68' Front disc brake conversion question

Hey all,

Just got done swapping over the front drums to disc following the procedures outlined here through lots of different threads. I had a quick question to see if anyone has encountered this.

I used caliper brackets from Bronco graveyard, new rotors, the late 70's Chev truck calipers, and used the 501311 inner "conversion" race that everyone says makes everything line up right. Everything goes together fine other than that now the rotor / hub has been moved out so far that I am unable to get the snap ring on that goes right at the end of the axle shaft on both sides, that ultimately secures the inner part of the hub to the axle before the 6 hub bolts go on. I'm unsure exactly how important this is, without it the axle itself can move in and out about 1/4 inch, but nothing else happens and it doesn't appear to be detrimental. Obviously though, it's there for a reason. Hubs still engage fine and everything else appears ok (I went ahead and put everything back together without them for now. It appears that I need an additional 1/8 inch or so to get be able to get the axle end out far enough to expose the slot the snap ring is supposed to go in. I could accomplish this by machining more material off of the hub face that rests against the rotor, but this would require complete disassembly again, pressing all the studs out, etc. It almost seems like the conversion race has caused this, but just about every story I've read has said that without that race, the rotor rubs the bracket.

Anyone else encounter this?

 

Yes I've encountered it and you can run without the snap ring. I've done many of these conversions and due to spacing the hub out to make everything work there is no way you will be able to use that snap ring. I've been running mine 15-18 years without them with no problems. I have tons of customers running them this way with no problems also.

 

Thanks man, I appreciate the help!

I assumed it would be ok, as there's really no place for the axle to go other than 1/8 inch or so.

Also, one other very small issue, if issue at all...the brake pad surface itself sits about 1/8 inch off the edge of the rotor once everything is tightened down, where the pad edge should really sit about 1/16 inch in from the edge. Not a huge deal, there will just be a small part of the pad not making contact with the rotor. Is this common?

 

Common with some aftermarket pads. If you are not running a power booster make sure you are using organic pads. If no booster and running semi-metallic pads you won't stop very well as the pad friction material is too hard.

 

Yep, got organic pads...

Hey one more thing for you...

I replaced the master cyl with a Fenco replacement (I work for a parts company) and did not see a residual valve in the rear port (to the front). Interestingly enough, the M1292 Master Cylinder for a 68' Commando runs all the way through the 70's and is used on a 76' CJ5 with disc brakes...so I'm not sure how in the world that's possible without a residual valve in that port, unless the original one on the Commando had one in it and no one ever replaced it, because it wasn't there when I took the old one off. Any ideas?

Do you think I'll still need a 2lb up front or just wait and see what the brakes feel like?