I am getting a growling noise from the frontend. It almost sounds like driving on the rumble strips on the highway, but not as loud. When you switch from 2WD to 4WD the noise goes away. Would this be the front diff., axle hub bearings or the transfer case? Any ideas?

 

it could be due to a vac leak in the 4x4 system, this has happened to me as well as many other people I know. The 4x4 system works opposite to what I thought so if you have a vac leak your hub is engaging every so often and grinding. When you put it in 4x4 it releases all the pressure and the hub locks in so no grinding. I am on my 3rd hub. Look at the solinoide and then the hubs.

 

X2

 

I have the same issue (grinding type noise), but I don't think it's the 4X4 vacum thing, because the shop that put my lift on changed it, or something like that. However, it's not the wheel bearings either, because we changed the one where the noise was coming from, and it still makes that noise. I take it the solinoide should be my next guess...

 

I thought the same thing but theses hubs and bearings are hit and miss. If you had one bad one at any time there is a chance it ruined your other one it just took a while to go. I am having my left side one replaced this week for the second time because the shop put in a used one last time and it failed and destroyed my right side and now it's finally grinding. this will be number 3 in 2 years because we didn't do both at the same time. The solinoide goes all the time to bu none of this usually just goes it will be intermidat and one thing effects them all.

 

well i got my truck back today the entire 4x4 system has been replaced:

-5th damaged hub
-vac solenoid
-all vac lines

There is still a periodic noise coming from the front end, I am still grinding hubs and don't know why, so ignore all my previouse posts, I don't know ******

If anyone knows whats up or figures this out, let me know!!!