There is no problem with driving in 4wd at highway speeds. Your truck will do just fine. The only problem you will have with driving in 4wd on the pavement is when you go to make tight turns, in which case you will bind up the transfer case and then possibly do damage. You can drive in a straight line at 100mph in 4wd with no problems.


Sounds like it was never in 4wd though. You would definetly notice it was engaged on the pavement making turns.

88 4R, 350 V8, R150 5 speed Sold <...uot; />
97 4R, stock, daily driver
98 Sienna, kid and dog hauler, wife's ride