Re: AMC 20 bearing lube question
The AMC 20's outer bearings depend on being greased and if they're lubed by the diff juice, the seal is leaking and your brake shoes/rotor are wet.
I'm not sure about the Summers Bros zerk fitted bearing, they usually have pretty good stuff. What I have done on CJ AMC 20s is to drill and tap the axle housing, top and bottom for zerk fittings in the area between the bearing and the seal. The bearing on factory 2 piece axles have the bearing pressed on so the race and tapered end on the bearing are facing out. In other words, when the axle goes in, the bearing enters the housing before the race. If you're picturing this correctly, you can see when you have an axle out, that there is about 1" between the bearing and the seal. This is the area that I drill and tap.
The reason that I drill and tap top and bottom? When you grease the bearing, pull the lower fitting out of the housing and grease the top one to add grease. With the bottom fitting removed, if you "over grease" the bearing, it will allow grease to ooze out the bottom rather than forcing it's way past the seal. Make sense?
The HD AMC 20 axle, which I run in the rear of my CJ (from an 82 Waggie) has one piece axles from the factory, but the bearing and race are turned around the other way, so the race goes in first. Pissed me off. Took me years to figure out to drill and tap the housing to grease the bearing and then I switch to the HD housing and the game changes. Oh well...
BTW, use a premium grease, like marine grease, to grease your wheel bearings. I use Pennzoil Marine from Tractor Supply in the grease gun. Water will get in the bearings if you go through water. Marine grease won't break down as easily when exposed to water.
Sorry for being so long winded...
From Southeastern Indiana...Guy
CJ7, 258, T18, Dana 44s ARB/Detroit, 4 wheel discs, YJ springs w/shackle reversal
93 Toy T100 4X4 (daily driver)
1971 Jeepster Commando - all stock!