Newbie to 1st gen, need transmission advice

[DBoggs]

My son just joined the Air Force. While he is away at boot camp I am trying to help him take care of some issues he has been having with his truck.

It is a 1993 W350, auto, 4x4 dually, 3.54 gears.

The transmission appears to be slipping in all forward gears. I initially thought it wasn't downshifting to first gear, but after driving it today for a greater distance and manually shifting it from a stop, I realized it is shifting through all the gears. Including overdrive. It will shudder from a dead stop and the engine revs pretty high in order to get up speed. There is no tachometer so I can't tell the rpm's.

Reverse appears to be normal. It doesn't feel like it slips at all.

The fluid is full.

I've been reading the different posts and can't find any that match exactly these sysmptoms.

I have not pulled and cleaned the TPS, though it doesn't sound as if it would help. Overdrive is working.

I have not had the transmission serviced or adjusted either, though just as soon as I can I intend to, if anyone thinks it might help. Or is replacing the trans a better idea?

Money will be a consideration since my boy is just starting his military career and won't have much for a while. And I'm not wealthy either. (just lost my business and my Dodge truck)

Any help is appreciated and I will attempt to do as much of this as I can, time, money, and knowledge permitting.

Thanks,

Duane