Astro jumps when shifting after Startup

Guys, I have a weird issue with my dad's Astro.

It's a 93 V6 model Passenger Van with Automatic Transmission. Van will start normally but when switched to any gear (Reverse or any of the Drives) the transmission will jump, and particularly when going to Drive or Overdrive it will be a hard jump.

I got the Tranny Fluid changed, and the mechanic says that this is normal, but I'm still afraid the tranny will be damaged.

Is there anything I can do about it? We literally have to warm up the Van for 10 mins to minimize it. Anything else we can try?

Guys. your infinite knowledge and wisdom has truly left me speechless!

:disappoin

You guys were a big fuckin' help! God this forum sucks :(

it may be the motor mounts-does it only occur right when you put it into gear and if you floor the gas pedal?

Check mount at rear of tranny and U joints on driveshaft.

Did it jump before the oil change?
Was the filter changed?
Is it the right oil?
Maybe check the oil for dirt, or if it might be the wrong oil, change it again.
And thanks for swearing

when the vehicle is cold starting it will jump because it normally idles higher to get the engine up to temperature. Next time see if it happens when the vehicle is fully warmed up.