Grinding vibration that disapears in 4x4 high?

[markwillenbrock]

I'm worried about the front driveshaft and/or transfer box on my 98 Explorer. It's a UK spec 4.0 SOHC with auto 4x4.

The car gets very hard use in my job as a Saharan guide and fixer for tourists and TV.

The noise is road, not engine speed related, and is generally but not always there under load or on over run. It isn't guaranteed - it comes and goes.

It doesn't build or ebb away - it's there, or gone.

My car is right hand drive and my wife says she can feel it beneath her seat - which would be the drivers seat in most Explorers.

The noise only appears above 60mph, and doesn't vary in corners.

If I select 4x4 high manually, the noise disapears.

The vibration is bad enough to make my house keys (kept in the ashtray!) rattle...

I'm guessing a transfer case output bearing, but all suggestions welcome!

 

[gijoecam]

I'd start by removing the front driveshaft and see if the noise persists. It could be the CV joint on the driveshaft, or it may be something in the front axle... but if you suspect a front driveshaft, the easiest way to eliminate it is to simply remove it.

-Joe

 

[markwillenbrock]

Spot on, Gijoe.

We've take the front prop shaft off and the noise is gone, and there is play in the joint next to the transfer box.

I'm having the joint rebuilt, and we'll pop the shaft back on and see what happens.

 

[Mibeer]

The outcome????

I'm wondering the outcome of this... I'm having the same troubles with a 2000 Explorer... I'm getting a clicking noise while driving....Really bad with in reverse... Took the Fornt prop shaft out and the noises are gone... I did notice that the was some hard spots while rotataing the CV joint on the end of the shaft... Possibling making if bind up... most likey the cause...
Let us know your outcome..... Thanx

 

[markwillenbrock]

The rebuilt joint fixed the vibration - though at speed it's smoother without the shaft, though not by much.

Now the automatic transmission is playing up - the dreaded flashing OD light

I don't think there's any connection.