2006 Chevy 2500 HD Issues
 

I just got a 06 2500 HD with the 6.0L and a 4L80e. Today I took it to Walterboro and back where it started getting up to 230 degrees while toeing a cargo trailer and about 1000 lbs.

Also, it feels like it is starting to slip because we I start moving from a stop there is a slight hesitation and feels weird while the torque converter unlocks at cruising speed.

The fluid level was good, no leaks and the truck drove well on the test drive.

Any ideas or issues that are known?

I got a great deal so if it needs a rebuild, that's not a major deal to me.

2006 6.0L/4L80e/120,000 miles

Those clusters are notorious for going out unsure about reading wrong. Change thermostat and see how it does.

Sorry Tyler, trans temp gauge was reading that!

80e TCs do not stay locked up for some reason.

While you were towing on your Walterboro trip, did the converter stay in lockup? If it wasn't spending much time in lockup, trans temps would climb above normal.

It kept bumping in and out of lockup.

Do you think you could look at it this week?

Engine misfire will make it unlock also

No codes are being thrown. I guess it just needs a little TLC!

One of the first things to doublecheck is to see if the PCM is actually giving the command to unlock the converter. If the PCM isn't calling for the unlock, this might help if the converter clutch itself hasn't overheated and no other driveability concerns are contributing to it:

http://www.sonnax.com/system/announcement/34994-01K.pdf

Dropped it off to Rob, MonteC.

I know he will take care of it