Hum... or vibration... starts at 60MPH

[hwoolfolk]

I have found this forum.. hopefully the people here know everythihng! I certainly dont and would appreciate your help.

2004 Explorer.. V8... When I get the truck up to 60MPH a hum or vibration starts. It appears to come from the front drivers side. I have chased this problem for months (at least 4) and have done the following... in this order:

- New wheel bearings.. 3 total... not the left front. ( I took it out this past weekend and it turned very smoothly.... could it still be bad?) I dont think it is that last bearing because if it was bad I would hear it all the time.

- Dew drive sfaft (short one... $300 one)

- New tires

I was thinking maybe the half shaft but someone in another forum suggested changing the T Case fluid. Truck has 118K miles so I am gonna do it anyway.

No vibration in the steering wheel or really any place. Just this annoying hum

You know.. I just had a stupid thought... it would piss me off if this was it ..but.. maybe it is not mechanical at all.. .maybe it is a body molding or something flapping in the air underneath?

Ok... assuming it is not that.. any thoughts? I need to drive from Boston to Burlington VT on Sunday.. 3.5 hours. dont want to do it at 60mph!

Thanks

H

 

[PopRichie77]

Just a thought, the insides may be loose in one of the cats or the shield. My wife's Mercury had a noise like you describe, drove me crazy, it turned out to be the shield, double wall, on one of the cats, fixed it by putting several sheet metal screws in the 2 layers of shield, not into the cat metal.

 

[hwoolfolk]

just changed the Tcase fluid. Taking my son to a friends. Will check for things like that when I get home.

There is an insulation shield inbetween the T-case and the chassis. It is loose. Im gonna secure it just in case for Sh*ts and giggles.

Its amazing though.. its a faithful hum at 60 mph.

Any other thoughts?