Hi There, my van a 2002 E-350 v8 EB is shifting rough between the 3-4 up and down.
I bought it with 140k miles and now I'm at 190k. I have no idea if it was serviced before I purchased it, I also have no idea about automatic transmissions since I've been driving stick my entire life. When I bought it shifted smooth.
When going uphill the van downshifts from 4th -> 2nd (skipping 3rd) and it feels fine. Then it shifts 2nd->3rd and it feels like a punch, you can hear it !. It remains in 3rd for a short amount of time before going back to 4th at super low revs, then it loops back to 2nd trying to hunt the right gear between 2nd-4th like if the 3rd slipped through. While this hasn't been an issue to get around, I noticed the punch is getting worst. I also feel the punch every time I accelerate in flat going from 3rd to 4th.
When engaging reverse, after shifting the stick it takes like 0.5 to a second to engage, if I give it gas at that time the same punch comes back.
I have no idea where to start first, should I try to send it for a full flush, change the oil? or straight up just rebuild it?
I know is a hard question to answer without physically looking at it. I'm seeking some advice on whats the best way to proceed since I've read horror stories about transmission flushes and I'd like to avoid a rebuild if possible.
If you also know a reputable transmission shop in WA Id to be very happy to get it there and have them take a look at it.