Tiny chip in ring gear. (rear differential)

Asking this is the off-roading section, as I expect people here have more experience w/ broken differentials.

I broke my diff a few months ago. Got a new one. Have been breaking it in. I finally drove it enough to change the fluid, so did that. A friend gave me a little inspection scope, so I decided to have a look inside. I found one small chip on one gear tooth. I rotated my axle to get a look at all the teeth, and only this one has this minor damage.

I'm wondering if this is anything to worry about. I have no symptoms of problems. I wouldn't have noticed if my buddy didn't give me this scope to play with.

The company will give me a new differential because of this. But........ I'm getting ready to leave for my winter vacation in my truck. Hoping to drive a couple thousand miles. Don't really have time to install a new diff, and definitely can't break it in properly before I go.

I've seen pics of people discovering far worse when they look at their gears. But I also know the worst case scenario of my rear end locking up on the highway.
Thinking about this from a technical perspective... Is this tiny chip a concern? I did see the chip on my drain plug magnet, so the little piece of metal isn't in there anymore.

Thanks for any advice
I have asked several professional mechanics I know, and the responses have been 50/50, no problem, or I'd not drive w/ that... heh. (It was the older guys (50's) who said no problem, and a couple younger guys (20's) who said noway.. maybe I should consider the experience level..)

(FYI, the black looking areas on the below photo are actually mirror finish. They're reflecting all the light away, at this angle. But from another angle, you can see, those sections are mirror smooth)

 

Ok 60 + here.

As long as you managed to get the chips out . You did!

Magnetic drain plug for the win.

Being a mechanical part who knows myself I would throw the new differential in the Truck take it along .

We seem to be a pretty good group of people. I know if you were close to me I would have no problem helping to swap things.

Planning to drive to the Panama Canal?

If the differential starts to scream swap it out. Then I drove them screaming waiting for it to die another 50,000 miles.

It all comes back to you . If your worried about the differential exploding your vacation will be miserable

I have driven some differentials with far more damage then those little chips

Good Luck no matter what you decide

 

Thanks for the reply.

I did think about bringing the other diff.... I just don't have a lot of room, when packed up for a long trip. I will tell someone where the other one is, if I don't bring it, so they can ship it to me in a worst case scenario.. But I'll likely be far from civilization, so not sure if that will really work out.

I am not really worried about it. I think I'll drive my truck a lot before I go, and check on the chips again.. as long as nothing has changed, I'm comfortable with it. I'm not worried about it slowly degrading.. If it dies that way I can deal w/ it. I'm worried about catastrophic failure locking up my rear end at highway speeds, but I don't see how that could happen. There are no signs of fractures or weak areas which could break off a major chunk. If that chip did decide to keep chipping away, I don't think the small pieces would be a major concern.. They'd get stuck to the magnets or slowly mess w/ the bearings and things which would give me plenty of warning. And I don't think it's going to get worse. (although I don't know what caused it in the first place.. I do have theories. I hear gears are weak at first and basically case harden themselves.. and I did have one emergency traffic maneuver one of the first days I drove it after the new gears. Or I guess possibly there was still metal in it from my initial failure which got between the teeth. (but I really don't think so.. It had been cleaned, filled and drained a few times since then))

Ha, not to panama, but to the desert out west.. from the midwest. That's 2-3k miles round trip.

 

At work, we would scrap that out no question.

For a Tacoma, given the power levels and RPM those gears see, you're probably okay for a while. Eventually, over a long enough timeline, you will develop cracks along those small chips and cause a failure - but again, I think you're probably fine for your trip.

 

Thanks for the reply.

but...... I think I'm an idiot, and those chips aren't actually chips. I think those are oil drips and it's just an optical illusion w/ the light.

I drove it for a few hundred miles, and put the scope back in to get another look. Now I have a little experience w/ the scope, so thought of ways to get a better shot. I lifted the rear and rotated the driveshaft so I could put the camera in a good position and look at each tooth as it passed. And... There are no chips. This time I had a good angle, with much better light. Could clearly see each tooth. It was hard for me to believe, after worrying so much about it. But I've quadruple checked with multiple recordings. No chips.

 

My only advice would be to take a look at the actual chip you found on the magnet. Should provide some clues as to where it came from.

It amazes me with todays tech we can have 40+mp / 8k cameras in our pockets, but cant develop a half decent borescope

 

Is the pinion gear good?

I'd probably fill it with 85-140 and send it as long as you're not loading it up in 4 low or towing

edit: it's possible it was a chunk of the diff you blew up that found its way out later too. I pulled a third out and had more broken teeth pieces in the pan than were accounted for on the R&P that came out.

 

I can't get the scope around the locker to see the pinyon.

I don't know about the chip I found.. And unfortunately don't have it anymore. I had some shavings on the magnet as well, but was told those are perfectly normal. Maybe the chip was a shaving that had gotten tumbled around and balled up. Or maybe it was from the previous damage.. All my spider gears were stripped completely, so there was a lot of metal in it. But it had been cleaned by the toyota dealer before they realized it was aftermarket gears, and didn't want any more to do w/ it. Then a 2nd shop fixed it well enough for me to drive it back to my city (put in new spider gears, but didn't want to figure out why it was whining). Then I drained the fluid again when I installed the one I've got now. So I don't know...
I did put a strong neodymium magnet in both the fill and drain plugs, so they should grab anything else that might be in it.

 

If you never had the camera you would have no idea !!