07 trans ?

[scott degroot]

I've got an 07, 4.0, 4x2 and when you are doing around 40-45 mph and the torque converter locks up(that's what it seems like to me) the truck picks up a vibration with steady light throttle applied, kind of like you are lightly lugging a manual trans. If you apply steady light throttle it goes away around 50 mph. The part that is really annoying is that this is the speed of most of my in town driving is done at and sometimes it is very bad (the wife even commented on it) Before I run off to the dealer has anybody else experienced this?

 

[Tom Schindler]

I would say possibly the dealer needs to flash the ECU. Could it be the converter locking and then unlocking really fast?





Tom

 

[scott degroot]

The converter is definetely locking up, but it is not cycling between locked and unlocked. It's exactly like the motor has to much load on it for the given engine speed, just like you are lugging a stick shift.

 

[Tom Schindler]

Then it is locking up too soon.





Tom

 

[EddieS'04]

40 to 45 mph is where the OD (5th gear comes in). Are you shure your not having a problem with that. The converter locks up at higher speed. I think the converter on my '04 will lockup when I cruise at a steady 35 to 38 mph. Otherwise as long as Iam accelerating the converter doesnt lockup until after it shifts to OD at a steady highway speed.

I have had a few times when cruising over 40 in OD that it failed to downshift to 4th gear when accelerating. I had to push the Throttle more than normal to get the down shift. No vibration though.

Diconnect the - battery cable for 15 minutes to reset the TCM. Then take it out and drive it the way you want it to shift, so it will relearn. If that yeilds no change, use the warrenty..

 

[scott degroot]

I'm pretty sure that it's the lock up converter, I can be driving down the road at steady throttle with the problem happening and without letting my foot off of the gas just barely touch the brakes, not enough to actually brake the truck, and you can feel the converter unlock(rpms go up about 300 rpm) and the vibration/lugging goes away. If I accelerate I can feel the truck come out of OD so I don't think it's and overdrive issue.