Another Front End Grind

[jay_c]

I have a 2002 4.0 4x4 XLT. The problem, well this problem, starts only after the vehicle warms up, or has been driven for more than maybe 20 miles and happens during turns. It is a grinding sound from the front end and seems to come from maybe both sides. Vague I guess, but I was maybe hoping someone would have an answer based on the "post warm up + turning" variables that I have mentioned. I know one hub has been changed back in 2007. Just maybe hoping someone else has a "that is exactly what I had. It's this" comment.

 

[imp]

Unfortunately, it is wishful thinking to hope that some certain "sound of failure" will be exactly as described for more than just the one vehicle. If the same part failed on nearly all of them, it would help.

So, what you experience might be temperature-related. Wheel bearings, generally, when failing, will warn us with their grumbling sound for quite awhile, but it's there cold or hot. I'd rule out hub bearings, then. But I could be all wrong, and that's what makes all this so much fun!!

I would lean more toward thinking of differential side bearings. They produce masked sounds of distress when the oil is cold and thick- (we used to put heavy gear oil in engines to mask bearing knocks!). Still in the differential, pinion bearings howl like hell, since they are under high preload conditions, and oil temp. matters little to them.

Just my $0.02. imp

 

[jay_c]

Ok so:
Dead wheel bearings - Grind whether hot or cold
Differential Side bearings - Don't make a noise when oil is cold, but do when the oil warms up
Differential pinion bearings - would make themselves know if they were cold, or warm

Am I with you so far?

I am trying to get a sense of where I am heading and possibilities of what to look for before I go diving in there.