When using 4wd in the winter on my ifs truck I get a loud vibration from the front drivers side. I usually just unlock that side and run just 3 wheel drive to avoid the noise when it's snowy.

Doesnt happen when unlocked. The cv boots are in great shape. It has to be a bad cv joint though doesn't it?

In 2wd or 4wd "free" are both the inner and outer wheel bearing in use or just outer?

As soon as weather is warm I'll tear into it, but just wondering if anybody had experience or thoughts on this. Thanks guys.

 

Unless you have some sort of locker or LSD in the front differential, you don't have any front drive at all with one front hub unlocked.
Might be a locking hub problem (not locking correctly), or CV issue: might also be an internal differential issue where no vibration occurs when there is no load, and there would be no load on an open differential with one hub unlocked.
You're gonna need to jack the front end off the ground and do some more troubleshooting in order to find out what is really going on.

Both wheel bearings are always in use, hub locked or unlocked.

 

So with open dif and only one wheel locked and in 4wd you're saying the front pass side wheel isnt pulling? Definitely was last winter. I have no idea if its got an lsd in it.

 

That is correct.
With open diff, if one hub is not locked, no drive will be transmitted to the locked side.

 

Interesting... I obviously didn't even consider a locking hub problem. That may be it. But I may have an lsd up there then cuz one tire was still pullin me along.