This information is directly from Superior and Moser Tech people.
(CONSIDER THIS FOR A 'STICKY'...)
IT'S ALL ABOUT THE BEARINGS YOU USE.
There are two bearing choices,
Timken p/n SET 9, and Green p/n RW-903CJ
MOSER ENGINEERING uses both Timken Set 9 and Green RW-903CJ
Moser p/n RW9CJ57
for SEALED 'Green'
Moser p/n 9CJTB
for the Timken
Set 9 Tapered Bearings
The Information from Moser is, they DO NOT use BEARING SPACER RING installed between INNER seal and bearing retainer.
SUPERIOR ONLY USES TIMKEN SET 9 TAPER BEARINGS,
(Although I'm under the understanding that Green Sealed Roller Bearings will work also.)
Superior Axle uses an INNER SEAL, Then a 'SPACER/ADAPTER' between Inner Seal and the lock ring for the bearings.
The purpose for this 'Spacer' is to keep the lock ring from rubbing on the seal.
(See 'Bearing Spacer Ring' in image above)
Use of that Spacer requires the locking ring to be machined for thickness.
(NOT inside diameter, or outside diameter, but thickness to 0.300" thick, about half of factory Timken Set 9 thickness)
Superior Part Numbers for parts,
Timken Bearing Set 9 with machined lock p/n A9
Machined lock ring p/n 3107D
Spacer p/n 3107A
Install kit, (one each) Set 9 Bearing, Machined Lock, Spacer, Inner Seal, Outer Seal, $53.05,
1 Each Per Side.
Here is the difference in the bearings...
Timken 'Set 9' are conventional taper bearings
, they have very good load handling capabilities and are up to about anything you can throw at them, including extended high speed service.
Set 9 'Snaps' together in a peculiar way, but they aren't anything that are so different you won't be able to figure them out if you are used to wheel bearings.
will be on some of the aftermarket 'Clone' axles you will have to use SHIMS to set Pre-Load,
And in ALL CASES
you will need an outer seal and you will need LUBRICANT to the Set 9 bearings.
Some people drill a hole in the inner seals so gear lube can circulate around the bearings,
Some people use both seals and wheel bearing grease.
In either case, you MUST use an outer seal and lubricant!
brand bearings are a fully spherical, round ball type bearing, not the taper bearings you are used to seeing in wheel bearing applications.
This means they will have less total load carrying capacity, so if you tow large boats, heavy tongue weight trailers, you are using your CJ as a tow truck, ect.
I'd pass on the 'Green' brand bearings.
Also, 'Green' brand bearings are SEALED BEARINGS
, meaning they don't use outside lubrication.
The good points to that are contaminants can't enter the bearing and there is no messy 'Repacks'.
The down side is there is a VERY limited amount of lubricant available to the bearing, so that lubricant will get VERY HOT during operation.
This means in most cases, if you install an inside seal to keep the gear lube in the differential housing,
You can skip the outside seal.
With no lube at the outside seal, it's just going to burn up anyway...
You can use BOTH seals, but put a small some gear lube in the bearing flange with the bearings anyway to keep rust down, and use an outside seal to keep the gear lube IN, and the mud, dust, rust OUT!