M880 Wheel Bearings Question

[Dave_1972]

So I have both my front wheel bearing assemblies removed while replacing the bearings and doing a brake job. I started second guessing myself during reassembly and now have gotten thoroughly confused by what I am reading on the interwebz about how it goes back together - to the point that I am questioning how it was put together in the first place.

***Normally I am smart enough to do one side at a time - but I thought "no problem I'm only replacing bearings on one side". Guess how that went. ***

Should there be two oil seals on each side? One on the outside and one on the inside? If so, are they both the same part (413248 at Autozone)?

Should the bearing (and outer oil seal) be pressed onto the hub-rotor assembly before installing on the truck? If so is there any catch to that? Do you just press them down as far as they can go?

TM-9-2320-266-24P has a figure 63-1 that is confusing me terribly right now. It shows outer and inner oil seals and the inner seal is a multi-piece oil slinger I think?

I don't think I have the slinger at all unless it is on the stub shaft maybe?

 

[NDT]

Follow the -20 or the instruction sheet that comes with the bearing kit. This is quite complicated as you have found out. Not one of Dana's better designs. The -20 is here on the TM area; I have a scan of the instruction sheet if you need it.

 

[dtracy22]

The inner seal was more of a lip seal or dust seal. No one makes it anymore. I've used and I've tore down other axles that had the same seal on the inside as the outside. Either way don't go without one at all.

 

[Dave_1972]

The -20 finally got me straightened out on what I was looking at in that diagram. The oil slinger was what was confusing me. Once I realized that then it all made sense again. Sadly I do think my passenger side hub/rotor assembly is worn out - when installing on the truck the inner bearing came back off - I had to press it on a second time and install again. But I take that to mean that the hub/rotor is probably shortening the life of my bearings on that side.

The good news is I have a 1973 crew cab (a Tinker AFB truck no less) with a rebuilt manual lockout hub Dana 44 under it sitting in my field. That truck is my next big project and if I were closer to getting that project started I would have swapped it out now. As it is, I suspect my bearings will easily last until I have that truck in the shop and reach a good point to pull the Dana 44 on it. (It's getting a 1991-1/2 Cummins 3/4-ton 4x4 drivetrain).

 

[jtucker]

The oil slinger you can get them I just did the wheel bearing on my m880, I called dana and they gave me a couple of number to call around for to see if anyone still had them and I was able to find them no problem.

 

[Floridianson]

Do believe the slinger is a plate that is bolted to the hub. If a seal goes the grease goes through the holes in the slinger and comes out on the outside of the hub. This keeps it off the brake shoes and off the inside of the hub. This is why when you do a hub service you check the holes are clear.

 

[jtucker]

The oil slinger is a ring that is pressed onto the axle which is what keeps the grease in hub/steering knuckle, and not all over the back side of the steering knuckle and brakes. sounds like you are thinking of the wheel seal retainer house, which bolts to the outside of the steering knuckle held in by I think 8 bolts? Could be wrong on the number.

 

[dtracy22]

They orignally had the slinger as mentioned but I've seen plenty of trucks with the 413248 seal in the inner and outer position and they seem to work just fine.