I hit a curb with the rear tire and it bent the axle and I believe it also bent the backing plates. Pretty much everything axle and brake related have been replaced on that side, wheel included. It doesn’t rub anymore but the rotor won’t stay “bolted down” to the hub with the wheel on. It takes some effort but I can pull on the wheel and work it in and out like a slide hammer when the tire is in the air. It does the same when I push and on the rotor from behind. What causes a rotor to not tighten all the way down for a lack of better words? The shaft? The axle tube/housing? Both? I suppose it’s not sitting on flush? The bearing and seal were replaced but I don’t know if the rotor was loose like that prior to replacing them. Replacing them and the backing plates were a last ditch effort to fix the rubbing. I replaced the shaft and rotor first and it fixed it to where the rotor would spin freely but it still rubbed on a spot in rotation. I don’t know if the rotor was “tight” at that point or not, I never tried to pull on it. After replacing the bearing and backing plate it didn’t rub anymore but it still failed the aerosol can gap test, so I knew something was still off. Then I decided to yank on it and I heard metal to metal clanking. Yesterday I put the donut on to see if it would tighten down so I could rule out the wheel being bad but it was the same. What do y’all think? A bad new axle? The axle tube not parallel? I replaced the pan hard bar to see if the old one was bent and it wasn’t. It seems if the axle tube was messed but that it would have shifted making the panhard bolt holes not aligned, but they still were. I’m not sure what to do now.

 

If you could measure that in/out movement and it comes out to be small (like about 1/16-1/8", but more towards 1/16"),that is the normal axle in/out movement of a c-clip axle. Pushing in puts the axle against the torsen 'block' or auburn 'center pin', then pulling out the axle, it stops because of the c-clip hitting the end of the counterbore made for the c-clip.

 

I think the problem more so has to do with the way the rotor is sitting on the hub maybe. It sounds and feels like when you have the lug nuts loose on a wheel and you push and pull it. I’m not entirely sure if it’s the wheel hitting the rotor or if the rotor is hitting the hub though. I guess I could tighten the rotor down w lug nuts w the wheel off and give it a yank to see if the rotor is pulling away. It’s not safe to drive that’s for certain because it didn’t take much effort to loosen the lug nuts when I took the tire off to see if the donut would cinch down any better. Even with them tight I’m able to pull on it (hard) and it clanks around. The other side doesn’t do that. If I remember correctly when I put the rotor on it didn’t slide right on. Like when I stabbed the lugs through holes the bottom stuck our further than the top. I remember that I had to tighten down the lug nuts with the wheel off to get the rotor seated. Maybe the hub/flange on the new shaft be bent/defective? Would the axle housing or axle bearing have any bearing the issues that I’m having? If the axle tube was hanging lower than it should (just an example) would that affect the way the rotor slides on?

 

This makes no sense.
1st the panhard bar holes aligning or not will not tell you if the axle tube is bent or not.
If your backing plates were bent your axle tube flange is bent and probably the tube also. But how does the backing plate get bent by hitting a curb? Thats a rhetorical question because it doesn't unless you bent the absolute **** out of everything.
Do you have a picture of this?

What happens when you tighten the wheel with a torque wrench? Does it still take not much effort to remove the lugs?
Are you sure the lug studs are seated all the way?

If anything other than the axle and rotor is keeping the rotor from tightening to the axle it has nothing to do with anything else unless the axle won't turn after tightening it down.

Try taking the axle out and putting the rotor and wheel on it and torque it down with a torque wrench. Take a straight edge and see if the axle flange is straight.

And just to be clear you replaced the axle, rotor, wheel, backing plate, bearing, seal. Which of the replacement parts were used?

