Thomas Stahel

iTrader: (1)

Hello

I've read in my manual about adjusting wheel bearings. And there it says, that I have to loosen the nut until either hole in the spindle lines up with a slot in the nut. And then... "Not more than 1/2 flat."

Can anyone "translate" this for me in a more understandable "language" ;-) I'm Swiss and I didn't findt a useful translation for "flat" in this context.

Oh and by the way... what if the ideal position of the nut doesn't line up with the hole in the spindle? Is it better to have a bit more play or a bit less? Normally while the bearing is in use, the play will increase, won't it?

Thanks,
Thomas

Tuned Performance

iTrader: (92)

Flat refers to the flat section on the nuts outer surface. Don't over tighten the wheel bearing. the easiest way to set the preload is spin the rotor and snug down the nut to alittle mor than zero pro load. back it off do it again. Then set the nut to zero pro load it that can't be obtained with the pin lining up and is preloaded tight set the preload on the loose setting.

Thomas Stahel

iTrader: (1)

Hi

So 1/2 flat would then mean?

In my manual it says, tighten to 16Nm while turning the wheel (is the direction important, by the way?). Then back off until just loose and re-tighten by hand until it's snug. And so on...

What do you mean by "zero pro load"?

By the way... I have a dial indicator so I will be able to measure the play.

Tuned Performance

iTrader: (92)

half a flat means half the distance of one side of the nut. The torque is not important you are just seating the bearing in the race. You will not need a dial indicator just make sure when you are done the is not a tight load on the bearings you are just seating the bearing then lining up the hole in the spindle leaving no preload on the bearing or if there is it will be very very little.

Thomas Stahel

iTrader: (1)

Okay, but why is there a torque given in the manual? I mean, if I torque it too much to seat the bearings... it's no good... I'm not a mechanic so I guess I don't have the right "feeling" in my hands ;-) I always like it more to measure everything.

What I was always thinking about... can it be dangerous if there is little too much or little too few play? Or would it become obvious when driving like by noises or so...? What I'm also a bit afraid of is driving the races into the rotor. I actually bought a bearing driver set by Lisle but I read that when hammering the races in it's more likely to damage them than when pressing the races in. Is there a possibility to see whether the races have been damaged somehow through the driving-process? And again: what's the safety risk if I drive with a race that has a flaw? Would I notice it while driving?

Thanks a lot for your help!
Thomas

Tuned Performance

iTrader: (92)

same same

Damon

Forget "torque" when it comes to wheel bearings. Turn the nut down BY HAND until it bottoms, spin the rotor to make sure it's seated. Back it off until it's JUST A TINY BIT LOOSE FROM FULLY SEATED. Repeat the process untill you feel comfortable you've got it. You're done. Stick the cotter pin through it and drive it.

If you have it down so tight it's got no play whatsoever, you'll know it. When you drive it around you'll smell burning grease and brake pad material after not too many miles. Yes, the rotor gets THAT hot if the bearing is to tight it's got actual torque pressing against it.

I set them so I can just barely feel a little "clunk" from the bearing if you wiggle the rotor back and forth. No movement you will ever see by eye, just enough you can barely feel it with your hands.

If you get the idea this is a "feel" thing that takes some experience to know when you've nailed it, you're right. Wheel bearings, like any other bearing, need just a TEENY TINY bit of clearance to allow the lubrication (grease, in this case) to get in between the working parts and do it's job, preventing metal-on-metal contact.

Thomas Stahel

iTrader: (1)

So, now it's done (at least the right-hand bearing, the one which seemed loose to me). The bearing had quite a lot of play. And the outer one didn't look good either. On the metal between the "rollers?" it looked scratched and the material seemed to have been grinded away. The inner one seemed to be okay.

So it was quite hard to get the races out using punches... there's so little material to tap on. But finally they both got out.

After mounting the rotors back to the spindle, I turned the nut down and used, anyway, a torque wrench set to about 16 Nm. I turned the rotor and torqued slowly to 16 Nm. Loosened it and did that procedur about 4 times. Then I turned it tight with my hand. But doing that, the rotor had still quite a lot of play. So I had to tighten the nut another - say good 1/4 - turn, now there is no play that I could feel and the hole in the spindle is lined up with the nut. But I'm a bit confused. Normally you could do the screwdriver test. If the play is good, the washer behind the nut should move with little pressure of a screwdriver. That worked for me when I hand-tightened it, but there was too much play. And also the manual says to hand-tighten the nut and then loosen it until you reach the spindle hole

I didn't finish everything because it was dark and raining, so I just put the grease plug on and installed the caliper. Tomorrow or so I will finish. So then I can again try to adjust the play better and also try out my dial indicator. I mean... if I have one I can also use it ;-)

Thanks,
Thomas

BTW: In the manual it says that you torque the nut with a wheel on the rotor. Does it make any difference?

