4R44E "chugging" in lockup

[Chris_North]

Hello again. I have a 98 Ranger 3.0, which from what I understand means I have a 4R44E transmission with about 140k miles on it. I recently replaced the heads on my engine as they head a few bad valves. Prior to replacing the heads, at speeds greater than 40-45 MPH my whole truck would shake really hard when accelerating under load (ie, anything but downhill) until it downshifted. I originally thought this was just the engine causing this problem, but apparently not.

With the engine now back to as close to 100% as it's going to get I no longer get a hard shaking, but a slight bucking/chugging under more or less the same condition. A little experimentation and troubleshooting has led me to the TCC. I put in one of those lockup switches, and found it to definitely be only during lockup. With OD off, I do not notice anything. Does disabling OD also disable 3rd gear lockup? I'm not sure whether I only notice it in OD, or if really is limited to OD gear.

I also tried preventing the TCC from engaging by leaving the signal wire disconnected altogether, but this turned out to be not a good idea as it created a DTC, caused the OD light to flash, prevented the trans from going into OD, and made it shift very hard. Is fourth gear/OD even possible without lockup?


My main question being: Is it possible that I could fix this by replacing the TCC solenoid? If so, is there any way to be sure before doing so? If not, what else should I look into? I am one of those people that believe that if you set your mind to something you can accomplish anything, but rebuilding a trans is not something I'm up to at this time. I don't have the funds to replace or have it rebuilt currently either, so I'm hoping it might be something simple. This has almost never been my luck in the past but I am still hopeful.

Thanks in advance.

 

[Chris_North]

I've also noticed that with that bypass switch enabled (to manually control lockup) I will stall the truck when moving from park or neutral to drive or reverse. I was reading that the valve body should prevent lockup from occuring in 1st or 2nd gear. Unless I misunderstood and this was only for the 4rLD or whatever the earlier trans was. I'm not sure if this is another symptom or issue...