Scary?: Rotors slightly contacting dust shields during hard corner (wheel bearings)

[MRGTX]

My car has stock front spindles/single piston disk brakes.

The rotors (along with the wheel bearings) were replaced ~5k miles ago when I first got my Dart back on the road. A that time, I recall looking up and following some recommendations about adjusting the tension on the wheel bearing nut but I haven't gone back to check them yet. I also remember noticing that the dust shields were a little bit bent. I did my best to tweak them back into shape but I didn't go crazy since (it seemed to me) they merely needed to clear the rotors and be left to do their job and that is how I left them- and they were just barely clearing the rotors, IIRC. I mention this because there is likely less clearance than stock...though I could measure that if it matters.

During moderately hard cornering on left hand turns, I can hear a slight "scratching" sound, seemingly coming from the front right of the car. I am 99.9% sure it is coming from the rotor making slight contact with the metal dust shields.

In all honesty, this has been going on for a long time, not getting noticeably worse or changing. Since installing more handling-related parts, I have been pushing it through corners harder and also paying more attention and suddenly, I feel like this needs to be addressed right away, preferably before a wheel departs the car mid-corner.

My question is this:
How much lateral movement is within spec for healthy wheel bearings?
Is it worth attempting to tighten them up a bit or would you consider this to be an immediate safety concern and replace the inner and outer bearings before driving again?

 

[ACME SS]

Probably the most common mistake people make when adjusting wheel bearings is adjusting them with grease between the rollers and the race. (that and over greasing) It is a good idea to roll the wheels and recheck, and recheck them after a short test drive. This will squirt the grease out that is holding the bearing apart. You want some pre-load on the bearings. Wheel bearings are not too critical but some equipment will actually call for measuring the preload with a torque wrench (rolling resistance) or with a string wrapped around a shaft and connected to a fish scale, so you do not want play is what I'm getting at with bearing designed to take an axial load. I actually assemble bearings with a light oil first and count the number of turns to remove the nut, then I grease and tighten back to that same point. But that is probably a little excessive for most people.

In your case I would probably take it apart, clean the bearings and inspect them. They are probably OK. If so, reuse them, or replace if you are not sure.

I purchased a camper once and the previous owner told me he greased the bearings for me. When I got home (10 miles) I jacked it up and found I had about 1/8" of play.

 

[halifaxhops]

Also sometimes the calipers will not return all the way and if the rotor is a bit loose it hits one pad during turns.

 

[Dana67Dart]

There is a torque spec for the nut IIRC 90 inch pounds. Check your FSM

That being said, what I have always done:

1. grease things up just the way the FAM shows
2. assemble
3. spin the tire/wheel while tightening the nut, this insures that there is no excessive grease between the roller and the cup
4. go a tad over finger tight, then back it off till there is a slight amount of noticable play
5. see how the nut and keeper line up
6. tighten a tad or loosen a tad to align
7. then cotter pin.

This procedure has worked well for every car I have owned over 50 years.


The wheel, rotor and caliper will be mostly moving together, slight movement between the rotor and caliper due to flex and the bearings, which is normal and helps move the pad away from the rotor so it is not always dragging.

I suspect the dust shield as you pointed out, I had the same on my KH front discs.

I was able to move it away from the rotor on the car with the wheel attached. If it has 1/2 inch clearance it should not touch

ALL THAT BEING SAID...

if you are really loading up the suspension with hard cornering, it can't hurt to pull and inspect things

 

[65wgn440]

More than likely just the bent shield causing the contact, but before you start taking things apart, you need to check wheel bearing play, I would think. Jack up each front wheel and manually check side to side or up down play. Should have no play. If you jack up under lower control arm, as far outward as possible, you can check entire front suspension at the same time, with help of pry bar under tire. If you do have any play, you will have to determine if it is bearings or ball joints/ bushings/ steering components as cause.

 

[Dana67Dart]

If you do have any play, you will have to determine if it is bearings or ball joints/ bushings/ steering components as cause

I thought my bearings were really loose, turns out it's the entire 55 year old suspension, bearings were set perfect.

To prove this snug up the bearings so there is noticable drag on the bearing and give it the movement tests. If you feel / hear clunking it suspension. Then reset bearings and and plan for a suspension rebuild.

 

[toolmanmike]

You can bend the shields a bit. They don't need to be that close to the rotor. I always spin the rotor or drum while tightening the bearing, back off the nut and do it all again at least a couple times. If the cotter key doesn't line up, tighten to the next notch. The wheel bearings aren't supposed to be preloaded but not loose enough to clunk when you pull in and out on the drum or rotor. Done it that way for better than a half century without 1 bearing failure or issue.

 

[hemi71x]

You have a contact issue with the dust shield, simple as that.
Bend, adjust, as necessary.
Problem over.

 

[72bluNblu]

So the FSM says...

This is basically the way I've always done it. Grease and install the bearings, put the disk and hub on the spindle with the outer bearing. Tighten the nut until I can feel drag on the disk when I spin it, then back it off until it spins freely again. From there I tighten again and usually go a bit more than "finger tight", I shoot for zero end play on the rotor which is a little tighter than "finger tight" for me but should still be basically 0 preload, which I check by spinning the rotor and making sure I don't feel any resistance.

For me, if there's no noise or interference when you're going straight down the road but there is under hard cornering your wheel bearings are probably too loose still. Unless that dust shield is just a sliver off of the rotor at rest. I'd definitely inspect the dust shield and rotor to see exactly how close that is, maybe bend it back off the rotor a bit more, and recheck the wheel bearings.

For what it's worth, I don't run dust shields at all. Many cars never came with them. I find they're much better at trapping dust, rocks, and heat against the rotor than they are at keeping anything off of the rotor the rest of the time.

 

[Daniel S C]

How close splash shield is has nothing to do with any movement - check the bearings and the hub to be sure the race is tight in the hub, if you need help with final tension ask someone or take it to a shop , you'll get it right you don't want any movement , if you look at the back plates there would be a mark from the rotor if it was touching ! I've had customers install bearings and not seat the race completely and after driving it will work it's way to fully seated leaving too much free play - don't want to ruin parts/ have it spread and chew up the spindle or worse have it come apart / if this has been going on for a long time and your worrying about it now ? DON'T do that waiting game anymore OK, take a good look and hope you have a good outcome