idosubaru Posted June 28, 2012 Share Posted June 28, 2012 When pressing the hub into the knuckle - how do you know when it's fully seated? It seems as if you could "press it in too far"? Got my first wheel bearing job finished today for my 02 OBW daily driver. Thanks for all the help from USMB folks. Link to comment Share on other sites More sharing options...
porcupine73 Posted June 28, 2012 Share Posted June 28, 2012 That's a good question. The info I could find said 2.0mm +/- .3mm I think it said, in an Endwrench article. I took that to mean the base of the hub should be that far inside the inner bearing. So I used a depth gauge and kept inserting and removing the HF tool to pull it in bit by bit until I got to that point. It seems though like it was a bit too deep but I'm not sure. It definitely seems to be installed deeper now than it was, just based on where the outer seal contacts the hub. But maybe it had moved out for some reason from axle jobs or something else in the past. Link to comment Share on other sites More sharing options...
unibrook Posted June 28, 2012 Share Posted June 28, 2012 My notes say take a very good precise measurement of how deep seated the hub is supposed to be ... before you remove it from the old bearing. Link to comment Share on other sites More sharing options...
CNY_Dave Posted June 28, 2012 Share Posted June 28, 2012 Having scrutinized the cutaway when doing mine, the inner race of the outboard bearing must fetch up against a ledge or something, so if you get it wrong it would be pulled into place when torquing the axle nut, no? Anyone have a pic of a hub free and clear? Link to comment Share on other sites More sharing options...
CNY_Dave Posted June 28, 2012 Share Posted June 28, 2012 Although this pic makes it look like the race does not bottom against the larger part of the hub? Then how the heck is the preload actually set? This was on a '97 http://forums.nasioc.com/forums/showthread.php?t=832596 Link to comment Share on other sites More sharing options...
CNY_Dave Posted June 28, 2012 Share Posted June 28, 2012 (edited) Maybe this explains it- the part of the race that 'grips' the hub then flares out a bit, and that part fetches up against the wide part of the hub. http://imageshack.us/photo/my-images/87/dsc04785s.jpg imageshack.us/f/87/dsc04785s.jpg from http://legacygt.com/forums/showthread.php/front-wheel-bearing-diy-walkthrough-86994.html?p=3240125 Edited June 28, 2012 by CNY_Dave Link to comment Share on other sites More sharing options...
CNY_Dave Posted June 28, 2012 Share Posted June 28, 2012 (edited) This shows what I mean even though it's for a bimmer, and shows ball bearings not rollers. For the preload to be set, the outboard inner race "1b" must contact the lip on the hub, and the inboard inner race "1a" gets pressed against it by the axle itself, until the inner races touch. If you don't drive the outboard inner race "1b" all the way to the lip where the hub widens, it'll happen when you tighten the axle nut, assuming the race slides on the hub before you reach full torque on the axle nut. So I believe the correct answer to 'how far' is 'till it won't go no more'. Edited June 28, 2012 by CNY_Dave Link to comment Share on other sites More sharing options...
porcupine73 Posted June 28, 2012 Share Posted June 28, 2012 Hm...nice diagram. That makes it look like it would not be possible to install the hub too far. I did notice that when I got to about 2.0mm difference, it really did not seem like it was going to move much further than that because the torque on the tool was really increasing fast. That also makes it look like even if the hub wasn't fully seated, that when the axle nut is tightened it would seat it the rest of the way, provided the torque on the axle nut is enough to move the hub in the rest of the way. Link to comment Share on other sites More sharing options...
idosubaru Posted June 28, 2012 Author Share Posted June 28, 2012 mine seems like it is set in "too far"..a tiny amount of course - since i always reuse axle nuts i took note that the nut did not return to the same position it was in, it was 180 degrees off so not even close and obviously a bit different seating of the hub probably. i felt like it went in a little more than necessary...but who knows i can't really tell. the Subaru hubs do not have a defined ridge that that diagram above shows. i think the hub has a taper to it where it rides against the seal. the only bad part about having it installed too far is that the hub, being used, isn't perfectly clean metal, so it may wear the seal quicker? Link to comment Share on other sites More sharing options...
Olnick Posted June 28, 2012 Share Posted June 28, 2012 Thanks for the excellent diagram CNY_Dave. At last I can visualize how all the parts--hub, bearings, knuckle--fit together! Yes, a picture really is worth a thousand words. Link to comment Share on other sites More sharing options...
porcupine73 Posted June 28, 2012 Share Posted June 28, 2012 That's exactly what I was thinking, that with the seal lip riding on the rusty part part of the hub is not going to be nice for it. I did see some people saying that when replacing the wheel bearing, don't just go with the torque spec in the book, to really lay on it and make sure everything is seated nicely, then check it again after a driving a short distance. Link to comment Share on other sites More sharing options...
CNY_Dave Posted June 28, 2012 Share Posted June 28, 2012 (edited) Here's a pic from the manual I colorized. It shows the pressing operation partway through. There are no instructions on how far to press the parts together, and the only way the pressing operation will stop is if a) ST2 hits the hub (green) when the orange race is flush with the hub or the bearing race (purple) bottoms on the flaring part of the hub. Now, if the hub were to bottom against ST2 then there would be no preload on the bearings because ST2 is just a stand-in for the axle, so it stands to reason yuo keep on pressing until you achieve (. The oil seal is colored red. Edited June 28, 2012 by CNY_Dave Link to comment Share on other sites More sharing options...
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