When only in 4WD it sounds like a bad wheel bearing. I'm not going to say a grinding noise but it sounds like a bad wheel bearing.When only in 2WD no problem. Any thoughts?Thanks

 

Is it making a ticking noise at all? Does it change with vehicle speed? Does it change if its in 4 low vs 4 high? It's probably the Pinion bearing on the front differential.

#9 and #4.

 

I've only driven the truck in 4WD high during the winter days when there is snow on the road. Noticed one day when I put in 4WD high that I noticed the noise, never did it before that day. No ticking noise , it's does changes in vehicle speed, not noticeable at higher speeds just low speed.

 

Check fluid level in the t-case, and front axle.

 

Yes I am planning on changing the fluid in the T-case and will update when done. By the way can I test the 4WD on pavement or asphalt after I change the T-case fluid?

 

NO! Do NOT engage 4x4 on a high traction surface, that tends to break things.

 

Problem was the cv joint on the front drive shaft.Good to go again. Thanks everyone for all your input