Are these bearings bad?

[BeerBrewer]

I took apart my wheel hubs today, so I could inspect and re-grease my wheel bearings and I'd like to hear your opinions on my bearings. They both have a discoloration on the inside of the bearing. The bearing on the left (inner bearing) has a brown discoloration on the inside. The other bearing (Outer) is similar markings, but only more pronounced. Is this what they call fretting? Otherwise the bearings look perfect, there isn't any pitting, scratches, mars, dents, they just seem perfect. The races and spindles also look fine, no scratches, no discoloration, no nothing.

Do I replace?

Thoughts?

[4x4dually]

EDIT:

Now that I've had time to think about it, in my experience....once I've "washed a bearing out" they won't last for crap. Not sure if I don't keep them clean enough or not pack them correctly or what. I've never had much luck with re-using them if I wash them clean. I typically just take them out and pack more grease in them and re-install. Not sure if that helps ya much.

[Second Chance]

The photo is too small for me to see if there is any pitting or discoloration from overheating. That said, I serviced bearings for 50 years by cleaning them thoroughly with a solvent to remove old grease, moisture and debris. I then blew them out with a compressor and "sun-dried" them for several hours. I then repacked them with a packing attachment on a grease gun (when I was young, I used the palm of the hand method my dad taught me). After reinstalling the bearings and hubs (with new grease seals every time), I made sure the castle nut was torqued and backed off properly. I never had any issues with bearings not lasting - even on boat trailers that were submerged. I now have our favorite mobile tech do bearing service. He takes the bearings and hubs to his shop where he has a parts washer, but he follows the same procedure I outlined above. No problems with his bearing services, either.

Rob

[Jerryr]

As Rob said, I have thoroughly cleaned out bearings using a parts washer with filled with mineral spirits, blowing them out with compressed air and letting them sun dry. Then I still repack by hand using the palm of the hand method with 3 pairs of nytril gloves on each hand. New seals and reassembled.

I've occasionally in the past even used a coffee can filled with gasoline to get them really clean. That was when I was young and dumb.

Heck over a half of century ago I even used Jet fuel dripping from F-4 Fantom fighter jets to fill my Zippo lighter.

[Hoopy Frood]

This is partly my feelings after many years working with bearings and such, but I'm totally against completely degreasing bearings. High carbon steel can rust extremely quickly. Mineral spirits will completely remove grease film and expose the steel to any atmospheric moisture. And it serves no purpose, the longer the bearing is exposed, the more likely it is to be contaminated. There's a reason they come packed in greased paper. Like I said, just my feelings about the subject.

[jjbbrewer]

At $20-30/pair, I'm more inclined to just replace them, rather than try cleaning & inspecting.

Is there a downside to doing that?

[BeerBrewer]

The photo is too small for me to see if there is any pitting or discoloration from overheating. That said, I serviced bearings for 50 years by cleaning them thoroughly with a solvent to remove old grease, moisture and debris. I then blew them out with a compressor and "sun-dried" them for several hours. I then repacked them with a packing attachment on a grease gun (when I was young, I used the palm of the hand method my dad taught me). After reinstalling the bearings and hubs (with new grease seals every time), I made sure the castle nut was torqued and backed off properly. I never had any issues with bearings not lasting - even on boat trailers that were submerged. I now have our favorite mobile tech do bearing service. He takes the bearings and hubs to his shop where he has a parts washer, but he follows the same procedure I outlined above. No problems with his bearing services, either.

Rob

I'm not sure why the pic is so small, but if you tap on it, it enlarges a bit.

I hope that helps.

Bob

[4x4dually]

At $20-30/pair, I'm more inclined to just replace them, rather than try cleaning & inspecting.

Is there a downside to doing that?

Bingo. Might be stress fractures you can't see. Just start over since you've got them completely apart. $.02

[BeerBrewer]

Unfortunately, I went to three auto parts stores in my area and only one store had anything in stock. Believe it or not they only had one set of "Duralast" bearings in stock and I would have liked at least two sets. I never heard of Duralast bearings, but they claim to have a life time warranty. I am going to order some Timken bearings online. But in the mean time I picked out what I thought were the best bearings and used them on the last axle. I didn't want to leave my trailer on jack stands, while I waited for parts. If the new ones come in time, and I have time I'll replace them.

I seriously doubt that my old bearings have stress fractures. To me it looks like the little grease that was between the spindle and bearing got heated up and may have burned a bit, but I'm no expert. The bearings them selves and the races show no sign of wear at all. When I took the pic, the bearings were still a tad dirty, I was more concerned about the discoloration.

[Hoopy Frood]

I'd bypass any auto parts stores, and head to a bearing warehouse/supplier, like Grainger, MSC, or Fastenal.