I can't figure out if my torque converter is locking up and staying locked sometimes when I drive. There's only one plug that goes into the transmission (4-prong plug). Can I unplug this plug and drive around okay? I would assume that unplugging this plug would disable the ability of the torque converter to lockup. Thanks.

700R4 with stock rebuilt torque converter, btw

 

Unplugging the connector will prevent the TCC from locking up. Don't go on any long trips on the highway without it.

 

For what exact reason other than economy??

 

The torque converter clutch reduces heat buildup in the torque converter. Heat is one of the leading destroyers of transmissions.

 

True.......runnin a high stall Lock-up TC with a Tranny cooler

 

From what I have seen on this board, our 700R4 transmissions (especially the earlier units) are not too great. They cannot take the extra heat created by NOT locking the converter during highway driving. I have been using Castrol full-synthetic ATF, and rarely permit the converter to lock. The fluid seems unburned. The filter and pan remain clean. The pan gets dropped every year. I have only the stock in-the-radiator cooler. Excuse me while I knock on wood.

 

I had my 84 700R4 overhauled several years ago and I had them install a non-lockup torque converter. I bought a kit from Art Carr that rerouts the oil flow in the tranney so it won't burn up. I checked transmission oil temps and they run about the same as eng. coolent temps. The driveabilty of the trans is awsome. No lock, unlock, lock BS.

Auggie

 

Mines on a switch for highway use....also I think B&M makes a kit that only alows your TC lock-up on the highway only in OD. I can always remember the button, don't need it automatic I guess....

 

That's a characteristic of all automatic overdrive transmissions, not just the 700R4.

 

Well, as long as you are the only driver??

Auggie

 

I assume you are talking to me.......

This is more of a drag car.....drive it myself only to track and around town a bit......

 

Cool!

Auggie

 

I have a 1989 formula 350, bone stock with 66k miles. The car has been well cared for and had some periods of extended non-use over the years but always in dry clean storage.

Problem: The car acts like the torque converter is always in lock up. Applying the brakes, the car seems like it is still under load, and after coming to a stop and releasing the brakes, it will go forward and achieve maybe 10 mph without pressing on the accelerator.

My other cars will at best, just creep forward slightly from a stop without pressing the accelerator.

The car also sometimes idles a little high (1100 rpm or so) but a quick blip of the throttle brings it back down.

I have used mass flow cleaner, cleaned the throttlebody, and removed and cleaned the IAR valve (which was somewhat carboned up) but moves freely. I was gentle with it.

The GM shops and repair shops in general don't seem to know much about these cars.
It also sometimes starts hard when warm or cold. Otherwise, runs fine. Any help from my fellow F body friends? Thanks!

Jeff bowtieguy68@yahoo.com

 

Your throttle shafts are worn and the throttle body needs to be rebuilt.

 

Interesting idea. Thanks for the reply and advice. I will surly look into it. However, even at normal idle speed, this problem is present. I would assume that with worn throttle parts, it would be sucking air and raise the idle speed and the problem would be there only under high idle? I am also going to try the driving lock/unlock test by holding a steady speed and then tapping the brakes looking for the tach to raise a couple hundred rpm by unlocking the converter. My other cars pass this test. I just recently remembered this . Again,, thank you for your advice!