Thanks for all the replies and suggestions. I now feel like I'm on a mission.

I pulled the valve body out today. Transmission is still in truck.

Tranny oil could use a change but still has a red appearance with no burnt smell. No metal chunks or slivers in pan, just small accumulation of "silt" on bottom of pan - gone with one wipe of the rag.

Everything looks clean, no junk in the passageways. Looking up through to other areas of the transmissions - the gears that I can see all look good - nothing missing - sharp distinct edges.

Looking at the "Powerflow Chart and Shift Solenoid Pattern". Looking at what reverse, 3rd and 4th(OD) have in common, is the "Direct Clutch"...

I'd like to rule out the "First and Second Gear Only" Condition outlined in the ATSG manual as it points to rule out electronic malfunction prior to pulling everything apart (aside from the 2-3 Shift valve - which I checked and didn't appear to be stuck - pulled the roll pin, slid it out-bounced it against spring).

I think the transmission electronics expect rpms on the input shaft before you can test, I tried with the system on, but engine offf and couldn't get voltages to change on solenoid's A and B.

Anybody have tips on testing the electronic inputs to the solenoids? I tested the solenoids by putting juice to them and they "click".

Thanks,

Paul