200-4R Connector

[samsquanch]

Hello. I just installed the transmission in my car. Went to plug in the connector and it wouldn't go in. My car has a 4 prong connector. The one on the transmission only has 3 prongs one is blank. The guide slots on the car side are different as well. Can anyone help me out with this one? Do I need to swap the harness in the transmission? Is it possible the transmission is setup for a different car?

 

[blackazz]

Can you give us a little bit more information. What year is the car? 84/85-86/87
Is it a brf,brQ,or another 200r4.

 

[samsquanch]

Car is an 86. Plate on Original transmission brf. No plate on the new one.

 

[samsquanch]

About to pull the pans and see where the wire goes. Possibly swap the harness.

Documents that were with the new one specified it was built for a gn no idea other then that.

 

[samsquanch]

Ok pulled the pan. New transmission doesn't have pressure switch on the rear of the vb.

 

[samsquanch]

Now the question is what's that switch for? What's the difference between the two?

 

[samsquanch]

I think I figured it out. It's a 3rd gear switch. Now the question is does the car sense that switch and control lockup when shifting from 4th? I really don't want to drop this transmission again, at least not for a while.

 

[pacecarta]

stock ecm uses 3rd and 4th gear switches to signal the ecm to allow lockup... and to drop timing and reduce boost in higher gears

besides needing the 3rd and 4th switches and the correct harness the brf trans (or trans modified for a GN use)
also needs the correct combination of governor gear and speedometer gear so speedometer output to the ecm is correct to allow 47mph lockup
as well as correct governor weighting to allow the trans to shift correctly when running the GN 3.42 gear

 

[samsquanch]

I was reading about a few cars that didn't have the 3rd switch installed, and had the extra wire. They mentioned it would still lockup in 4th.

The plan was to install this one and have the other rebuilt as a spare. Far as I know the converter self destructed and dirtied up the transmission.

All the paperwork I have for this transmission says it's for a gn. I'm guessing it is for an older model, but have no idea at this point.

Main goal is to get the car to move under its own power. I don't really plan on driving it for a while. Still lots to sort out.

With the 4th switch only would I be able to drive it and watch the throttle in 3rd gear to prevent overboost? Will it achieve lockup with just the 4th switch?

 

[gsgns4me]

Here's some wiring diagrams that might help. I was thinking all the case connectors were the same, though. Yours should plug up even with the blank in the case harness.

 

[THensley]

Looks like someone didn't buy a trans from a reputable Turbo Buick transmission builder.
This is just his first problem to get it to work.

 

[samsquanch]

Hard to see in the pictures, but there are slots on the car side connector. The round ends. They are 90 degrees off on the transmission. Earlier pulled the pans off both. Wiring is the same minus the 3rd gear wire. I might mod my connector until I find another one, or just wait. Im not going fast for a while. Even if this transmission is fine. Still need to sort the brakes out, as they haven't been used in over 20 years.

As far as reputable Buick transmission builder I have no idea. It was purchased from an add in the back of a magazine advertising grand national performance transmissions. But that was sometime in the early 2000s. There were a bunch of handwritten letters in the box from the builder stating enjoy your gn transmission, setup and adjustments and so on. Guys name was John Kosak I believe.

 

[Chuck Leeper]

I was reading about a few cars that didn't have the 3rd switch installed, and had the extra wire. They mentioned it would still lockup in 4th.

The plan was to install this one and have the other rebuilt as a spare. Far as I know the converter self destructed and dirtied up the transmission.

All the paperwork I have for this transmission says it's for a gn. I'm guessing it is for an older model, but have no idea at this point.

Main goal is to get the car to move under its own power. I don't really plan on driving it for a while. Still lots to sort out.

With the 4th switch only would I be able to drive it and watch the throttle in 3rd gear to prevent overboost? Will it achieve lockup with just the 4th switch?

 

[Chuck Leeper]

"the plan was to install this one and have the other rebuilt as a spare. Far as I know the converter self destructed and dirtied up the transmission."
Backwards plan...
IF the BRF is really a BRF, you best not let someone "exchange it".
Too many differences in that one and the one you've put in the car.

 

[samsquanch]

Turns out it is a 700r4 connector. So car side will be replaced. Original connector about 1/2" if wire exposed at the connector so it needs replaced anyway.

I'm not entirely sure why this is a backwards plan. If the car gets rolling with the new transmission I dont see the problem. The original needs to be repaired anyway. Nothing is getting exchanged, I have two transmissions.

 

[wdxwrx]

Just a little FYI from my experience.
I had an original BRF transmission in my '86 T-Type that was given a performance build in the 90's.
It shifts great. Recently I replaced it with a trans built by Bison because I'm replacing the engine also built by Bison.
I recently replaced the 305 with a 350 in my '88 Monte SS. Even though the Monte has low (24k) miles it shifted really soft.
I installed the trans from the T-Type in the Monte. After fooling with the governor and governor gear I got it to shift perfectly.
Now to the point. The trans connector on the Monte harness has different notches in it and won't plug into the BRF trans.
Because I decided to eliminate the entire computer control on the Monte, I'm not plugging anything into the trans.
This worked for me. However, going the other way around, installing a Monte trans (or most likely any non TR trans) to a TR, wouldn't work because the TR computer requires additional info from the transmission.
In a nutshell. A TR transmission is a very unique unit.
Folks that have more knowledge than me can tell us what other transmissions are interchangeable with the 86-87 turbo Regal.
I'm just saying even a late model Non-turbo G-body 2004R and a late model TR 2004R have different electrical connectors.

 

[samsquanch]

Well this transmission is a go. I'm told it will work fine for my purposes at least until the other is built. Reverse and 1st are working good. The car moves under its own power after 23 years.