 

The backing plate was the only used part. To the naked eye nothing looks “trashed.” Like there’s no obvious signs of “oh crap, that’s bent.” But it’s on a jack stand the drivers rear tire/wheel sorta kinda looks like it’s pushed in at the bottom if I look at it long enough. As for the panhard, I kind of assumed that if I hit the curb hard enough to bend the axle housing the housing would have at least shifted enough to where the panhard would’ve been bent. Or at least the holes out of alignment some. But they weren’t I replaced it with the car on the ground without having to wrestle the body or the axle. But I guess that might be the case. FWIW I slid into the curb hitting it with the face of the wheel so I assumed the damage would’ve been more of a “shift to the right” vs bending to where it’s hanging lower on one side.
I know that the shaft was bent because I couldn’t turn the rotor past the brake pads by hand. After replacing it it would spin freely but but for about 1/4 of a rotation it would rub the pads a little. After replacing the backing plate it spins free all the way around.
If the rotor and axle bolt to the bare axle then I assume that means the tube is bent? I don’t have a torque wrench, but the lugs nuts tighten down like “normal” and they take a “normal” amount of force to loosen right after they’ve been tightened. When I was messing with it last I tried to take pics of the rotor to see if it was sitting even all the way around. None of them came out real well. Looking at the pics I realized I’d have been better off measuring the studs to see if they were the same length all the way around the rotor, because I don’t believe they are. Some of the studs appear to be sticking out the rotor further than others. So this brings us back to what? Either the new shaft came bent or the tube is f’d?

 

I'm not an auto shop teacher or anything. I'm sure I could figure it out, but I can't figure out how to walk someone through figuring it out.

If the axle tube was bent enough to cause a problem the axle shaft wouldn't feel right going in. It would be tight. If the tube was bent little enough to not be obvious it would just wear the bearing over time.

The reason I ask about a torque wrench and studs is because sometimes new axles and studs won't be seated all the way and tightening with a torque wrench would ensure they are seated and that they are not stretching from being over-torqued.

I can't picture the rear end right now even though I have a car in the garage and backyard. I'd see if a straight edge could be put on various areas of the axle tube.
Also try to measure or at least eyeball the wheels sticking out. Maybe it didn't bend the panhard bar but maybe it bent the mount. You could take a 2x4 and hold it on the wheel and see if theres equal space from the 2x4 to the body on each side.

Take a ruler or tape measure and see if each stud is sticking out of the axle flange the same amount.

 

So, I'm not sure if I completely understand everything that has been checked and exactly what symptoms are still presenting (other than the lug nuts seeming to not hold torque after operation) but my first thought, based on my understanding of the issue and history of the problem, is in agreement with the below:

^ Seems very plausible as a source of the issue here, especially when taking this part into consideration:

Unless I'm missing some key element here, based on the issues which remain, it seems like the possibility of studs not being properly seated is very likely. Whether or not they have now become damaged during the course of operation (due to not being fully seated) is another matter. But initially, the issue could have simply been that they weren't fully seated.

 

If I’m understanding correctly if the lugs weren’t fully seated from the factory and I overtightened the nuts that would/could make them all seat at different lengths for lack of better words resulting in the rotor and wheel not being able to snug down? And the way I can tell if that’s what happened is by measuring the length of the lugs sticking out from the hub? If they are indeed different lengths then maybe hopefully having new lugs pressed in would get me up and running?
I can borrow a torque wrench from work to see how it is when they’re torqued down to specs. But I bet the probability of the wheel still being loose is high huh because they’ve already been tightened down too far? The studs being all different lengths might make some since as to why the rotor doesn’t slide on easy by hand. I have to slide it on the bottom first and the top will barely have enough stud to get the nut on. Then I had to tighten down the lugs all the way in the same manner as you’d tighten a wheel to get it seated. Would a bent tube have any bearing on how the rotor slides on the hub? The axle shaft slides in and out real easy but I have to lift up its all the way in to get the shaft into the diff. If I don’t it hits a “wall.” That normal? I only had one side jacked up if that makes any difference.

 

I have no idea. Borrow a torque wrench and tighten the lug nuts to spec. If they keep going and never tighten they may be stretched from over tightening. And if you keep going they will break. Or if you tried to finger tighten a lug nut all the way down it won't go because the threads are stretched apart.
I would think by now the studs are seated.

What brand axle is it and did it come with stud already installed?

Is the parking brake in the way of you sliding the rotor on?

