4x4

[doug young]

Hey guys. Wondering if anybody can tell me why my 4wheel drive wants to engage while driving in 2wheel drive. I here a low rumble and feel a slight vibration, then i flip the dash switch to 4x4 and the rumble goes away.....hmmm.

99' f250 160,236

Thanks, doug

 

[bigrigr]

Do you have the hubs locked in? Could be something in the transfer case that is turning with the hubs in and the transfer case in 2wd?

 

[Tail_Gunner]

Hey guys. Wondering if anybody can tell me why my 4wheel drive wants to engage while driving in 2wheel drive. I here a low rumble and feel a slight vibration, then i flip the dash switch to 4x4 and the rumble goes away.....hmmm.

99' f250 160,236

Thanks, doug

The virbration might be a bad axle shaft roller bearing inside the bearing hub on that side.

There are two bearings, one is the main load supporting bearing. The smaller roller bearing supports the end of the axle shaft when the truck is in 2wd. In 2wd, the front driveline is unlocked and should not be rotating when driving. But obviously the wheel is rotating. So the lockout hub is spinning with the wheel and the front axleshaft is not. That little roller bearing is what supports the stationary axleshaft while the hub rotates around it. A little known preventative maintenance item is that bearing needs to be greased every once in a while. If that little roller bearing goes bad, you will get some noise and maybe vibration.

If you lock the front hub (putting the truck in 4wd) the axle shaft begins rotating along with the wheel. The roller bearing stops turning and the noise stops.

 

[CKyle494]

I had a plug that had came half undone at the transfer case causing it to "grind". You might want to check all connections there. It is zip tied up now and not a problem for 3 years now.

 

[hinesenhoffer]

Hey guys. Wondering if anybody can tell me why my 4wheel drive wants to engage while driving in 2wheel drive. I here a low rumble and feel a slight vibration, then i flip the dash switch to 4x4 and the rumble goes away.....hmmm.

99' f250 160,236

Thanks, doug

Hey doug,
did you ever find out what was causing your truck to do that,cause mine is doing the very same thing.
Thanks ,Gary