My old tranny went out and I replaced it with used one from a reputable JDM engine dealer here in Atl. It upshifts fine even cold with no issues at all. But when it downshifts while slowing down or braking, it makes a sort of jolt feel and noise. torque converter? any adjustment?

 

check ur motor mounts

 

did that. tight and not too worn.

 

i hve a new trans it does that and so did my old one i was told its not a big deal though

 

jerks on downshift are rarely mounts as there usually no power applied. is it slipping at all on the upshifts? if not, change your fluid using the 3x drain fill drive 5 miles repeat method.