 

The axle was a Dorman with the studs already installed. It came with another set though for some reason or another. The nuts tighten down down fairly easy if memory serves. I don’t think the threads are messed up and not tightening down all the way. I think it has more to do with how the rotor is sitting on the hub. I should’ve slid right on correct without having to tighten it down in a star pattern with the wheel off to get it on flush? I actually didn’t install the parking brake shoe this last time when I was putting it back together.. So there should be plenty of room. 😂

 

The rotor should slide into place (through all 5 studs) without having to "force" it on by torquing the lug nuts. Something isn't right there.

The axle might have come with extra studs of a different diameter, length, or thread for another application (such as older 7.5"/7.625" rears that used SAE studs rather than metric). But if your factory lug nuts screw properly onto the studs then I don't see how the pre-pressed ones could be wrong.

I'm still bothered by the fact that you state (if I understand correctly) that some studs stick out further from the rotor hat than others. That is not right, something is causing the rotor to not sit properly (thus presumably causing the same problem with the wheel), and the "wobble" that results might be the reason it won't stay tight after operation (assuming stud threads aren't damaged).

Really hard to imagine what might be going on without seeing this in person.

 

Post a pic of the rotor (all the way on) sitting on the hub.

 

Here she is. You can see where the wheel was rubbing from being loose. So one more time, could an ill fitting rotor & when be caused by a bent housing or just a bent axle flange? I guess if the tube was bent I guess the wheel might not go on flush all the way around (more tube sticking out of the center on the top than the bottom or vise versa)resulting in not being able to get the lug nuts tightened down evenly. Or if the tube was bent would it still bolt up normally and it’d just have a toe in or out look about it?
If I jack up the rear on one side and put a level on the tire should it be level or will it be off because it’s jacked up on the one side?
These pics were taken last weekend. I was having trouble holding the phone and measuring tape so I didn’t get any that were all that definitive as far as measurements go.






I think it might be the way I was holding the phone to take the pic that makes it look like it’s leaning that much.

 

Where is that rotor from ? The lug holes look oversize. Axle from India ?

 

^ I agree, something isn't right about how that rotor fits he studs (or stud pattern), almost like it's not the same bolt circle and/or the holes possibly being drilled for a different stud diameter.

Have you checked the bolt pattern to make sure it's a proper 4.75" (120.65mm)? Here's a chart for how to measure, obviously you want the 5-lug version:

 

Remove the rotor and take a pic of the axle, pic of other side of the rotor. Does the rotor from the other side of the car act/look the same ? How does the original rotor look on there ?

Where did you acquire that axle, part number ?
Where did you acquire that rotor, part number ?

 

I'm very surprised you guys never paid attention to stock rotors. They center on the hub so the stud holes don't matter.
This is a GM disc for a brake swap I'm going to do. (probably won't use these rotors just the other parts)





Guess where these Alloy USA axles are made. I don't know but it's not the USA I forgot, I've had these 8 or 9 years now. There are literally a handful (as in 5) of axle manufacturers in the world, especially right now.

 

I agree on the centering on the hub but that pic didn't look right.

 

Be a typical customer, and I don't mean this in a bad way, customers do this all the time.

Put everything back together and find a shop that does tires and brakes, etc.

Go in there and tell them you need that tire balanced because the weight fell off when you were cleaning it, or whatever.
Maybe ask if they can check the brakes while they're at it.

Get a detailed receipt, maybe tell them you're trying to sell it and want the receipt.

This is apparently too much to do with the limited tools you have so make it easy on yourself. If theres a problem and they don't find it they will be liable. Sounds crappy I know but people do this all the time, just ask a mechanic.

 

I also agree about centering on the hub, but since the OP mentioned having to "force" the rotor on with the lug nuts in this post:

...I wonder if the bolt pattern on the replacement axle is a bit off, even if the hub is correct, causing some interference with the studs and preventing a proper fit with proper torque? I don't ever recall having to force a rotor to seat with lug nuts. If it was a drum, then shoe adjustment could be a culprit here but my understanding is that the OP didn't even reinstall the parking brake assembly so there should be no such interference in this case. The rotors should fit without a fight, IMO.