[jeepsterdk]

Hi

Well, I'm trying to assemble the front brakes on my 1978 CJ7. The disc's are new, wheel bearings are new, but still it seems as though the discs are out of alignment. Could this be a faulty disc I received? Or could there be another solution to the problem? Check out the following video for reference

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[whittlecj]

[YT]WoqFnn2bIf4[/YT]

to do you tube just put the video code in {YT} tags - {YT}WoqFnn2bIf4{/YT} Except use [] instead of {}

[whittlecj]

Is the Spindle crooked?

[gmakra]

Maybe a warped rotor?

[whittlecj]

I thought a warped rotor but it seems almost too uniform? Maybe he could put on the other rotor on this side and see if is the same.

[BESRK]

Bearings seated correctly? It looks like the whole hub/rotor is wobbling.

[jeepsterdk]

Originally Posted by whittlecj

Is the Spindle crooked?

I have been thinking about that too. But it wasn't when I pulled the old parts off though

Originally Posted by whittlecj

to do you tube just put the video code in {YT} tags - {YT}WoqFnn2bIf4{/YT} Except use [] instead of {}

Thanks

Maybe a warped rotor?

Maybe, but it's a brand new one

Originally Posted by BESRK

Bearings seated correctly? It looks like the whole hub/rotor is wobbling.

I took the whole part apart again and checked. Yes, they are seated properly

[whittlecj]

I've seen bad rotors new, have you tried the other rotor on this side? Are the spindle nuts fully tightened?

[jeepsterdk]

Originally Posted by whittlecj

I've seen bad rotors new, have you tried the other rotor on this side? Are the spindle nuts fully tightened?

Gonna try to switch rotors. Good idea! Yeah, the nuts are tightened. Damn, I'm getting sick of doing brakes

[HackFabrication]

That's a lot of warp-age for a new rotor. Did you get them turned before you put them on?

Pull the hub/rotor, place it on a known flat surface, and either check it with a dial indicator or use a straight edge/level. If it's warped, take it to a machine shop and have them turned. Tell them what your problem is. They should remove just enough material to get them within 'spec' for run out.

If your spindle is seated in the knuckle, you could also have a bent spindle (merely removing it wouldn't bend it unless you used a 10# sledge).

The 79's used the six-bolt mount plate for the calipers, perhaps that isn't flush with the knuckle/spindle? I'm assuming also, that you cleaned all the mating surfaces up and added a thin coat of anti-seize to them.... Right? Check to see if the caliper bracket is whacked outta shape while you're at it.

Since you've checked the bearings (you did pre-load them...Right?), and assuming you've got the correct bearings installed: You can probably eliminate that as the problem.

[jeepsterdk]

Originally Posted by HackFabrication

The 79's used the six-bolt mount plate for the calipers, perhaps that isn't flush with the knuckle/spindle? I'm assuming also, that you cleaned all the mating surfaces up and added a thin coat of anti-seize to them.... Right? Check to see if the caliper bracket is whacked outta shape while you're at it.

Since you've checked the bearings (you did pre-load them...Right?), and assuming you've got the correct bearings installed: You can probably eliminate that as the problem.

The knucke and spindle was sandblasted, metalized and painted with a very thick paint. So I guess, that the mating surfaces are clean, but actually not 100% plain. If you know what I mean.

Wooops....preload the bearings? Ok, now I need a spankin' for asking this, but how do you do this?

[hh65flyer]

Someone will need to get you the torque setting but essentially you tighten down your wheel bearing to a pre-set torque value with the spindle nut (to seat the bearing). Then back-off the spindle nut (3/4 turn), ensure the rotor spins freely and you are all set.

The torque is probably 25-30 lb/ft but I'm guessing based on working on my B**nco. Good luck!

[foggybottombob]

I've seen this problem when the flat face of the inside of the rotor does not fit up against the hub because the inside of the rotor hits the hub before it seats. I had a friend who had full floating AMC 20 rear axles with disc brakes. It used Ford rotors but we had to grind out the inside of the rotor (the surface that is like a drum brake surface) so that it would seat flat. If you put a dial indicator on that rotor surface and measure the furthese from the hub distance less the closest to the hub distance you will get a number that is called runout. I would guess that you have over 100 thousandths runout at this point. Your rotor runout should be more like 5 thousandths.

[whittlecj]

Jeepsterdk -What ended up being the problem?

[jeepsterdk]

Originally Posted by whittlecj

Jeepsterdk -What ended up being the problem?

Sorry, here's the thing: The lug nuts weren't properly seated in the hub. I used some wheel nuts to get the lug's seated and the problem is gone. Hope you understand...