Hey guys little help here. 2004 F150 New body style
it has a 9.75 with 3:55. We'll the clutch packs were going out. I put the Lightning clutch packs in for better take off. They were not that hard to put in. Reading what I have read. We never soaked the clutches and of course they made one hell of a noise. Noise finally went away in a couple of days. 2 weeks later I have a loud hum. Thought it was the actual bearings change those not it. Pinion gear is solid. So could the humming be coming from not soaking the clutches.
Any ideas

 

Did you use 75W140 synthetic lube with 2 bottles of XL-3 modifier?

 

I don't think the hum is coming from the clutch pack. You may have a axle bearing going out or even a differential bearing. If you rock the truck side to side, does the noise change? Listen carefully and see if you can tell if it is coming from one side of the truck.

 

Yes I did use the differential oil and the additive. I have changed the axles bearings. Driving down the road at 55 if you swing the truck to the right the noise stops for a second and then comes back if you go to the left the noise stays

 

It's probably an axle bearing or front wheel bearing if the noise changes when you turn right. Listen carefully to determine if it is coming from the front or rear.
I had a wheel bearing noise in the front that got louder when i turned right loading the left front hub. The left front hub was changed and the noise went away. A couple thousand miles later, the noise came back and got louder when I turned right the same as before. This time it was the RIGHT side bearing hub which confused me for a while. Evidently, it depends on whether the inside or outside bearing in the hub is the one failing that determines if the noise goes away when loaded. Bottom line is that if the bearing is bad in the front, you may not be able to tell which side has the bad bearing based on turning right and left loading and unloading the bearing hubs.

 

Ok I guess I'll jack up the back end and see where it's coming from. 2 years ago I replaced the front ones. The front ones are all enclosed no access to the bearings