regrease a wheel hub bearing

[ehall]

Something I have wondered about for a while is if it was feasible to regrease a wheel hub bearing unit. Last week I picked up a couple of D30 shafts and they still had the bearings on them. Rusty ugly and they made some scratching noises too, but figured I would look at the feasibility of regreasing before sending them to the dump.

The orange seal on the backside pops off with a pick/awl. Don't tear it. Underneath that is a second seal that also pops out. The inner seal will bend when it's pulled out, but you can tap on it with a hammer to flatten it back out.

Underneath that is a ball-bearing race. I assume there is another race deep inside but I couldn't see it.

I used a bunch of brake cleaner to clear out the old grease and dirt. The bearing will turn much faster and looser once its cleaned, but will also make more noise. After the brake cleaner dried, I put a layer of grease on the bearings and used a pencil to force it down into the race. Then I did another layer, and another, until the grease stopped going down.

Once the grease was loaded, the two seals "snapped" back into place with just finger pressure. There was some kind of groove to hold them, probably something to make assembly faster. After they are back together, the grease makes the bearings spin slowly, but they are smooth and quiet again.

Okay so questions: Has anybody else done this and does it work? I am sitting here with about 30 min and $10 in fluids invested and if this works it will be great, but this doesn't seem like a popular thing to do (or my google-fu is weak), which makes me wonder if it won't work at all

 

[Tim_MN]

Separating the sealed unit hub bearings either ruins them outright, or leaves them open to contamination that will ruin them shortly. When failed or noisy, they are simply replaced.

 

[ehall]

I didn't separate it, I just popped off the seal

 

[cruiser54]

ehall, I've done that on smaller bearings like idler pulleys and the like with excellent results. Pretty much refreshing the grease.

 

[kndrewa]

On that note, do they HAVE to go to the dump?
Is there a place to recycle old hub assemblies?
I've got 3 or 4 of them laying around, but it seems awful to throw that metal out.
I suppose I just answered my own question - find a metal recycling facility in my neighborhood.

 

[Talyn]

Any steel recycling place will take the hubs. They may even give you a few cents for them as well as any scrap metal sitting around.

 

[kastein]

Hubs are damn near 100% metal by weight, the scrapyard will be happy to take them. Grease and rubber will melt/burn off fine in the smelter.

I think this will definitely help, especially if you do it before the bearings become pitted and worn from all the wear particles, dirt and water that finds its way into there.

 

[foxwar71]

Ive heard that some of the Ford and Dodge truck guys make up ways to regrease their unit bearings. On units that have the ABS sensor and stuff built into it, they unbolt the ABS sensor and pump grease into the inside of the bearing from there. Some have said this has inprove the life of their bearings. I wonder if its possible to drill & tap a bearing for a grease zerk so you can pump some grease in it occasionally? Seems like a good idea in theory.

 

[kastein]

I wonder where a good location to drill into the bearing would be. I can't think of any... and how would you get the shavings out afterwards?

 

[foxwar71]

I wonder where a good location to drill into the bearing would be. I can't think of any... and how would you get the shavings out afterwards?

:dunno: Just an idea!!

I would coat the drill bit and tap in grease and use a magnetic to keep the shavings from going into it. It would just be like the same as other things that get drilled/tapped without getting stuff inside, quickest example I can thing of is drill/tap a hole for an EGT sensor on an exhaust manifold on a diesel.

 

[kastein]

:dunno: Just an idea!!

I would coat the drill bit and tap in grease and use a magnetic to keep the shavings from going into it. It would just be like the same as other things that get drilled/tapped without getting stuff inside, quickest example I can thing of is drill/tap a hole for an EGT sensor on an exhaust manifold on a diesel.

works for me! I'd just hate to wreck a bearing trying to keep it from getting wrecked.

 

[ehall]

I was going to drill and tap in the space between the two bearing races (guessing on there being a 2nd race and it's approximate location) but I don't have a 1/4-20 tap

Any junker hub unit will work for testing purposes. Drill a hole. Look inside

Getting the shavings out with the brake cleaner is probably feasible.

