i have an lly with the 5speed allison and about 10k ago i had a local shop do a suncoast iv with a 1056. it always shifted hard into fifth but now had recently started getting worse.... It will kinda give you whiplash when it goes into 5th when the accelerator pedal is barely pressed(just slowly accelerating), but when im at WOT going through the gears it seems to be a lot smoother. im wondering if i should change the fluid, filters, or have my tcm tuned??? The guy did tell me that he put a heavier spring for the 5th gear shift, should i have that changed? any help would be greatly appreciated. thanks
