Transmission Behavior

Hey all. I have the 2016 5.7 4WD. Love the truck in every way except for the transmission behavior.

I like how it operates when it's not warmed up... basically lets you coast when you're not on the gas. But once it comes up to operating temperature, the transmission then drags when you let off the gas instead of freewheeling or coasting like it does when it's cold. I know part of the mapping doesn't lock up the torque converter until it gets to operating temp... but this drag happens in gears 2-4 as well when it's warm.

Wondering if I could track down a tune to dial it in to my preference referencing the trans mapping when cold as a baseline and then just adding torque converter lockup in gears 5 and 6 as soon as it gets to op temp. Any insight would be greatly appreciated.

 

I would check ATF degradation counter. When TCM decides ATF is dud it changes shifting patterns to keep torque converter locked up as much as possible.

Also valve body has an on/off solenoid for coast clutch, it may be stuck in yours. But in that case you would see a transmission error.

 

I think someone on the forum (maybe) said that ~50k degradation score was fully trashed. Is that accurate?

 

Do a drain and fill. See what the oil looks like.

 

My degradation score is only 2750 and my fluid looked black as night. 38k miles, no towing. Hard to gauge from look alone.

 

I trust color over oxidation counter any day. A properly working transmission, with proper ATF cooling, almost never turns ATF brown or even black. I still keep d&f them regularly.

 

Yeah, I think I’ll do a drain and fill at 40k miles after seeing how dark mine looked during the cooler install.

 

WS turns dark fast. Or maybe Toyota transmissions turn the fluid dark fast.

 

Check fluids, then get a tune this will make a significant difference. Paging @JustDSM from OTT.

 

Maintenance first before trying to tune the trans.

If you have never done it, or have not done it it past 40-50k miles, trans drain and fill is in order. Do the diffs and xfer case while you are at it and lube your driveline zerks.