2003 XLT 4.0 4X4 with a low hum with mild vibration that starts about 53 mph. Doesn't get louder after about 60 and the vibration seems to remain mild throughout the speed range. Curious about ft end components ( bearings, cv/u joints, axle shfmafts etc.) New (well, rebuilt) tranny summer of 23, new flywheel, pressure plate,clutch, hydraulics. New tires 3 months ago, but I don't think it hummed like it is. Its a tough thing to describe. Sounds like a big truck is somewhere in traffic with me. It isn't exhaust. When I disengage the clutch at speed, the rpms drop but the vibe and hum remain until I get into the low 50's.
Thoughts?
Update:
ISSUE: Front drive shaft CV end imploded.
Replacement $148.00 from Detroit Axle.
Problem solved.

 

you have answered Both of my Q’s , I have developed the same with my 99 4wd and i have went thru my check list and just had realignment done and the mild rumble above 45mph is still there , sad part is the ol guy i buy truck from , never used it much , only 55k miles on it , to have to change whl bearing hub Now
2nd Q you answered for me was I wasnt shure what brand of WB Hub Assm. To get , So Detroit’s sound better the the other chyna crap steel/ bearing that pops up on 1st goog search
wonder Where the Moog’s are made.
Is their grease fittings on yours ? Be nice if their was , cuz ive seen a few apart and splines /shaft looked dry n rusty. Cheers n Happy Wheeln.