noise when in 2 wheel drive

[ccoker]

87 4 Runner is making a noise when in 2 wheel drive at 20-30 MPH occasionally on the right side, kind of a "WHIRRR" sound that is pretty loud

The front hubs stay locked and when I put the 4 wheel drive selector to High the noise instantly stops...

It's on a deer lease and does not get driven on the road or over 30 ever...

90% of the time the 4 wheel drive is in high and when coming back to camp sometimes I take it out of 4 wheel drive

Thoughts on what it could be?

More importantly, if I leave it in 4 wheel drive high, does it hurt anything?

Thanks...

 

[Bad_Vision]

if you drive on cement or ashphalt 4wd will bind a little and long term use is inadvisable, if your on dirt or snow it should hurt it as much and be fine.
as far as the whirr sound its normal might be a good idea to rebuild the hubs and put new greese in it!
like all vehicles, what is it worth to you to keep it in good condition.
If you dont want it to break then fix it, if you just want to drive it till it dies then dont fix it.