to start this is a 2005 yukon with a forged 5.7 with a sts ls6 heads and cam and 918 springs and 3.42 gears and 24" wheels tci 3000 stall . Truck makes about 500 rwhp and 550 rwtq transmission lasted about 300 miles after dyno time!!!. Got truck back today with built transmission and truck drove fine back to shop about 50 miles. When i get back i pulled it out on the street and stalled it up good and lunched it . it felt like it had a lot less power and not really fast at all when I was slowy down i saw that the trans temp was up to 250/275 range and the truck was way up around 260/270. I let the truck cool down and went and drove it some more as long as you don't really stall it up it seems to be fine and runs strong. If you stall it up it will overheat everytime and it takes along time for the temps to come back down. Anybody with any ideas. is this a bad transmission or a bad converter or is that just the way they are in 90 degree heat thanks

 

If it is the trans the PCM wont log any code until a few miles are put on it. (that is what I was told) Kinda sounds like a converter slip with the trans heat, but with the eng too?? Does it have e-fans?

 

Chceck your fluid levels. I've had the same situation in the past after getting my truck back after a transmission install. High temps, loose converter feel, sluggish.... turned out to be 3+ quarts low on fluid.

 

yes it does have elestic fans and the fluids look to be good

 

You sure the fans are working properly? (sp)

 

with that much power you coudda gutted your stock verter or screwed up the tranny and verter...

 

electric fans are factory and i am pretty sure are working correctly

the factory trans had the tci converter in it for about 350 miles we used the same converter in the new transmission