BTW2: Could you tell me realistically, if I had made a mistake hammering the new races in, so that they are for example wedged, not completely in or otherwise damaged (so that I couldn't see it by eye) or the inside of the rotor has some flaws, could it become dangerous? I mean, could the bearing get jammed suddenly after some 100 kilometres' driving without any signs before like a noise or so?

MoJoe

iTrader: (5)

A hex nut has 6 sides. Each flat is 60* rotated from the next. 1/2 flat would be about 30*.

Thomas Stahel

iTrader: (1)

Okay, but nonetheless I had to tighten the nut quite a bit to not have any play. The next opening in the nut (loosening it) gave me too much play.
I'm going to measure the end play with my dial indicator.

Who can tell me something about the risk when driving with a race that hasn't been set all the way down or has been wedged etc.? Will I notice it early enough by a sound or so...?

Greez
Thomas

Damon

This just sounds weird. Do you have the right bearings for your application (or the correct rotor for that matter)? Everything is designed to basically "flat stack" when you tighten down the spindle nut- all the bearing surfaces come into contact at the same time. There is no tight or loose, they're either touching (no play in the rotor on the spindle) or loose (clunking back and forth slightly). There is no "adjustment range" on the nut except for a small fraction of a turn on the spindle nut between too loose and too tight (i.e. "half a flat")

I'm having a hard time imagining what's going on in your situation. It's just not making any sense to me.

Thomas Stahel

iTrader: (1)

Well, I'm pretty sure that the bearings were correct. I bought them at Rockauto and double-checked with Amazon. They also looked right compared to the old ones. The rotor is the old one.

So you're saying that strongly hand-tightening the nut should get me to no play already? In videos on youtube with the same kind of rotor they also tighten a bit more to fit the holes. Maybe I didn't pretighten the bearing enough or I gave it too much torque? Could any of these mistakes lead to too much play when hand-tightening it? Or if the races weren't completely in or wedged, could that cause such a problem? I think that everything should actually be assembled correctly. And I don't think that I put in the bearings in the wrong direction (guess it wouldn't even fit if I tried to put the bearing into the rotor with the wrong side facing up / down)?

So I guess it's going to be Tuesday when I'll be able to look at it again.

Thanks,
Thomas

naf

iTrader: (7)

Check for play in the bearings by grasping the rotor at the top and bottom and pull it in/out. You should feel a definite clunk when the nut is loose.

Tighten the nut JUST until there is no play in the rotor (fully seated), then back it off just enough to insert the cotter pin. The final setting will be slightly loose from fully seated.

The nut and spindle have several places for the cotter pin to be inserted. By design, when you loosen the nut to insert the cotter pin, it will not need to be loosened more than '1/2 of flat' to be able to insert the pin...if one of the holes in the spindle is not lined up with a slot in the nut, it is behind one of the 'flats'.

Thomas Stahel

iTrader: (1)

Thanks @Naf, I'll try it again.

So you wrote I should tighten the nut to seat the bearings JUST until there is no play in the rotor. So if I already overtigthened it a bit with my first attempt (I didn't put more torque than about 16 Nm) do I have to take off the rotor from the spindle and put it back on and reseat the bearings or can I "losen" the bearings by just loosening the nut a bit and move the rotor on the spindle?
Actually my "problem" is not, that there is too much or too little play (at least not too much... for the too little play, I'll try out my dial indicator). My "problem" or uncertainty is that I did everything like the manual says... seated the bearings with 16Nm, loosened the nut just a bit, hand-tightened it (and I tried to tigthen it as much as I can with my fingers) and still there was too much play. So I had to tighten it with the socket a bit more. But in the manual it says, from hand-tight I should even have to loosen the nut for a correct setting. And with the "not-loose"-setting I also can't move the washer quite easily with a screwdriver which should be possible.

Could it have something to do with my spindle... or at least with the thread? Maybe that there is dirt on it? Cause when I tigehtend the nut by hand (from the very beginning of the spindle), it didn't move that easily.

And on the other hand, I did this job for the first time. So I can't judge whether the races are really correctly seated in the rotor. The outer one went in quite easily. The inner one got wedged when I started hammering but using more force it finally also went in. I have to say that I used a bearing race driver. What I also noticed were two small, round dents / "dimples" (next to each other, only about half a millimeter deep) inside the rotor. I'm not sure whether these resulted from hammering out the old races with the punch. They were quite at the end (one end) of the rotor "tube". People who do this job many times might see a lot of such small flaws and can judge what is normal or uncritical or not. But I can't really estimate which "flaws" could cause which problem like the one that I have now tightening the nut to the correct play (which isn't even sure to be a problem yet). I mean, in the worst case, one race could have gotten a tiny and invisible crack when I hammered it in, and I don't know what that could lead to when driving and the race really cracks. Or am I overanxious?

