Hey everyone, I have been noticing some quirks with this new truck. When it still cold in the morning, everything seems to work fine as far as shifting goes and the TC locks up around 45-50mph. But after a few miles and when things start getting warmed up, it seems that the torque converter starts locking up earlier. I have read here and a couple other sites for almost two weeks trying to figure out what might be the cause, but it seems that most threads are related to no OD or lock up. When cruising or under light acceleration, I've had it lock up as early as 35mph which will then cause the truck to buck. Also, once warmed up it seems like there are times when holding steady throttle but losing speed, for instance going up a long shallow grade, the torque converter won't unlock which again causes bucking at around 35-40mph. If I let off or put my foot into it, of course the TC then unlocks.

As an aside, will the converter lock up in 3rd gear if I have the OD off button activated? I've done quite a few tests driving around the neighborhood and counted the shifts, and I get the 1-2-3 and then after a few seconds of light throttle a little 'bump' and the rpm's drop slightly.

I have "adjusted" the tps as much as I could to the specs on this site. Initially, the low end was .41, now it's at 1.02 at the low end. I will note that this did not affect the low speed TC lockup problem. But it did make OD work much better.

So any ideas? Is this how it's supposed to work? Live with it?

Thank you in advance.

 

Any transmission people out there? What about VSS? I don't know if it's tied into OD lockup or not.