CheapXJ said:
how do the kunckles have a different offset?
if that was true, then wouldn't the resultant swapping also put the axle u-joints out of alignment and need to be addressed with spacers such as used when swapping WJ knuckles on?
discard the early knuckle from the discussion (the one with the bolt-on caliper bracket)
since they appeared as late as 93.
so ALL knuckles from 93 on up (excluding WJ knuckles) are the same.
and all bearing hubs from 93 on up are the same.
yet, this happens:
http://www.naxja.org/forum/showthread.php?s=&threadid=1800
I remember reading about THREE different offset bearing hubs on the old forum about two years ago.
so what is the difference? there is SOMETHING that HAS to be DIFFERENT.
Sean? what is this third hub that you speak of? I'm pretty sure it was you who told me the measurements and everything way back when.
This is what I know from experience:
Bolt a late model hub on the early knuckle with early rotor and the rotor hits the knuckle. The late hub/rotor face to the bolt flange distance is offset in, compared to the early hub. I believe this is the "shorter" hub mentioned in all these posts. Add washers under the rotor to hub flange, more than one or two washers, and the alignment can be "shimmed" back to "normal" for the early knuckle.
Take the above configuration, and replace the early rotor with a late rotor. Early knuckle, late hub, late rotor: and the rotor disc moves out ~1/8" (less "shimming" is required, but still required).
I have not tried fitting an early hub (with either rotor) on the late knuckle on an assembled axle.
I do know the late rotor will not seat on the early hub flange (tried with spares and it did not fit).
The axle shafts are the same length.
The late hub thickness, flange to knuckle flange distance, is ~1/4" less (appears to move the hub/rotor flange inboard when bolted on the early knuckle).
The late knuckle/hub flange to ball joint centerline is ~1/4 wider. The mounting flange on the knuckle is offset outboard the same change in distance as the reduced thickness of the later hub.
The late rotor centerline to hub flange is ~1/8" less (the composite rotors I have). DC offered a cast one piece late rotor as an option to replace recalled composite late rotors (1997 or 1999). The late rotors are offered in cast or composite construction, the early rotor is only cast construction. None of these rotors are considered thick enough to machine (they are cheap and intended to be replaced when the wear thin or warp).
My experience is that bolting unmatched parts together can place the rotor centerline 1/4 and 1/8 inboard of where you want it on the early knuckles.
I imagine the bolting early hubs on the late knuckle will place the rotor centerline ~1/4 out, or ~1/8 out with a late roter (if you could get it to seat properly, but it will not due to center hole and flange radius machining differences).
The mix of the two rotor/hub/knuckle combinations can place the rotor centerline 1/4 and 1/8-inch inboard, centered where Dana designed the axle assembly, or 1/8-inch outboard (if the early rotor was machined to seat on the late hub flange) and 1/4 outboard. Five rotor centerline offset combinations from two different knuckles, two different hubs, and two different rotor designs.
I believe this explains what everyone is seeing in the various posts (all except a parts vendor trying to pass early rotors as late rotors)?
