Are you supposed to turn the tow/haul button off when you make a pass?
When I run, I put the truck in third, but don't turn off the tow/haul button. At approx. 87 to 90 MPH it sounds like it shifts gears. I had my tuner check to see if he had the stall locking at that speed and the truck is not locking the verter at all in WOT. Any ideas???

 

I dont use the tow/haul (performance) button at all. I also run in D.

 

run it in 3rd with no tow haul.
it sounds like your converter was locking up.

 

Depends on the tuning, the tow haul only changes the shift points and converter lock up points....

 

No tow/haul button and I also just put it in drive and hammer it. My truck knows better when to shift than I do.

 

yeah. you need to find out from your tuner if he tuned the Performance shift tables which the tow haul would put you in.

 

just have him tune it for D at WOT so you dont worry about the tow/haul button.

 

thanks for info fellers. I'll check with my tuner. If the verter has a problem, i'll get it reworked to 3600

 

General question for you chevy fellas... Typically how much ET and MPH increarse is gained from locking the converter in 3rd gear? My converter doesn't lock up at all in the 1/4 and I'm just curious how much I could expect to gain from that. I'd imagine at least 2mph, and probaly not a whole lot of difference in ET??

 

on my Fbod thats how it was. 2-3 mph and not measurable ET.