Plan to repack and/or replace my front wheel bearings in a week or two. After reading the threads online and a couple of DIY pages, I have a couple questions about where the grease goes:

1. I expect to grease the inner surface of the oil seal (the side that contacts the king pin). Do I also need to grease the outer surface of the oil seal and/or the races before installation? Or should these be dry?

2. Grease goes in the bearings and in the space between the inner and outer bearings. Do I also need to put a little grease in between the seal and the inner bearing, or is this not really necessary?

3. I imagine grease goes on the kingpin as well, before sliding the bearings and hub onto it.

I'm sure all of this will probably become self-evident once I have everything off, but I haven't done this before, and I always like to visualize the more important jobs before trying them the first time. Thanks in advance.

Anthony

You are headed in the right direction...

WITH that many miles on the original bearings I would replace them!

ALSO the key to long bearing life is getting all of the componets CLEAN ....& using a high quality high temp grease!

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There is a specific amount of grease you should shoot for, not completely filling the cavity. I wouldn't go nuts trying to match it, but that and the procedure for adjusting the play should be followed. Do change the seal, but I would only change the bearings if they are damaged or worn. This is the best guide I have ever seen describing common bearing failures: http://www.bardenbearings.com/scan%20pdf/Bearing%20Failure%20Brochure.pdf

Also, you can wash the bearings out in kerosene and then a little rubbing alcohol before blowing them dry and greasing them, but do not use the air to spin the bearing cage around the race.

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'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

Plenty of good advice, the only thing I might add would be to buy a little plastic gizmo for packing the bearings . Any auto parts place has them. You put the bearing in, attach your grease gun and pump.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Seals should never be installed dry. Make sure to butter the surfaces for easy installation. Otherwise, the exterior surfaces outside the seal area should be as free of grease as possible.

Adding grease between the seal and inner race is also a good idea. After packing the bearing I like to add more grease to the sides of the races.

The basic idea is to pack as much grease as possible in and around the rollers. The remaining interior surfaces only get buttered.

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95 E320 Cabriolet, 169K

Thanks for all the advice. I managed to finish the job this weekend - man what a pain. Took me over six hours to do the first one, thankfully the second one went a lot smoother. Interestingly, althought there was noticeable play at both front wheels, the adjusting nuts on both hubs seemed to be pretty tight. I ended up tightening the new bearings to basically the exact same spot as the old ones.

Anyone interested in some wear analysis? Based on examining the dust cap and the hub, I think these bearings might've been repacked once in the first 100,000 miles, but certainly not in the last 200,000. The grease was a tan color, except around the bearings, where it was black, and the left inner bearing, which has some reddish-colored grease. I think the grease seal might've failed.

Left to right: Right inner, right outer, left inner, left outer.

Attached Thumbnails

       

Hi there,
They didn't get discolored from the grease, that's for sure! They were running very hot at some point, either from running to tight or lack of lubrication. It's a good thing you changed them out!

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Richard Wooldridge
'01 ML320
'82 300D 4.3L V6/T700R4 conversion
'82 380SL, '86 560SL engine/trans. installed
'79 450SL, digital servo update
'75 280C

Hmm. Well they seemed pretty well greased, but I guess if that grease was oxidized then maybe it didn't lubricate very well.

I basically ended up with the lock nut in the same position (same preload?) as they were originally. What I did was tighten the nut down hard with a crescent wrench, then loosen, and hand tighten it snug. I could move the washer with a screwdriver, but not my fingers. I couldn't tell a difference in how freely the hub spun with the nut tightened this way vs. loose, so I assumed that it wasn't too tight.

I analyze bearings for a living on a daily basis. You changed them just in time. Richard is correct, the discoloration on most of the races indicates localized overheating. This is probably from the oxidized (black) grease that was plain used up.

I'm not sure what to make of the reddish-colored grease, except that you're probably correct in assuming the seal failed, allowing water to creep in.

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95 E320 Cabriolet, 169K