I just finished my SAS. I used IFS hubs, re-drilled fj-60 rotors to mount the same as stock IFS rotors would with the 6 bolts, and used IFS calipers mounted on the outside of the ears. There are a few write-ups on this. I have an up and down vibration in the steering wheel on hard braking at highway speeds. I don't feel it under light braking, or at lower speeds. Everything seems tight, and they are new rotors. Any thoughts? I don't get any side to side shimmy at all. I have 4" Marlin springs with the bottom two leaves taken out, Marlin Hi-Steer, and the same rims and tires I had before the SAS. I reused my (now modified) calipers and pads. It stops fine,, and on a straight flat road stops very straight. I feel the vibration more in the wheel than I do in the pedal.
Anyone experience this as a result of anything just inherently related to the SAS, or do I need to do a better job of re-drilling fj-60 rotors? The bolts are torqued properly, but I know that the holes are not as perfect as they should be, but stock IFS rotors have play in the bolt holes, and since they center with the hub, I don't think that the drilling could really be causing this. The pads are making contact across the whole surface of the rotor, you can tell by the wear pattern.
Well, if anyone has a thought, please let me know, it would be much appreciated......

 

this is my build thread if more info would help:
https://www.yotatech.com/f191/de6w6i...-lemon-190657/

 

Well, got my new rotors drilled and installed, along with new pads and clip hardware. Re-packed the bearings while I was in there. I also rotated the tires and put air in them, trying to cover everything to see if I can get this vibration thing taken care of. The rear drums had what looked like a dab of grease or something had gotten in the driver side, and the passenger side was adjusted way out. My parking brake froze on the other day, and it may have been stuck more on while driving than I thought, because it smelled. I cleaned everything up with brakleen real good and adjusted everything.
So far, no vibes!!!!!
I will post back if it comes back.