I have an 04 6.0 that recently had a solenoid pack replaced in the tranny by my Ford dealer. It was fine until the cold weather set in. If I let the truck warm up for a while it goes into gear fine. But more recently in the extreme cold we have had (below zero temps) it is more of a problem. Trans fluid level looks good and the service order lists XT-6-QSP fluid, so I am assuming they used the Mercon SP. I am going to take it in to have them check the codes because the tow/haul light will flash if its not warm enough and has trouble moving the truck. Any thoughts?

 

It was very common for the first generation Torqshift's fluid temp sensor to fail or give false readings. IDK, just spilling the wheel of diag here. Bring it back to the dealer as if it is solenoid related both diag and replacement will be covered under warranty.

 

That means codes have been stored. Without the codes nobody knows what's wrong. The codes will direct the diagnostics towards the problem.

 

LV is thinner than SP. If the cold is thickening the SP to the point of problems, might be worth looking into runnning LV.

 

Took it in to my Ford dealer a couple of months ago and they replaced the valve body and everything was ok for a while. Now I'm getting erratic and hard shifting. It even caused the engine to stall as soon as I dropped it into fwd or reverse on one occassion. I disconnected the battery to get it to re-learn the shifting points and it was ok for a few miles but the shifting got progressively worse again. Tow haul light came on again. I got an OBDC reader and it is saying unexpected gear disengagement. Could the tranny be ok and the computer is just screwing up the shifting?

 

Not likely, but not impossible. How is the fluid level?

 

Sounds like the shop is not quite sure what the issue is. One thing with these newer transmissions is that they have wiring underneath. Putting on parts like a new solenoid does not do much good if the wiring harness or connector is damaged. It can happen and can be overlooked.

 

Fluid level is good. That was my first thought too.