Dragging metal noise

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So the axle itself is fine as is the housing.

the pinion and ring gear are sloppy and the axle bearings are toast.

They are going to rebuild the rear diff, new ring, new pinion, new axle bearings and seals...

universal joint is ok as well.

there are only two things gonna cause this.... I’ve never towed with the truck... never hauled more than 250lbs in the bed...

so it’s the added horsepower and maybe I guess you can argue that the angle of the driveshaft is changed due to the level up front.... couple that with the heavier tires with 1.5” offset and I think you have more wear and tear than it’s designed for.







The rear axle is the Ford Corporate/Sterling 9.75"; in general it's a very strong axle. What exactly failed?
 

FordTechOne

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So the axle itself is fine as is the housing.

the pinion and ring gear are sloppy and the axle bearings are toast.

They are going to rebuild the rear diff, new ring, new pinion, new axle bearings and seals...

universal joint is ok as well.

there are only two things gonna cause this.... I’ve never towed with the truck... never hauled more than 250lbs in the bed...

so it’s the added horsepower and maybe I guess you can argue that the angle of the driveshaft is changed due to the level up front.... couple that with the heavier tires with 1.5” offset and I think you have more wear and tear than it’s designed for.

Thanks for providing the additional details.

The mods you listed shouldn't cause axle bearing failure; axle bearings only fail from a lack of lubrication, contamination (bad seal, water intrusion from off road use), or vehicle overloading. You mention you changed the gear oil with Amsoil; what viscosity and quantity? Is the diff cover factory or aftermarket?

As far as the pinion bearings, similar failure modes; however excessive torque and improper pinion angles can certainly cause bearing failure.
 
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75W140 severe gear oil.
full synthetic

it’s a FOMOCO Ford Performance Diff cover.
I got it for the convenient drain and fill plugs.

The truck has never been off road. Certainly a seal could have failed.

the driveshaft angle is changed due to the 1.75 inch collars. The torque is what it is... I’m about maxed out with a tune and bolt ons.

admittedly there is some additional torsional forces in my penchant for burn outs.


Oh I should add this wasn’t a warranty item. I brought it to the dealer with tune flashed, all the mods in full glory. I’m not looking to beat Ford out of a few bucks. I’m pretty sure I wore the rear end out Prematurely anyway.

1900 to rebuild the rear diff. It’s a small price to pay for the joy it has brought Me. :)
 
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Axle bearings are toast and slop in the r/p? Sounds like it was starved of oil. Like your bearings went away.
 
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I pulled the diff cover when the noise started. It was full of fluid. I didn’t closely instect the gears because I honestly didn’t expect that to be the issue with 31k miles.

but it wasn’t run out of oil that’s for certain.
 

GCATX

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I pulled the diff cover when the noise started. It was full of fluid. I didn’t closely instect the gears because I honestly didn’t expect that to be the issue with 31k miles.

but it wasn’t run out of oil that’s for certain.
Maybe it's like you said the pinion angle took the oil slinger, if it has one, out of the oil level. Doesn't seem likely. I do know that many rear ends just randomly go out though, across all truck lines. There are a bunch of things that can go wrong setting up gears, but everything does have to go right. I would chalk it up to a bad bearing set, metal shavings probably took out the other bearings.
Does the new diff cover have a magnet on it somewhere to catch floating metal?
 
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The FOMOCO rear diff cover has magnetic drain plugs.

It’s handy if you keep your oil changed frequently. In my guess that didn’t make a difference.

It could just be bad luck that it went bad.

Either way the dealership is solid. I trust they will rebuild the diff well. They mostly sell and work on trucks

Maybe it's like you said the pinion angle took the oil slinger, if it has one, out of the oil level. Doesn't seem likely. I do know that many rear ends just randomly go out though, across all truck lines. There are a bunch of things that can go wrong setting up gears, but everything does have to go right. I would chalk it up to a bad bearing set, metal shavings probably took out the other bearings.
Does the new diff cover have a magnet on it somewhere to catch floating metal?
 

K1llD4shN1n3

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So the axle itself is fine as is the housing.

the pinion and ring gear are sloppy and the axle bearings are toast.

They are going to rebuild the rear diff, new ring, new pinion, new axle bearings and seals...

universal joint is ok as well.

there are only two things gonna cause this.... I’ve never towed with the truck... never hauled more than 250lbs in the bed...

so it’s the added horsepower and maybe I guess you can argue that the angle of the driveshaft is changed due to the level up front.... couple that with the heavier tires with 1.5” offset and I think you have more wear and tear than it’s designed for.
This is exactly what just happened this week in my truck. Waiting for them to finish up the work to fix it today. Didn’t go with a dealer or try to get the warranty to cover it as it would have meant weeks of down time.


Sent from my iPhone using Tapatalk
 
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weird.


This is exactly what just happened this week in my truck. Waiting for them to finish up the work to fix it today. Didn’t go with a dealer or try to get the warranty to cover it as it would have meant weeks of down time.


Sent from my iPhone using Tapatalk
 
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