hard 3-1 downshift, and 5R VB on a 4R

[SensRanger]

Okay I wonder if anyone can offer some suggestions as to WHAT is wrong with my truck. After a rebuild and a couple problems things seemed ok until i noticed a hard 3-1 downshift clunk/clank from the trans. when coming to a stop. It was not the slip yoke or u-joints, i had those checked. So I brought it back to the trans place and they had it for a week tweaking my 4R55E VB but they admitted they could not get it right. So he said they'd replace the VB. Got the truck back, he said they put the 'updated' VB on it, I asked, the one for the 5R55E? Yes he said. So if you put a 5R55E VB on a 4R55e, does that essentially make it a 5R55e or do I have some kind of combo now.?
And.....the clunk is not completely gone! It definitely seems less noticeable and does not activate the ABS (so far) like it sometimes did before...but it CAN occur! (before the VB swap it happened EVERY time you stopped, at night it sounded like someone banged the underside of my truck with a metal hammer). Does anyone know what causes this hard downshift??? And, do you think my 5r/4r hybrid is all good?? Thanks!!

 

[BrooklynBay]

The 5R VB is OK to use on the 4R. The computer is compatible with it, but will not add an extra 5th gear. Did they check the pressure of the transmission with a 0-300 PSI gauge? Maybe the pressure is low, then it suddenly jumps up to normal, and engages gears. Does the new VB have new solenoids, like the EPC, TCC, and shift solenoids? Hopefully the shop used the new bonded gaskets with the separator plate, used an In-Lb. torque wrench to set the torque of the VB bolts, and flushed out the front cooler.