Thanks,
Thomas

naf

iTrader: (7)

You're overanxious. Just loosen it until it's good, with no play. You actually want to overtighten them first to ensure the bearings are seated so you're fine.

The washer under the castle nut should not spin. It has a groove in it that locks it onto the spindle. If this washer is the one you're referring to.

If the rotor spun freely and smoothly throughout its rotation, the races are likely fine.

If you're still worried, you can check them after a short drive by feeling the hub for excessive heat. They should feel to be about the same temperature. Overtightening can cause overheating, as can a bad bearing or such.

You can also jack the wheel up and check for play by pulling/pushing at the top and bottom of the wheel. Check this immediately after installing them and then check it again after a few hundred miles. Should be the same.

Another symptom of a bad bearing is a hum, or buzz that you can hear/feel while driving that will change pitch as you turn slightly.

Thomas Stahel

iTrader: (1)

Okay, I know the sound. That's why I changed the bearing. I wonder if it's gone now. We'll see.

What I'm afraid of is that the race might have gotten an invisible crack and suddenly it really cracks completely and the wheel gets jammed. I don't think that a slightly cracked race can be noticed in a rotor spinning not smooth or freely...? And there also won't be any noise because the complete brake of the race could come suddenly...?

Yes, I mean the washer under the nut. I didn't mean that you should be able to spin it. It's just a test for the correct play using a screwdriver. Some say, that you should be able to move / shift the washer (not turn) with very little force by a screwdriver. They say it has to be "moving suckingly"... don't know the English expression.

Greez
Thomas

Thomas Stahel

iTrader: (1)

Now, I looked at it again. The dial indicator is really not a big help as the top of the spindle isn't flat, so it's hard to put the indicator on exactly.

Well, the problem is still the same. I even took off the rotor and put it on again, then tightened the nut to about 20 Nm while spinning the rotor. Then loosend it and tightened it with my fingers. Even if I use all my force, I think there's still some play. So from where I hand-tightened it, I would have to tighten the nut even more to get no play to line up with a hole in the spindle.

I really don't know what to do. I called the shop where I once made a "work experience" for some months. They will look at it on Thursday. Unfortunately I can't stay to watch them. But tomorrow I'll have another look myself, I have one day off. Today was a bit stressful. Do you think driving three kilometres with a too loose or too tight bearing can already damage it? Should I drive slowly and make stops after some 100 metres to prevent overheating?

As for the play. If I grasp the rotor at 12 and 6 o'clock, I can wiggle it and there's also a sound. I mean, if I pull at it straight with both hands, there is "no play". But wiggling back and forth is possible. But maybe I misunderstand "play", I don't know. But on the left wheel I actually can't feel any "play" like the "play" I feel on the right side where I replaced the bearing. Maybe I didn't hammer the races in completely anyway? I mean, that could actually be the only reason for my "problem"...? There aren't that many causes, I guess... the bearing/rotor-system is not that complex.

Maybe I'll make a short video tomorrow for you to judge. It's quite annoying if one tries to fix something and, in the end, no one can really tell you, what you've maybe done wrong

Thanks for all your support
Thomas

RBob

iTrader: (1)

Thomas, hopefully I can help. There is supposed to be a little bit of bearing end play when setting the spindle nut. This is required, as the bearings heat up from driving the car they expand and the end play is taken up (reduced).

You can use the dial indicator to set the end play of the bearings. That is how I do it. The GM spec from the '92 FSM is .001" to .005" (inch) of end play. It doesn't matter that the end of the spindle isn't flat. Just stick the magnetic base of the dial indicator on it so that it doesn't move.

Zero the indicator on the face of the rotor.

Grasp the rotor and push it in (evenly on each side). Note the dial indicator position.

Now pull the rotor toward you and note the dial indicator reading. Only need to use reasonable force on the rotor. Too much and the rotor will defect.

The difference is the end play. I usually go for the middle range in the .002" to .0025" range. I have found (over many years) that this is the best way to set the front wheel bearing end play.

Converting to metric:

.002" = .0508 mm
.0025" = .0635 mm

RBob.

Thomas Stahel

iTrader: (1)

Thanks RBob

I did pull at the rotor yet. You say it will defect if one pulls too much. "will defect"... what does that mean? Does that mean I can damage the rotor? I mean, I wiggled and pulled already for quite a while. How will it show that the rotor has been damaged?

Actually the question is whether it has to work as described in the manual. Hand-snugging then loosening it. If it has to work like this, something is wrong here, because if I do so I always get a too lose rotor. It surely is right to have a tiny bit of end-play, but as I read, you shouldn't be able to notice it when wiggling...?

