Happy New Year everyone.

Recently, my truck has been producing a loud whining noise in the front end. The noise is only present when the truck is in 4-Auto, 4-High, or 4-Low and only when going down the road. It's also intermittent.

Front pads and rotors are brand new and it has a brand new passenger side wheel bearing (initially thought that was the issue). Had it in the shop and the mechanic couldn't reproduce the sound.

Has anyone here experienced this issue and, if so, what was the culprit?

Thanks.

 

mismatched tires are an easy thing to rule out. make sure all tires are the same size, brand and within 4/32 treadwear.
have the fluid checked in he front diff and tcase.
bearings tend to growl. crown and pinion tend to whine.

 

Fluid levels are good per the mechanic. The tires are the same brand and size, but I'll have to take a look at the tread depth.

Thank you for the info!

 

If you are absolutely sure the noise is definitely coming from the front end, I’d put money on the front diff. When you select 4Auto, the front drive shaft spins as if in 4WD. 2WD is the only mode in which this doesn’t happen. That being said, it could be seals, bearings or even the gears. Unless you know about front differentials, I’d take it to a mech for a definite diagnosis. If it were the tires, it would occur in 2WD mode as well.

 

[QUOTE=Knuckles451;458284 If it were the tires, it would occur in 2WD mode as well.[/QUOTE]
nope...not referring to tire noise but rater noise caused in the tcase and diff due to rotational differences on a part time auto 4wd system; wreck havoc on the tcase and cause the front diff case to walk continuously.