Well, … part time 4WD should be engaged often, … say, for 5-10 minutes, once a month at least. Otherwise, rust, dirt, etc. will make it hard or not operable, … and very expensive to fix.

F.S.

scotty,

i have a 1998 tacoma with the 3.4 automatic, 4wd with manually locking hubs. i've rarely used the 4wd, maybe 10 times in 5 years. 

i was recently testing the 4wd just to use it and i noticed when i tried to slide it into 4 low it didn't go in easily following the gear pattern and eventually did but with a noticeable rub or grinding feel on the shifter. 

i did this in neutral on flat ground. both 4 high and low seem to work fine i'm just wondering about the resistance it gave going into 4 low?