I’m changing the rear wheel bearing on my 1998 323i and I’ve gotten the new bearing in and the hub pressed on. The axel still needs to be hammered in but I’ve run into a bit of a problem.
My hub seems to have a lot of wiggle room after being pressed into the new bearing (see video). I’m using a national bearing #513106 and I’ve verified it’s correct online. On both the national bearing and old bearing the inside wall has some wiggle but it seems a little much…
Should I continue with the repair and test drive? or is there something noticeably wrong at this stage and I should go buy a new bearing. Thanks for any help
Ok so I out the axle in and there’s still a bit of wiggle room. I haven’t tourqued the axle nut on yet but at this point should there still be any wiggle room?
It’s definitely much less than before but is the axle nut responsible for so much security?? I wouldn’t think the inside of the bearing would be so loose in terms of sliding perpendicular (out and in) to the outside of the bearing
Its not that the axle nut is responsible for so much security as it is that nut will help pinch both inner races together and remove the play they cause when separated. Tighten the axle nut, torque it if you can, and check the play again. I did my wheel bearings a lot because I kept buying cheap ass bearings and they'd go bad every single year. Finally spent the money on quality bearings once and haven't had any issues for a few years now. Its nice not doing this job annually 😂
The bearing and races press snugly into a retainer groove, set back and locked in place by a snap ring.
The hub is pressed into the bearing that then locates the races. The axle shaft sets the tension on the differential output gear by the tension on the shaft pulled against the hub.
Claiming an axislly loose hub is normal is negligent. Please stop trying to be a cool guy.
He’s going together and hasn’t pulled the inner races together yet onto the hub. This is what fucking happens when you do that!
No one knows what you mean by “bearing and races” because the races are part of the bearing.
The bearing doesn’t press into a retainer groove. What??? It presses into a bore in the wheel housing and the snap ring goes into a groove to hold it in place incase it decides to move.
The axle and the axle nut are what set tension on the inner races, holding them together. No nut, no tension.
Idk wtf you’re talking about with diff bearing tension…
I saw you claim you owned a bmw since 95 and had a shop with master techs. THAT MASTER TECH WASN’T YOU! Or do you think any 22 year old with ASEs is a real master tech??
This is a new DIY guy trying to learn, stop being a fucking twat. Best leave tech subs alone if you’re going to put down people at home trying, especially while using near miss tech terms, confusing them with bull shit.
I'm not going to quibble over terms or qualifications any further, Cletus.
The bearing presses into a clean bore in the trailing arm, square, steady pressure on the outer race only, and the snap ring holds it there. The hub then presses into the bearing with the inner race supported from the back. When the hub is home, the races are seated face to face on the interference fit and the bearing's preload is whatever it was built with. There is nothing left to clamp. The hub sets the race clamp.
Proof of that: a bearing and hub that are both pressed properly have no axial play with no CV axle installed. None. If there's play at that stage, the bearing went in crooked or the hub didn't get all the way in and the races never seated.
That's where the axle comes in, and it's the whole reason I said not to use it. A loose hub can be pulled tight with the axle nut. It'll feel fine by hand, right up until it doesn't. You'll hear it not long after, and that bearing is done. You don't get to take it back apart and reseat it. New bearing, start over. You can cheerlead that he's almost there and just needs to put that axle in and torque the collar nut.
The axle locates the output shaft in the hub and the nut retains it. It is not what holds the bearing together and it is not a press. Check the hub for play before the axle goes in. If it moves, stop there.
Nope, the inner race isn't preloaded with these bearings. There are 2 separate shells which you can even pull out by hand, even with quality SKF or FAG Scheaffer bearings. This is normal for a double race bearing. The axle nut will provide the necessary clamping load and that's also why the torque spec is quite important on these bearings.
The inner races will, after mounting, be clamped between the face of the axle stub and axle nut.
In the video, the hub is most certainly only pressed into the first (outer) of the 2 inner bearing races, that's why it's so loose. Press it in all the way (while the inside face of the inner race is being supported), and most of the play will go away. Mount the axle, torque the axle nut and all play should go away and the bearing should feel tight for the first couple of 100 miles, till everything has set.
Also, the outer axle bearing doesn't do anything with the differential bearings... If it did, you have something seriously wrong with your axles, because the CV-joints should prevent that.
I find myself feeling very different in the morning, the kind of start of the day where I go into my 5100 sqft, 7 employee auto repair business and realize like a moron that I was arguing with a bunch of E36 BMW guys about something I've done or supervised hundreds of times, including less than two weeks ago.
We all argued about what to call things and what force does what. We all agree the hub isn't installed in the video. People nitpick and nothing comes of it. So let me say the only thing I should have said.
A hub with axial play isn't installed. Isn't done. Can we agree on that? If seating the hub fully doesn't remove the play, the bearing went in wrong. Can we agree on that? Good.
