When I first start the van and put in drive it takes several minutes for the transmission to finally I guess build up enough pressure to finally get moving. If I put the van in neutral and rev the engine and then put in drive it seems to greatly help a d trans has decent acceleration. Does engage all gears and does not change gears rough or no hard shifting. I'm assuming the pressure control selenoid but not for sure. Just recently it seems I am hearing a routing noise that changes pitch from low sound and goes higher in pitch as the vehicle increases in speed. Noise is present that I can hear from like 10 mph very low pitch to high pitch at 65 mph. Pitch present whether in nutreal at speeds or in drive. Already jacked vehicle up and did not find any issues with cupping of tire or wheel bearing. Also put van in drive on Jack's up to 40 mph on speedometer but can not seem to identify a specific section of the transmission maki m the noise. So assuming something internal but not sure what parts. Does anyone have any ideas or suggestions?

 

check fluid is topped up and not burnt. That's about all you can do.

An incorrect filter can cause starvation, but you would have noticed that before.

A specialist can use a high end scan tool to run a diagnostic system check on the transmission. To me it sounds like excess slippage from a worn out TCC. The noise could be the pump. Either way it's an internal issue and the solution is a tranny swap. 232k is a lot of miles.