Torque converter lock up while towing.

[hjs123]

Does any one know how I can get the converter on my 2005 4.0 L 4wd explorer to stay locked up while towing my 4000 lb travel trailer? I run with the OD turned off at about 2400 rpm at 55 - 60 mph but the slightest change in throttle position causes the converter to unlock (making heat in the trans and wasting fuel). Is there a solenoid the could be externally powered through a switch to keep the converter locked up? (Of course teh switch would have to turned off at lower speeds and when stopping)
Any thoughts or suggestions are appreciated.

Is there aneed for an external trans cooler on this vehicle?

Thanks

 

[BrooklynBay]

Welcome to this forum! I've moved your thread to the transmission section. Your TCC solenoid is modulated, so it's always varying at different levels of being locked. The computer controls the level of slippage. The older A4LD was either completely on or completely off. An external cooler is always recommended if you tow.