TH125 (non-H-body) 3-speed transmission troubles

[barebonesracecars]

This is an '88 Sunbird (FWD). I don't have alot of automatic trans experience, so I could use some advice.

The car sat for about a year. After getting it running again, I changed the trans oil and filter. Seemed to shift fine on several short trips, although it probably wasn't completely up to temperature.

Then went for a longer drive, and after about 30 miles it didn't act like it was downshifting at stoplights properly. Eventually, I came to a stop and it stuck in Drive and died. Several restarts and moving the shifter through the gears failed to unlock it at first, but eventually it did.

Made it home then, but it still acted the same...it also upshifted too quickly, lugging the engine.

I have now adjusted the TV cable as per a Haynes manual. It seemed to be moving freely as it should, not broken, and the adjustment appeared to take it back to the same spot. The shifter cable seems fine; goes firmly into all gears.

Is this all I can do externally? What else may be causing the problem?

Thanks guys.

[therick215]

I would say it is the torque converter clutch soleniod is sticking on and keeping the coverter locked up. You can unplug it and it won't lock up. Then drive the car and see if stalls. The check engine light may come on does on some and not on others. Here is a pic of where it is located. Rick

[therick215]

I'm sorry open the hood and the plug is on the side of the trans. If I remember it is a gray connector. Rick

[heinz057]

souds like the lock up converter. what you can do is on the front of the trans is a square 4wire plug you can un plug that to eliminate the lock up.

[starfire383]

Vote #3 for lockup converter staying locked.

[barebonesracecars]

Ok, I'll try that.

Is that one of those things that can't be left unplugged without ruining the converter?

If so, and that is the problem, can it be replaced easily with the side cover off?

[heinz057]

yes. not to bad of a job

[barebonesracecars]

Great. Sounds like just a bolt-and-unplug deal. Wasn't sure if it was a complete trans tear-down.

I'll call NAPA after I try that and see if they can get one.

Thanks!

[HI WINDING MONZA]

Reid, ,I had the same thing happen on the Citation. When I bought it , it was unplugged so I plugged it in for the ride home. When I almost got home , the car shut off at a stoplight just like you said. I unplugged it again and never had problem again. We put about 2000 miles on it since with no trans problems. Doug in Az

[barebonesracecars]

That's good to hear. I know I've heard that 200R4's and 700R4's can't be run that way, or with mis-adjusted TV cables. Just wondered what would happen if I run this one that way.

[starfire383]

The converter can stick for 2 reasons, the TCC solenoid needs replaced which can be replaced with the pan off most transmissions. Or it's stuck because the converter is shot.

Given that a junkyard trans for that car must be about $100, I'd unplug it and run it to death. I've put 15K on a lockup TH350 that was unplugged, and removed it for an overdrive conversion, not because it was a problem.

I too have heard that it's hard on the 2004r and 700r4 to run them with the converter unplugged. But then again, you're supposed to run them in 3rd gear when towing, and the converter won't lock in 3rd gear.

[barebonesracecars]

It seems to drive just fine with the TCC unplugged, so I guess I'll do that. Seems to me that the converter must be ok.

Thanks for the advice.

[therick215]

It won't hurt running it unplugged. Rick

[barebonesracecars]

Thanks again for all the replies. I drove it to work last night with the TCC unplugged....seemed fine.

So what is the worst that will happen? Lower mileage?

Mileage is the reason I bought the thing....my Ford gasahog truck is killing me driving 30 miles round trip to work.

(If any Ford engineers are reading this, you !@#$%s ought to be ashamed of yourselves. This is a 2004 with 3:73 gears...and getting 15 mpg. My dad's 2002 Silverado with 4:10 gears gets almost 20 mpg.)

[therick215]

I don't think you will notice a difference in mileage with it unplugged.I know what you are saying about Ford and their mileage. Dodge trucks aren't much better in the mileage but I don't look at mpg on trucks. I want it to pull and carry a load.
My wife's Jeep Grand Cherokee 318 auto 3:73 full time 4WD she gets 21 mpg and I get 19.5 when I drive it wonder why. Rick