Thomas

MoJoe

iTrader: (5)

"Defect" was a typo. RBob meant "deflect". If you pull too hard on the rotor, the rotor will move too much, and you will measure a higher clearance than is really there. As a result, you will then overtighten, and have not enough clearance for the bearings.

Thomas Stahel

iTrader: (1)

Hi

I've finished now, but I couldn't really use the dial indicator as you explained because the magnet has too little power to hold on to the spindle. As I'll show my repair to a shop tomorrow, I've just tightened it so that I barely couldn't wiggle the rotor. Actually, in the whole thread noone told me whether with a correct adjustment you can wiggle the rotor or not...?

I drove some 100 metres and what I could smell was something burning but that was how it smelled also before I replaced the bearing. I have a loss of oil at the motor oil seal and as the car wasn't driven for some days, it could have been the oil that was burning somewhere. I put my hand onto the grease cap and onto the washer and it just felt warm.

I hope the shop will be able to check this thorougly.

Today I made a video showing the wiggling but as I'm sick, I don't know whether I'll post it today.

Thomas

Thomas Stahel

iTrader: (1)

Okay, so I uploaded the video. It's not that good quality but you can hear the "play" or the "clunk" when I wiggle the rotor at one side. That was when I loosened the nut, tightened it by hand and backed it off to the next hole in the castle nut. In the end I tightened it more to the next hole which still gave me a very little clunk. We'll see what the shop says tomorrow. Might my spindle be defective?

Thomas

http://www.youtube.com/watch?v=pR5gC...ature=youtu.be

Thomas Stahel

iTrader: (1)

This morning I drove to the shop and actually there's something wrong. When I do a bit sharper turns the wheel "jumps"... you can feel it kind of rubbing and I didn't really feel comfortable.

Now, I guess if it wasn't a mistake with reassembling (hammering in the new races --> maybe one is wedged and not completely in) it could only be a defective spindle because I was driving with the humming sound for too long. I mean, it was almost for half a year...

If I need a new spindle, I saw that Rockauto doesn't have one in its catalog. Are there still new ones to buy or do I have to buy a used one?

Thanks,
Thomas

stealtht/a

iTrader: (1)

It does sound like the spindle is damaged, you can't replace just the spindle, it's part of the whole steering knuckle. Haven't seen any stock new ones available, just drop spindles and such. Prob have to get it from a salvage yard or other used parts source.

naf

iTrader: (7)

Some 'jumping' (actually wheel scrub) with the wheel during sharp low speed turns is normal. It's a design issue of the steering system where parking lot manners were sacrificed for performance. You may not have noticed it before when the old bearings had failed and the play alleviated the scrub.

Worn strut mounts can also cause some funky steering issues in sharp turns. Take the plastic cover off and inspect the bearing and rubber isolator inside of each. You can also have someone turn the wheel while you inspect each. Look for evidence of tears and lateral movement of the strut rod.

If it drives fine and has good steering your spindle is likely fine. Excessive bearing wear on the spindle would have been visible.

Thomas Stahel

iTrader: (1)

Well, I know this kind of "jumping" from earlier. It has always been jumping a little bit, but just a little bit. But even when I drove about 15km/h and pressed the brake (when I didn't really turn) the wheel jumped or even slipped. Well there was a gully cover under it but I thought putting in a new bearing should make things better not worse. So, as I can't really judge it and the brake maybe also needs a bit of brake-in-time, I'll have to rely on the shop's report.

So I guess you've listened to the youtube video. You could hear the clunk that was still there when I tightened the nut to the next hole (although it was less loud). Would you say that this is just normal?

As for the spindle... the weather was not that good and I didn't really look at the spindle after cleaning it. And as I'm inexperienced I might have overseen a visible abnormality. Should have made some photographs...

Thomas

Thomas Stahel

iTrader: (1)

Today I got my Camaro from the shop.

As it seems, the 16Nm were far too little force. The mechanic said, he always tightens without a torque wrench and quite firm. So as he did so, after loosening the nut and hand-tightening it to the point where the washer could be slightly moved by the use of a screwdriver, there wasn't any play anymore as I experienced when I only seated the bearings with 16Nm. The mechanic thought that maybe the bearing races could have been driven not a 100% in the rotor and by tightening the nut a lot more than 16Nm, they got correctly seated for the last tenths of millimeters.

So I hope everything is alright now. At least the humming noise in turns is gone.

Thomas

Thomas Stahel

iTrader: (1)

Well, the smell of something burned hasn't stopped yet. And after a ride down a steep road (though in the 2nd gear) left my hubs (yes, both!) so hot that you would burn yourself touching it. But maybe the smell is anyway coming from burning oil leaking through a seal as there is quite an amount on my parking-lot when the car stands for a day or so.

Thomas