Jeep 1997 XJ Front Differential and Transfer Case...
 

Ok, I have a Jeep 1997 XJ and when I go into 4 wheel drive I can hear
a moderate whirring sound from the front differential or transfer case
(?) particularly when I hit around 40 mph or more... Anyone else find
this so... all fluids are good and full...

If so, how fast is it ok to go in 4 wheel drive...?

Thanks!

PL