 

[ChiXJeff]

:dunno: Just an idea!!

I would coat the drill bit and tap in grease and use a magnetic to keep the shavings from going into it. It would just be like the same as other things that get drilled/tapped without getting stuff inside, quickest example I can thing of is drill/tap a hole for an EGT sensor on an exhaust manifold on a diesel.

There's more than a little difference between drilling & tapping holes in a bearing race vs. an exhaust manifold upstream from a turbo. Chips actually stand a fair chance of getting blown through a turbo without damaging seals. Chips in a bearing have nowhere to go.

Ideally, drill in between the inner & outer races, and avoid the rolling elements. I would not drill through the races where the rolling element surfaces are.

 

[kastein]

That's about what I was thinking too, I'm just not sure how I'd get any leftover bits out. You'd really want to get EVERYTHING out because any fragments left would get pulverized by the bearings... ideally this could be done on one of the old spindle style d30 hubs from the RENIX era, while the hub is disassembled, but I'm not sure how to do it on a later model hub. Maybe find a way to use compressed air and some light solvent like diesel or brakleen to flush everything out through the zerk hole after drilling/tapping?

 

[ChiXJeff]

The grease trick in the flutes is probably the best bet, but anything left will destroy the bearings in pretty short order.

 

[Matthew Currie]

I thought about adding a fitting once long ago, and I've forgotten the details now, but I think I determined that the proper location for the fitting would put it in a spot you can't reach with the hub installed. If I have a chance, I'll have to reinvestigate that, because I think I have a dead and disassembled hub somewhere in my junk pile.

I have regreased a hub that I accidentally pulled apart with a slide hammer during a u-joint replacement, and although it already had very high mileage it lasted a while longer. If your hub is near the end of its life anyway, there's little to lose by experimenting.

 

[my2monkeys]

Sounds like a reasonable idea, that's what they want you to do on C/V axle joints (clean old grease out and put new in).

Although it's a lot different bearing design on the C/V assembly.

What kind of grease did you use on the unit bearing? Typical whealbearing grease?

I wonder if that C/V axle grease would be good, it's pretty thick and won't spin off.

Ofcourse that pretty much describes most wheel bearing grease now doesn't it.:gee:

 

[Matthew Currie]

Sounds like a reasonable idea, that's what they want you to do on C/V axle joints (clean old grease out and put new in).

Although it's a lot different bearing design on the C/V assembly.

What kind of grease did you use on the unit bearing? Typical whealbearing grease?

I wonder if that C/V axle grease would be good, it's pretty thick and won't spin off.

Ofcourse that pretty much describes most wheel bearing grease now doesn't it.:gee:

My main source of ball bearing wisdom is rather old fashioned (a long-outdated New Departure Handbook), but ball bearings haven't changed much in the last 50 years or so. Anyway, the traditional wisdom is that lubricants containing solids should not be used in a close tolerance ball bearing, because the solids will provide an obstacle that must either be pushed aside or rolled over. Moly grease is meant for high impact and sliding applications, but may not be optimal for ball bearings. I'd stick to a good high temperature grease.

If I suspected that I might have compromised the seals by opening the unit, I'd try boat trailer bearing grease, which tends to be very smooth and water repellent. I've had good luck on other bearings with Sta-Lube boat trailer grease.

 

[Super mud]

ideally this could be done on one of the old spindle style d30 hubs from the RENIX era, while the hub is disassembled, but I'm not sure how to do it on a later model hub. Maybe find a way to use compressed air and some light solvent like diesel or brakleen to flush everything out through the zerk hole after drilling/tapping?

So whats the difference in the renix hubs? I have a renix and all iv noticed is i cant put my rotor on a newer unit bearing.

 

[kastein]

So whats the difference in the renix hubs? I have a renix and all iv noticed is i cant put my rotor on a newer unit bearing.

I've been lead to believe that they can be disassembled and rebuilt, I could be wrong on that.