Noisy when in 4x4, in decel or accell, but not in coast

[Mark_ZZ3]

I have a 1991 Explorer XLT. When in 4x4 HI, at a steady speed, perhaps light throttle, all is good.

On decel, you can hear a growl or whirr sound from the front end.

On Accell you can hear a similar sounds.

I assume this is something either on the hubs or the front gears.

It is common that the front hubs can be heard like this? Or is it a sign they are wearing out? If so, what part is exactly wearing out?

It almost sounds like a ring and pinion noise, like you have the backlash too loose and you get a growl.


I am going to change the front diff fluid becuase it is past due and make sure there is nothing in the fluid.

Anything I can visually check on the hubs to see if they are worn out?

Mark.

 

[jimbo74]

sounds like it could be normal... the rear probably makes noise too, but you are further away from it......

 

[Mark_ZZ3]

I can't say that it has ever been quiet in 4x4, but this year with all the snow, I seem to notice it more often. If you drive with the radio off, you can certainly hear the HUMMMM.

I guess I need to drive in another 1991 4X4 and see if it hums the same.

I just don't want the darn thing to dynomite on me when driving.

I need to do the radius arm bushings, so I guess I will have a closer look when I do all that. I hope it can wait until spring.

Mark.

 

[Doug]

my t-case makes the same noise... i have to check the fluid level you should do the same.

 

[nestorb]

Check your U-joints--I had the exact same problem with my 91 Sport only it wasn't happening consistently--turned out the left U-joint was almost frozen--haven't heard that whirring sound since--Barry