Superduty drivetrain noise

[homemade]

I thought I would throw this out to see if anyone has experienced anything similar to give me more direction.

Problem :

2004 F350 4x4 crew cab, short bed, SRW, ~120,000miles

Few weeks ago developed what I would describe as a pretty loud howling sound at any speed above 10mph, no vibration, loudest 35-55mph, drowned out by road nose above 65 but still there. Becomes slightly higher pitch at higher speed but doesn't fluctuate with engine speed, just overall vehicle speed. No change in or out of 4x4. I thought it was coming from the front end so I replaced the front wheel bearing assembly with Timken units, replaced rotors and pads (because of a bad brake pulse that had only temporarily improved with having rotors turned few yrs ago) - no change. Pulled the auto hubs to see if that was cause - no change. I Googled it and found some forums that mentioned carrier bearing or pinion bearing causing similar sound. So maybe it isn’t coming from the front. When the truck was new it had a rear end clunk and the dealer fiddled with the pinion bearing so I wonder if that is going. Driveshaft is tight, the carrier bearing looks OK, no leaking from the differential. Shifts fine, trans fluid clean and without any odors. Tires without any funny wear pattern and same tires on truck for past 40,000 miles (Michelin).

The front bearing assembly is an easy driveway job for anyone who needs to do it, I think the old hubs may have leaked lubricant from the sealed bearings because there was quite a bit of a thin light blue lubricant in the knuckle joints when I pulled the bearing assemblies, the inner needle bearings were in fine shape and didn’t lack lube. But in any case new bearing assemblies didn’t help.

Any experience with a sound like this?

 

[nely]

Does the noise go away during coasting, like when you accelerate and let off the pedal and cruise? If so that noise would be ring & pinion.

Your noise sounds like the rear axle carrier bearings. Since the noise is constant at any road speed.

If its wheel bearings typically they will make more noise when you turn, as the body rolling onto either side increases the load on that bearing and makes it louder.

Sent from my SGH-T959 using Tapatalk

 

[homemade]

Thanks, for the reply.

Acceleration/deceleration/braking - no change. The only thing that changes is the intensity with higher speed up to about maybe 50 and a slightly higher pitch with higher speed.

I’ll probably take it in to the dealer to check it out but from what I read about from others with driveling noise problems dealer mechanics haven’t been much help to them.

It doesn’t affect drivability but I would like to avoid compounding any damage or a on road breakdown.

 

[FellowTraveler]

Thought

Before you dispel the front differential especially if noise appears to be coming from the front;

Have you opened your front differential cover to inspect the carrier, bearings, ring or pinion? I seem to remember something about those hubs not completely disengaging, maybe someone here could confirm that.

There are known issues w/many FORD front differentials using sealed wheel bearings assemblies.

 

[homemade]

Before you dispel the front differential especially if noise appears to be coming from the front;

Have you opened your front differential cover to inspect the carrier, bearings, ring or pinion? I seem to remember something about those hubs not completely disengaging, maybe someone here could confirm that.

There are known issues w/many FORD front differentials using sealed wheel bearings assemblies.

I sort of like the Ford sealed front wheel bearing assembly if only because it is such a no-brainer to replace.

The auto lock hubs definitely have issues, mostly because although you can manually lock them when you switch them to auto that doesn't definitively unlock them.

I made sure the hubs were unlocked and the front differential wasn't spinning. I even removed the auto hubs to make sure the bearing in the hub wasn't making a noise (although that bearing should only spin if the hub is unlocked and the noise is the same locked and unlocked) - no difference even without the hubs.

If/when I need to repace the hubs I'll just give up the auto hub convenience and go to warn premium units.

If I ever find out what this is I'll post up.

 

[FellowTraveler]

Good luck with it, you are on the right track w/warn hubs.