Hey Guys,
Obviously I have some what miscommunicated what the problem is.. I do know not to drive a part time 4wd vehicle locked in 4wd on dry pavement.. Here in northern MN, at least this year we've had alot of slippery roads. Sometimes there will be a couple miles of blown snow or/and ice then it might be good for a couple hundred yards or a mile, then slippery again..
In my estimate I've had approx 25 4wd units over the years so this isn't my first time around the park. I've never had anything that would pop out of gear like this.. Unless Isuzu's are exceptionally prone to this problem I'm sure she/we are doing nothing different than anyone else. I'm wondering if there is something possibly wrong with the actuator/solenoid that locks in the transfer case & maybe it's not putting it all the way in? I truly believe this is not a "driving style" problem. It seems odd that it would be this fussy as to the new front tires & used rear tires.. Hell, the older chevys & fords used to have slightly different ratios in the front & rear axle.
I guess I could spend the $300 for new rear tires to get a perfect match & give it a try. I'm thinking there is possibly a bent shifting fork or something in the transfer case so it will probably have to come out to be fixed.

Ps. To answer SteveÆs (bigswede) question yep, IÆm sure itÆs going into 4wd, I can hear it when it goes in as there is a slight whine that is common in part time 4wds. Sometimes it takes a while to go back into 2wd even with dropping the throttle or pushing in the clutch, stopping, backing up etc. Also when it does it kind of jerks a bit sometimes like the gears are hanging on the edge & finally slide over (or whatever they do on an isuzu) to get on the 2wd gear..
My wifes driving my Samuri right now so you can imagine how thats going! not good!
Anyway, I appreciate your inputs
Thanks Tony