Front Drivetrain Noise - ideas?

[vincewarde]

1993 Explorer 4x4 4.0 V6 AT - 212k miles

Has a low to medium pitched growl/wine noise when front drive line is turning - including when hubs are locked and 4WD is off. Unlocking hubs stops noise.

Originally Auto hubs, converted to manual 18 months ago.

Front End work 12 months ago, including wheel bearings, brakes and front axle shaft U-joints.

Rest of front drive line is probably original.

Oil level in front diff is OK.

I know I need to check hubs and the U-joints on the front drive shaft - any other ideas?

Thanks!

 

[RangerX]

Bearings.

 

[vincewarde]

Bearings.

Thanks - I was thinking about that. Any idea which bearings? Where should I focus my search?

 

[Roadrunner777]

I have seen where a slightly loose wheel bearing can make different noise if the hub is engaged, so I'd say that the wheel bearing is a cantidate. So is the spindle bearing. Make sure the splined washer and C clip are on the end of the axle (the end that fits in the hub.) If the axle is floating in the spindle, that can make this noise too.

 

[RangerX]

Thanks - I was thinking about that. Any idea which bearings? Where should I focus my search?

The wheel bearings, on whichever side the noise is coming from. Or is it from both sides?
I know you replaced them (or had them replaced) a year ago, but if they weren't tightened correctly, they could have gone bad...

 

[vincewarde]

The wheel bearings, on whichever side the noise is coming from. Or is it from both sides?
I know you replaced them (or had them replaced) a year ago, but if they weren't tightened correctly, they could have gone bad...

Yeah, I did the work myself (with muscle help from the son in law). We did the ball joints, brakes and bearings. I'll try locking one side then the other to see if we can isolate to one side - then tear it apart.

Thanks!

 

[vincewarde]

Update - Still searching

OK, we have torn down that whole side (the side that was making noise) and the only problem we have found is a chunk broken out of one roller in one of the wheel bearings. I took the spindle to a driveline shop to have the bearing pressed out and he said it looked good to him. I am going to clean it out, inspect it and repack.

Could that one flawed bearing be responsible for the whole issue? Any other suggestions?

Thanks!

 

[Tony H]

Sure.

 

[cloaked_chaos]

Since you already have it out, just replace the bearing.

 

[vincewarde]

Problem Located and Solved

OK, we figured out the problem. The seal on the back side of the spindle - the one that protects spindle bearing from contamination - was broken in half. This permitted dirt to reach the bearing. When I locked the hubs, instant horrible noise.

Fortunately, I caught it before the spindle bearing was damaged. I cleaned it out, repacked it and installed a new seal. We also replaced the questionable wheel bearing.

The results: No more noise. 4WD works great.

Thanks for the help!