Converter Lock UP

[HowieE]

This statement appears in a description of the Ford 5R110W transmission. While the statement does not state this is during Tow Haul Mode it is in the discussion of that mode.

The torque converter clutch will lock up at a lower vehicle speed for a given accelerator pedal position to provide improved transmission cooling. It will also stay locked longer on deceleration to provide engine braking. Engine braking is also provided on deceleration through the coast clutch.

Can I take that to mean the converter can be locked in any other gear than OD and at any speed below 65 mph while in THM? I ask this because I have noticed the trans does remain cool while pulling a hill in lower gears. I had just assumed the converter was unlocked once a downshift had taken place.

 

[snicklas]

I do beleve in THM the converter does stay locked up more. This is how it accomplishes the compression braking and keeping the transmission cooler. Alot of the heat that is built up in an automatic transmission is from the TC slipping. Keeping it locked more will help to cool the transmission and not create the heat in the slipping converter. I can tell a huge difference in transmission behavior between THM and normal. I have even used THM on the hills and mountains unloaded and it make a huge difference....... On a trip to NC across I-40 going down the mountains I could hold a very steady speed and was using almost no fuel at the momentum was keeping the engine moving.... you could hear the clatter from the injectors go away as they were not fueling....... I know the transmissioin and converter are all computer controlled.... it may unlock momentairly during a downshift but I can tell it is lock back in, in the next lower gear...... you really feel the difference when towing while the load is "pushing" the truck along. Another thing the 5R100 (Torqshift) transmission will do in normal mode is control or "split" the gear ratios using converter lockup. On a moderate aceleration I have counted 6 "gears" one if which is the converter lockup, and not a gear change. I though something was wrong with my truck till I read up on the transmission more and found that was normal.

 

[wrightracing.net]

Lockup module

Has anyone used one of those transmission modules that locks the torque converter clutch's up at slower speeds to help keep the trans cooler on slow up hills under heavy loads for long periods of time. I have one on order and hope it helps with cooling. I have done everything under the sun, thus far. Upgraded transmission shift kit, $1500 billit torque converter, huge tranny cooler along with OEM cooler, and it still got hot in the dunes on my last desert trip. Yes I take my 1999 F350 Diesel superduty in the dunes.

In the pictures Auto 4wd did not engage, I had to manuel engage the hubs, I love that about the superduy, great backup feature for the 4wd.