91 explorer transmission locking clutch

[thescarbs]

1991 Explorer transmission locking converter does not always engage. Some times it will work if I increase the speed and let off on the gas. It usually enguages at about 55 mph and RPM drop abut 500 RPM,
IS there A cheap fixes. Most of the time it works perfect. Any help
thescarbs@hotmail.com

 

[asp84]

Have the same problem in my 91 X, The torque comverter lockup does not engage. (slips in and out some times.) There is sometimes a fix for this. Try replacing your Voltage regulator and throttle position sensor. The Torque converter is electronically controlled (I believe) and will not lock up if there is a bad voltage signal from the voltage regulator on the Alternator. (I have not tried this remedy yet on my Explorer, but have it heard it works) (my bat voltage guage seems to read over 18 volts!

Thanks,
AL

 

[MrShorty]

The Torque converter clutch (TCC) is computer controlled. Here's how it works. In 3rd or 4th gear with the TCC disengaged, the TCC solenoid circuit is open (no current flowing). When the computer decides the time is right using information from the various engine sensors (including throttle position as mentioned, engine coolant temperature, vehicle speed, battery voltage, etc), it closes the circuit so that current can flow through the solenoid. This moves a valve in the transmission which causes the TCC to hydraulically engage.
Because your problem is intermittent, It's probably a bad sensor or a bad connection in one of their circuits, as opposed to a problem in the transmission. The real trouble will be finding which sensor/circuit is at fault.

 

[jimmiecakes]

my bat voltage guage seems to read over 18 volts!

You may want to fix that before you have to buy a battery too.

 

[SteveVB]

Pull codes see if anything comes up, that would be the first thing- and is always the first thing to do with any prob on the Explorer.

Also the lock up is inhibited during certain types of driving, so if you have a vac leak or a bad temp sender, TPS, etc it could prevent it from locking up

one is wwhen the engine is cold , less than 150Deg , or hot over 250deg- aproximate temps I cant remember.

2) with brakes applied, or 3)during certain throttle openings. Closed, quick open or close, or WOT.

If you check the codes, the TPS, and the Brake switch that sould cover these situations.

Could be the solenoid in the trans, or maybe some debris/ gunk preventing the valve from operating properly, both would require removing the trans pan to get to them.

The last thing I would check would be the TC itself which requires trans removal.

good luck

 

[MrShorty]

TCC solenoid valve

Has anyone cleaned the valve body that controls the TCC? I would like to clean mine, but I'm not sure how hard it is. I read in a manual about a Z fitting or something that is easy to bend when removing and replacing the valve. Anybody worked on that valve body who can tell me how hard it is to do?