Transmission Question

[Sherlock]

Hello,

 

I have an 02 Yukon XL 2500 4WD 8.1L with heavy duty tow package. 35K miles.

I have never towed it or abused the truck. I park on a steep driveway nose up, and recently I have noticed about once a week when cold starting.....the transmission takes 6-7 seconds to achieve power. If I step on the gas in gear the engine revs and then eventually I get toque. This only happens maybe 1 out of 6-7 cold starts. I also feel I am getting a little less power in first gear from stop lights etc. More revs than needed before perhaps. My fuel economy has declined from 10-7 mpg in the city. I have never raced or abused the vehicle. I recently had it serviced and they were surprised the tranny fluid was very dark (it should not have been).....and they changed it and the problem still occurs. Any ideas what might be going on?

 

Thanks!

[Frozen001]

Could they have underfilled the transmission fluid??? Check the fluid level when the transmission is at operating temperature... the fluid has to be warmed up on these trucks because the level moves more than you would expect... I know because trucks transmission was underfilled (long story behind it) and it would slip....

[Sherlock]

Thanks but I took it in for service because I was having the problem for a while. When they serviced the tranny (at 35K well before the recommended 50K service)....the fluid was almost black. Not normal. My problem is still the same after the service and the level reads full.

 

Thanks for any ideas.