I checked out the rear end and it seams to be ok, so I dropped the trans. pan & filter. Metel filings were present in the pan and "goo" at the bottom. The filter weighed alot. So, I cleaned up the pan,put in a new filter & fluid and that didn't fix it. ? transfer case bearing? Any ideas would be greatly appreciated as am working on it outside in zero temps right now.

you need a new transmission or have that one rebuilt.

well its to late to do much more than replacing the trans once is slips most of time its done and really it could be either with 4x4 but most likely trans shot

If you had Metal filing in your pan and if the goo is green that is not a good sign, you will probably need to rebuild your transmission

It sounds like your low-reverse clutch packs are shot. That is usually caused by a seal on the piston either torn or cut. That is common for a vehicle that age. Transmission would need to be rebuilt to repair this condition.