Trans lagging but "Haul" seems to fix it...

[_Spanish_]

hi everyone, so im pretty sure it's the filter since my transmission fluid level is good but unless i have the "Haul" option active the transmission laggs alot when changing gears and it revs at least an extra 1k rpms before shifting gear most times.

truck has about 230k km and so i think a new filter will fix this issue but wanted to double check with yall before going trough with it.

 

[latvius]

If you are going to change the filter change ALL the fluid this way
http://www.gmfullsize.com/forum/showthread.php?t=179148

 

[retiredsparky]

You could have the truck checked for transmission related codes. If a filter/fluid change doesn't fix it, you could have valve body problems or low pump pressure or...If there is a lot of contamination of fluid, that clutch material gets left in a lot of different places in the tranny and torque convertor. If you replace tranny, consider doing the convertor and cooler too. There is no practical way to clean out the convertor or the cooler completely.