Driving in 4WD mode only once a year

[Thrasher_S]

My last rig was a Nissan Xterra. I bought it used from a woman who used it as a grocery getter. Only scratch on it was from her rings digging into the paint when pulling the rear hatch shut. I don't believe it had ever been in 4hi and certainly not 4lo.

The first time I tried to engage 4hi, it took a looooooong time, then clicked in. After that it was almost immediate. 4lo was fine.

However, the first time I had 4hi engaged for a significant amount of time I developed a nasty leak in the transfer case from the front drive shaft seal. Coincidence? Defect? Old dried out seal from not getting lubricated monthly? No way to tell.

 

[downshift]

I had an '03 which was full time AWD, so no need to worry about the 10 miles/month in 4WD thing, but I never locked the center differential. Never had a need... The center differential started leaking, and I traced the leak to where the locking actuator entered the case. I think lack of activating this caused the seal to dry up and start to leak. No proof of course, but I am now of the opinion that going into and out of 4WD (and locking the rear diff if you have one) to operate the actuator(s) is as important as driving 10 miles.

(Some models have an actuator on the diff itself, others do not, but they all have an actuator on the front axle.)