[Adger Smith]

It is correct the band adjust has nothing to do with rolling forward. It is in full apply when going forward. What are you going to do, loosen(adjust) it so it slips? ;~) The problem is the low band is applied & it takes toooo long for the rev clutch pack to tighten up & lock the tranny in low & rev. Pull the pan and check the clearance in the rev clutch pack. That can be done by inserting feeler gauges through the small square hole below the Rev clutch pack. (have to remove VB to see) Let us know how many thousands it takes to wedge the pack tightly. I suspect you have a tranny that may still have too small a supply hole. (Had known builder do that to me way back before I started doing my own) The stock feed hole is about .060. Should go to at least 5/16 or 3/8 for good fluid flow. That is if your VB is the type using single feed. Some have a feed & dump, dual...More holes to drill... Or you could have the wavy steel still in the clutch pack or you could have low pressure or you could have too much clutch pack clearance. It isn't going to fix it's self. You need to do some checking before just pulling it out. Did you check the pressure on the rev pack when you hit the T brake? You can also
air check the rev clutch pack, just like you can air check the low band when the VB is out. (not through the same fluid port, though. Did you do the tranny yourself or is it a well used unit from someone else? Hope this helps.