed for $200. Not sure what the long shaft brings it to in length, on this chart there is only one length for the 700..? At $200 I would still do OK even if I ended up getting it rebuilt.

Any of you know the length difference between the long and the short?

Good reference guide pulled from: http://www.transmissionplanet.com

Scott, You might want to ask Donivan on this. I believe he had figured it out a while back.

Dan

Just thought I would put some info in here for those that are interested. I recently put a 4.3L V6 and a 700r4 in my 69 108 and was able to use the original drive shaft. I remember when I was looking for information on doing a trans swap everyone said that the 700r4 was longer then the original transmission and that I would have to cut the drive shaft or get a new one. Well I guess the shorter engine made up for it since I didnt have to do any of that.

Good to know.

Scott wrote:Here's a guys page that explains what it took to switch from a PG to a 700r4. Not a van, but some good info..

Those of you on here that have already done the swap may agree or disagree with this guy.

http://home.tiscali.nl/rusty66/pg_700R4.html

Think this guy has a few issues... And needs to do a bit more research.

I do like the "New Constant Pressure Valve Body" link. Makes for good reading and thought provoking.