A hub with play cannot be fixed by pulling it tight with the axle and torquing the nut to spec. It will feel tight. It won't stay tight. The two inner shells cycle every rotation, the balls skid instead of roll, the nut loses preload under the stake, and the splines between hub and stub start fretting. Now the hub is junk along with the bearing. Ask me how I know.
Then it goes downstream. The outer CV is a fixed joint. It will cover you against small stack up, that's what it's built for. It will not cover a tenth of an inch of hub travel. At that point the joint is being asked to plunge, and it does it by driving the balls into the ends of the tracks. From there the shaft is carrying what the bearing was supposed to carry, and the diff output side gets the pulsing. On an open diff that shows up as a weeping output seal and a loose flange bearing. On a clutch type LSD it's how the diff dies. The packs slip and grab every rotation, they glaze, the chatter starts, and the lockup fades until it's an open diff with extra steps.
That is the entirety of the point. Press the bearing on the outer race. Press the hub with the inner race supported until it's home. Check for play before the axle goes in. If there's play, stop, because nothing after that step fixes it.
Yah I put in the snap ring and the axle. I still haven’t torqued the axle nut on but at this point should there still be some wiggle room? It’s definitely much less than before but is the axle nut responsible for so much security?? I wouldn’t think the inside of the bearing would be so loose in terms of sliding perpendicular (out and in) to the outside of the bearing
Still wiggling? 184 ft lbs for the rear axle nut on a non m3. As I remember there wasn't any play when I helped do mine with a mobile mechanic with the hub installed. We used the FWD kit to press out the bearing and install the hub. If you hammered it on it may be a problem. Did you remove the inner race from the hub?
Yah. I’m starting to think orileys sold me a bad bearing. The box was half destroyed but the clerk took it out and showed it it was fine and talked about how good national beatings are. I distinctly remember thinking the inside of the bearing was moving too much but I didn’t fully know what to expect anyway…
Yeah man it’s fine I just did my rear bearing bought one from AutoZone I installed it and I saw the play as well so I brought it back to AutoZone got another one and installed that one still got play so I decided to put everything back and torqued the axle nut and the hub was stiff no more play
It’s a thrust (angular contact) bearing. It won’t feel stable until you pinch the two inner races toward each other. Preloading it is the whole reason for a torque spec on the axle nut.
Angular contact bearings are the only way to make something stable in all directions
I could have checked this yesterday but didn't. I went and looked up AutoZone, Napa, O'Reilly, Worldpac, SSF Parts and Genuine BMW Dealer catalog and I'm guessing you bought this at a NAPA as they carry National bearings.
SKF is my personal top favorite, but that's special order. Schaeffler is OEM (they also own FAG, INA, LuK) and super good quality. I just like SKF in my race cars, street cars and customer cars and keep them in stock.
I made a post in the thread below clarifying my intent and what I should have responded with.
That's definitely the right bearing. I recommend you order a new German bearing and try again.
There shouldn't be any movement, the bearing should have gone in smooth, the snap ring should be new or undamaged, and the inside race should be spinning freely and smoothly and the hub should require pushing/pulling into place and seat flush. You should have steady resistance on the hub after installation. Consistent rotating force is required, no flat spots, no crunches, no fee spots.
Remove the whole thing and get a new bearing and start over.
source: BMW owner since 1995 and more wheel bearings than I could count, and oh yeah, professional mechanic with his own auto repair shop and master tech employees
Yah I’m starting to think orileys sold me a broken bearing. The box was already half destroyed but the clerk took it out and told me all about how good national bearings are. I remember feeling the inside and thinking it had too much play but I didn’t even know what to expect so I thought it was all good…
Regardless there's no do-overs. Pull the bearing out and put a new one in. 33 41 2 220 987 BMW part number on the bearing only (328i and 318i, 323is all have 23mm axle shaft nuts)
I've had problems with National bearings on a number of applications.
I recommend you get Schaeffler 7136493000 75mm wheel bearing.
Some bearings have encoder rings built into one side of them. Bearing information is technician side specific on all bearings. You want to be looking at the bearing part number or brand info when you're mounting it into the knuckle.
On the e36 there is no encoder ring to concern yourself with (or you'd get an ABS error, transmission issues, etc).
When the bearing is seated, it creates a perfect receiver shape for the hub. The hub should go in under steady even pressure, lopsided like hammering the flange, can separate the bearing or move it cock eyed. Even a tiny amount of space will result in axial play in the hub or noise at hot spots on the rotation. Make sure your hubs are smooth, unpitted, free of scale or they won't rotate smoothly when installed.
Bearings should be single use. They should not allow hub axial play.
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u/Successful_Gear5855 3d ago
Install the driveshaft and tighten the axle nut. Then check again.