Just adding a VERY IMPORTIANT DETAIL to Joe’s instructions…
While checking the fluid, make sure that your VX is in PARK, with the ENGINE RUNNING --- The fluid level that you’re looking to achieve only takes place when the transmission is circulating the ATF.
If you remove that upper plug with the engine off, it will allow too much fluid to drain out.
Oh yeah – one more thing:
Adding fluid to an Isuzu automatic can be a real pain in the butt. --- You’ll probably want to get a gallon jug kit of ATF, one that comes with a pump-action handle and a filler tube attachment.
HTH
"This trail is so bumpy, it's knocking my bra straps off!" - Miss Kathy