Adding fluid to 99 Isuzu Rodeo automatic transmission

After reviewing several previously submitted Q&As, I have chosen to add automatic transmission lubricant to my transmission as the initial step in resolving my problem. The owners manual indicates two filler plugs. One, which is threaded, near the rear where the front wheel drive line enters. As for the second, I only find a plug secured by a snap ring toward the front, both on the right side. Is this a filler port? If so are there any tricks to getting the snap ring removed. I have a snap ring tool that I have struggled getting a decent angle or leverage. May transmission fluid be added at the rear port or is it a differential gear box? Thanks

You have two identical hex head plugs, both facing downward on the main transmission pan. The plug stamped/recessed up high into the rear corner of the pan is the fill port, the lower, more visible plug is the drain. You need to check ATF level with the truck idling, warm, on a level surface & while in neutral. You have to pump ATF up into the fill port with a handpump or equivelant. LOTS & LOTS of posts on these boards in regards to ATF/ level checking/servicing of the 4L30E.
G/luck
Joel

Anybody know why Isuzu (or GM -- it is a GM transmission, right?) chose not to put a filler tube/dipstick on this baby? Surely it couldn't have been that expensive...

Anybody know if there is some sort of retrofit kit available? It someone came up with an easier way to monitor this transmission's fluid level, they could make a buck or two...

JWS
'99 LSE 4WD

I can only think of two reasons,
1) to make it a dealer service only item & generate $$$ for dealerships .
2) to appeal to the 'sealed for life' -or- 'maintenance free' crowd, which totally does not fit in a 4x4 truck!!!

Joel