I have an 02 Denali 6L AWD with 4L65E with shift kit + custom tune. I lost second on a 1-2 shift today. 4th and 2nd are not working. I think this is the power band but I am not a tranny guy.
I need some advise on how I should proceed to get the best fix for the price. I plan to upgrade to a higher stall converter as well. Any thoughts on the converter? I may add a supercharger later but for now it just has an aggressive 93 octane tune with cold air on the motor.
Thanks,
Scott

 

well, judging by your future mods I would recomend a FLT65e from Finish Line Transmissions
They are the BEST GM tranny builders IMO

 

Whatever you decide to do for the rebuilt or just replacing the transmission, DO NOT set up the shifts to be too firm. Jolting shifts kill these transmissions. The 4L60/65/70e have to be a compromise between making the clutch materials last longer and hold up under power and making the hard parts last longer and hold up under power. The hard parts are weak so you have to choose to let the clutch materials expend themselves as intended. Make shifts slightly more firm than stock but not harsh.

 

do you still have reverse????

 

I still have reverse... I have been looking at FLT level 3.

 

a level 3 is a bad call in something that heavy IMO... you should be looking at a 4 AT LEAST.... and thats if you drive like a granny... IMO, do a level 5 or go to an 80E in that heavy pig.

 

If you have an SE light it could be the silenoid

 

I'd bet on the 2-4 band. Smae thing happened to me on a WOT run. That was a fun ride when it went to shift to 2nd and the band broke so it went back to 1st then to 3rd.

I PM'd you some info. I didn't know about your future plans. If you're going to SC the Denali you need at a minimum an FLT level 5. Going to an 80E would be the best route. I didnt becuase I dont want that gearing but it is a lot stronger.
My level 5 is holding up well but, I dont beat on it all the time either.
Also, if your luck is anything like your brothers, you should just sell the Denali.

 

ditto..i broke 3 of em and now with the flt level5 it's holding up very well....

 

Yeah, it runs in the family for sure. I tuned his truck, that's why it broke.