Every now and then the torque converter will not lock. Usually does it (or doesn't) after/during going down the highway. I'm pretty sure it is the converter cuz if I hit the OD button RPMs shoot up like normal. Hit it again, they go back down. This tells me it's not OD.

Now 9 out of 10 times it will lock like normal if I shift to neutral, then back to drive. Sometimes it'll start working on its own, but usually not, even if I come to a stop. For it to be normal I either have to shift to neutral or shut the truck off.

There are no codes showing for this. Any thoughts?

 

Mine was doing something similar. it would go on and off and my rpms would bounce around a little, like a couple hundred rpms while on the highway. Not sure if it's the same as what you are experiencing, but I had no codes. One day on the highway my tranny temp light came on and soon after my converter took a dump and my shifting went haywire. I ended up needing to get my tranny rebuilt. If I were you I would find a tranny shop or 2 that will give you free estimates and see what they say. Might save you some money by replacing the converter before it pukes and possibly screws up your tranny.

good luck-

 

Mine will unlock and stay that way. Sometimes if I shift to neutral it will lock up, sometimes not. It hasn't done it around town, only on the highway. But, if it does "act up", it will stay that way around town.

 

TC shouldn't lock below 45 mph. If it isn't engaging, are you getting any codes??

 

No codes. I live "in the country" so most of my in town driving has 40-55 mph speed limits.

If it doesn't lock, and I come to a stop sign, start goin again, I can speed up to whatever speed I want and it will not lock.

BUT, IIRC, TC would lock and OD would engauge between 40 and 45 mph. Which I contribute to it not being exact science and my speedo being off aprox. 3 mph.

I should add this has been going on for a couple months now, it just seems to be getting more frequent.

 

If the pcm commands tcc lock, and doesn't see an RPM drop, it should set a code..... I am not entirely sure just what criterion it uses to determine a failure though. It may have to fail three times in a row for the PCM to become annoyed enough....

what you could do, is wire an 'indicator lite' into the tcc circuit, so the lite comes on when tcc should lock up, and see if you do indeed get the RPM drop.

 

I don't get the RPM drop. IIRC, running 65-70 mph down the highway it's normally about 17-1800 RPM. I'll notice it isn't locked cuz it'll be 22-2300 RPM. If I hit the OD button RPMs will shoot up to 3-3200 RPM. That's why I believe it's the TC not locking.

EDIT: It also doesn't do it concistantly (sp?). Maybe that why there's no code.

 

Not that this will help much but I just took this showing the RPMs while it was acting up. And I'm sorry for the boat ride, the road isn't very smooth.

http://www.youtube.com/watch?v=Wvx-p...yer_detailpage

 

this is exactly what happened to mine only I waited too long and it left metal shavings everywhere causing the tranny to need a rebuild.

 

exactlywhat mine did for a couple weeks right before the torque converter self destructed... Its like it would go into a gear between 3rd and 4th....