LBZ: Torque converter locked

[kenny]

I have a new problem with my trans I'm trying to figure out, and I'm hoping someone has a better idea of what it could be. It is the stock trans. The truck is fine when its cold and shifts normal. When the engine temp reaches 180, the truck locks up the torque converter. It pushes through while braking and starts off in 2nd gear from a stop. The tranny makes a hissing sound at a stop with the truck in drive. Let me know if you need more explanation on this. Thanks in advance for all the help guys.:hug:

 

[paint94979]

is the transmission tuned?

 

[Mike]

Mine did this when the stator broke. I just don't remember being temperature related. Hope yours is an easier cause. Good luck.

 

[kenny]

pretty sure the trans isn't tuned? These symptoms started shortly after the elevated idle crap kicked in while we had the cold weather.

 

[IOWA LLY]

Sounds like a draggy converter clutch maybe.

 

[Mike L.]

I'll bet the converter is trashed.

 

[LBZ]

pretty sure the trans isn't tuned? These symptoms started shortly after the elevated idle crap kicked in while we had the cold weather.

The first stock TCM tunes that came in the 6-speeds were found to cause the converter to overheat and fail due to the extended warm up period during high idle. Later updates to the TCM programming fixed this sometime in late 2007/early 2008.

I would bet yours still has the old programming in it and it subsequentally cooked your converter when it idled up on you.

 

[dubious]

I live in Canada and have gone through this twice now, once with the first update
My truck did not exhibit those symptoms, it cooked the converter and then 5th gear clutches when i was driving it, and the dealer attributed it to cold high idle overheat.

The temps should be around -40 for the trans to overheat when high idle.
Its got to be cold enough for the fluid to gel and block circulation to the cooler.

 

[kenny]

Converter was trashed and clutches were fried... All better now...