Pinion bearing/flange interference

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BlackMagnum2000

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Alright so I finally narrowed down my noise (whining/howling at 15+mph in any conditions) to the rear end. Pulled the cover to find a TON of metal.
e158a415ed55933e9cccc2244189aad0.jpg

Start tearing it apart.
Pattern is fine. Gears are fine. Races fine. Bearing rollers are fine.
I finally found a spot on the outer pinion bearing where there was a small groove. On the pinion flange, there are small grooves and a lip on the inner edge. Do you guys think this is my problem? And also, what would cause this? I understand the damaged flange could damage the bearing, but how would those grooves develop on the flange in the first place?
948576defa1bfd77cd38b2dacbe0c06e.jpg

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jbmobbs

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From where the bearing is sitting still and the pinion is moving.

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dudeman2009

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I've seen similar things happen when people don't properly set the preload on the pinion when doing repair work, but not outside of that. To me it would appear that something cause that bearing to lock up either fully or partially. Looking at the picture the inside of the bearing and the outside of the pinion look chewed up too.

I'd say most certainly that bearing has hit some resistance and got screwed by the much harder pinion. I cant see in the picture all too well, but it looks like there is rust on parts of the pinion that are exposed only to the inside of the differential.

The fluid looks like it is filled with water. Sure some of the foaming will come from agitation of the differential, but thats just too far to be anything but water. If I had to guess, water go into the differential, either cause rust that broke free and jammed the bearing, or prevented the oil from properly lubricating the bearing and that caused it to jam.

That looks like a lot of water, have you submerged the axle in the past year?

You should be fine just to replace the bearing, and put everything back together, the pinion doesn't look damaged enough to warrant replacement. Personally, i'd replace the axle seals as well, you might have to buy the tools to do it if you cant make your own, but they aren't too expensive and its much cheaper than paying a shop.
 
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BlackMagnum2000

BlackMagnum2000

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I've seen similar things happen when people don't properly set the preload on the pinion when doing repair work, but not outside of that. To me it would appear that something cause that bearing to lock up either fully or partially. Looking at the picture the inside of the bearing and the outside of the pinion look chewed up too.

I'd say most certainly that bearing has hit some resistance and got screwed by the much harder pinion. I cant see in the picture all too well, but it looks like there is rust on parts of the pinion that are exposed only to the inside of the differential.

The fluid looks like it is filled with water. Sure some of the foaming will come from agitation of the differential, but thats just too far to be anything but water. If I had to guess, water go into the differential, either cause rust that broke free and jammed the bearing, or prevented the oil from properly lubricating the bearing and that caused it to jam.

That looks like a lot of water, have you submerged the axle in the past year?

You should be fine just to replace the bearing, and put everything back together, the pinion doesn't look damaged enough to warrant replacement. Personally, i'd replace the axle seals as well, you might have to buy the tools to do it if you cant make your own, but they aren't too expensive and its much cheaper than paying a shop.

Preload was set within spec. No way for there to have been water in it, fluid was changed weeks ago and the truck hasn't even been out in rain since. Let alone off road/submerged in water.
Possibly just the picture, but the pinion was not chewed up at all. No rust on it either. Possibly just bad lighting in the pictures.
Also, axle seals are not leaking. And as stated, there wasn't water in it. The picture of the fluid was a screenshot from a video from snapchat lol, so take what you see with a grain of salt. It was just to show how much metal was in it. All very fine metal, by the way. No big chunks.
 
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BlackMagnum2000

BlackMagnum2000

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I've seen similar things happen when people don't properly set the preload on the pinion when doing repair work, but not outside of that. To me it would appear that something cause that bearing to lock up either fully or partially. Looking at the picture the inside of the bearing and the outside of the pinion look chewed up too.

I'd say most certainly that bearing has hit some resistance and got screwed by the much harder pinion. I cant see in the picture all too well, but it looks like there is rust on parts of the pinion that are exposed only to the inside of the differential.

The fluid looks like it is filled with water. Sure some of the foaming will come from agitation of the differential, but thats just too far to be anything but water. If I had to guess, water go into the differential, either cause rust that broke free and jammed the bearing, or prevented the oil from properly lubricating the bearing and that caused it to jam.

That looks like a lot of water, have you submerged the axle in the past year?

You should be fine just to replace the bearing, and put everything back together, the pinion doesn't look damaged enough to warrant replacement. Personally, i'd replace the axle seals as well, you might have to buy the tools to do it if you cant make your own, but they aren't too expensive and its much cheaper than paying a shop.
Looking back at the pictures, in the back back ground of one picture is the flange that is dirty if that's what you were seeing that looked like rust.
The pinion might look bad in the picture but that's just from the angle I suppose
e559c1a8a7da2bc43ba0a11d0144618e.jpg

After looking at it in better light, there are some slight marks on the bearing rollers. Not much, but I'm replacing them regardless. Figure it's probably from the metal in it, as all the bearings look the same. So I'm replacing all four bearings and races, as well as taking the flange in to machine it tomorrow. Hopefully this will take care of my issue
 

dudeman2009

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Looking back at the pictures, in the back back ground of one picture is the flange that is dirty if that's what you were seeing that looked like rust.
The pinion might look bad in the picture but that's just from the angle I suppose
e559c1a8a7da2bc43ba0a11d0144618e.jpg

After looking at it in better light, there are some slight marks on the bearing rollers. Not much, but I'm replacing them regardless. Figure it's probably from the metal in it, as all the bearings look the same. So I'm replacing all four bearings and races, as well as taking the flange in to machine it tomorrow. Hopefully this will take care of my issue

I take it back. The pinion looks clean. If you say there wasn't water in it, i'll take your word for it. Still, thats a weird color consistency for gear oil. Was there friction additive in it?
 
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