I need some advice on tracking down a transmission problem please guys. My truck will not lock up in O/D unless I lift off the throttle and sometimes, it takes several attempts before it finally locks. I changed the oil (ATF+4) and filter but this did not affect the problem. Occasionally I also experience a reluctance for "D" and "R" to engage when starting off. When the truck is running there is NO slippage in the system and the temps are normal even towing a heavy load. This problem has only just started so, where do I start looking?

 

Did you ever get this fixed?

 

i would use a scan tool and see if the lockup solinoid is even getting the command to lockup in a timiley manner

 

No, this is the latest situation.

I took some advice and had the transmission scanned. I drove and the tech checked everything out with a Snap On scanner. He could not find any hard or soft codes and everything worked exactly as it should but, the TCC still did not lock up in overdrive unless I eased off the throttle. Interestingly, each day when I drive to work the TCC unlocks at exactly the same points in the journey, always when I'm rounding a left hand bend. These problems started after I changed the VP44. I did not disconnect the APPS/transmission cable but is it possible that, when I moved it out of the way, I did something to the cable which could cause these problems? There is absolutly no slip in any of the gears and all other shifts appear normal except occasionally, when selecting drive or reverse from stationary, when it sometimes takes a few seconds for engagement to happen. This occurs both when the transmission is hot and/or cold. Temperatures are normal when running. Any further ideas or suggestions please?

 

when you checked the fluid was the truck in park or neutral? if you checked it in park and it showed full your tranny is 1.5-2 quarts low on fluid. always check it in neutral with the tranny warm. also it prolly wouldn't hurt to do either the quick APPS reset by disconnecting your battery cables (just grounds on both batteries) let it sit for 30 min. or so. hook them back up, turn the ignition on, slowly press the accelerator pedal down to the floor, hesitate and slowly bring it back up the idle position. turn the ignition off, then crank the truck. see if that makes a difference. if not read this thread and there is a how to on a more in depth APPS reset/calibration.
https://www.dieselbombers.com/5-9l-2...s-i-bored.html

hope this helps.