Front wheel bearing replaced

Hello, So I finally did something a little more than oil changes and replacing sway bar bushings. I replaced the front right wheel bearing. I'll be doing the other one this weekend. The reason I decided to do this is due to a road noise that didn't not go away after getting new tires. When I bought the car, the axles were rebuilt, so I figured the noise is either the front diff or a bearing issue. After completing the job, it seems that the road noise may be down a bit, but it is still definitely there. Btw, the old bearing seemed to turn ok just before I removed the hub. If you are thinking of performing this job, I do have a couple of comments that might be helpful. For one, the B90 sir tools "BMW" set will do this job just fine on front. Didn't try rear bearing yet. I won't go into details unless someone has a question, but it worked great. Second, be careful pressing the hub back in. I managed to bend one of the three lips on the front of the hub. I found out when the wheel would not go flush against the rotor. Luckily a large c-clamp was able to bend it enough to get everything together ok. Third, I popped both ball joints. The ball joint for the lower control arm is a little hard to get access to. I have some good ball joint pullers, but it was still a hassle, but can be done. Last, make sure you freeze your new bearing before trying to press it. I tried 4 times trying to get the bearing to go in straight only to find out it was slightly crooked. I am sure it would've been even harder to perform if bearing was room temp. I didn't bother trying to heat of the carrier. Finally, I have a question with something that didn't go well. I snapped two of the four 13mm bolts that hold the front plate over the wheel bearing housing. I sprayed them down with pb blaster ect and tried to be gentle but it seems like maybe the old bearing was putting some pressure on them which made them very hard to turn. The questions is, can I safely run with just the top two bolts installed. I have a new hub nut and it is cranked down to roughly 340 ft\lbs. In my mind, it seems that the front plate may protect from water and dirt a little and maybe help prevent the bearing from creaping out of the carrier. But honestly, if the axle nut is doing it's job, not sure how that bearing is going anywhere. I'll come back and post if replacing the other front bearing helps with the excessive road noise. thanks.

Hello, Replaced the front left wheel bearing tonight. Very relieved once I got the bearing out I could feel the grinding in the inner race as I turned it. Sure enough, after a test drive my car is back to relatively quite. Too bad I didn't replace left bearing first. Even after doing this job once, it still took me all of four hours to do it again. It's not a hard job, but it is a little involved.

Excellent description of the work, thanks!

I did both my front wheel bearings back in March. The only difference was I made my own puller frame and used the guts of a standard bearing puller set (about $90) as I couldn't see spending upwards of $500 for what would probably be a one time use tool (SIR wheel bearing puller). As you said, overall it was an easy job. The devil was in the details - freezing the new bearings over night and carefully taking apart the wheel carrier so as not to break any of the bolts that hold the backing plate etc... As for running without the two broken bolts - Of course you "can", but I would expect to hear some rattling every time you hit a bump. My recommendation would be to try to get the broken bolts out and put it back together correctly. I don't think the backing plate adds much in the way of structural strength (ie. holding the bearing in the carrier, but it probably does keep water and dust/dirt out of the face of the bearing. I just hate to see shoddy work done on such a nice machine. If worse comes to worst, and you can't get the broken bolts out or you mess up, you can always pick up a used (good) carrier for around $100 - $150... Good Luck

You can see the new bearing inserted. You can also see how I managed to snap the two lower retainer bolts. I did this on both sides. I may have been able to save them if I let them sit in pb blaster over night. Thanks, I am glad after 8 hours of wheel bearing war with my car, it was in fact a wheel bearing and not something with the diff or the axles.

Thanks dporto, I was thinking the same. I've seen the carrier's on ebay. I did get the two top bolts nice and snug and it definitely bothers me that I know they are not "right". I am the type of person who takes my wheels off just to look at stuff like axle boots, brakes, things that u can't see with the car on the ground and wheels on. I also go back and check wheel lug torques two times after a few days each time I take the wheels off. In this case, I will be looking at these carriers making sure nothing is moving around. Of course, removing the hub will mostly likely destroy the new bearings, so I may let this ride for awhile. I am super happy at the moment that my front differential is not the source of road noise. I also didn't mention that I bought new tires before I got the bearings. The fronts were a different brand than the rears and they were 4 years old. The rear tires were only a few months old. I had heard that sometimes old tires that still show good tread depth can get loud. Too bad, I am pretty sure those old tires were just fine. haha

It looks like you should be able to drill those with a really small drill bit and work up to where you can get a decent sized easy out in there (you don't want to break off an ez out in there...). You might also try warming the carrier a bit (I'd use a heat gun, not a torch) as it might help get the PB's in there... Good luck again

Quotes source post: 13610138

+1 And to add to the warnings, ez outs do snap, and sometimes do so with little warning. This isn't a lot of fun anyway, and it's even less fun getting the grinder out going after what's now a broken bolt with a broken ezout.

For anyone wanting a detailed video diy on 996 wheel bearing r&r : Part 2 of 3 Change Porsche front bearings and brake pads - YouTube

I guess I'll see how long my wheel bearings last missing two retainer bolts. My guess is that they will probably last about the same as they would with all four. No point in trying to back out those bolts now as that will just ruin the new bearings I have. For safety, I'll be frequently checking that they are fully seated. Once they go bad (if they go bad), I'll get some new bolts and plan on extracting them when I do my next wheel bearing adventure. The amount of force it takes to press a bearing is making me think that they are not going to budge. I do have the retainer in place, it is just held by two bolts instead of four bolts.

Only 2 of 4 retaining bolts is risky imho. And the broken ones are adjacent at the bottom! Before the redo the job, suggest 1. watching the video above. 2. invest in some Kroil =Kano Products -even better than PB Blaster but it needs time and repeated applications to work well. 3. Use heat to help remove the bearing 4. freeze the replacement before fitting. 5. rent or buy a bearing puller kit and take the time to buy the best size back-up washers if necessary. No hammering required nor advisable.The trick is the Kroil(oil that Kreeps), keeping the bearing square in the housing and pushing+pulling the bearing to allow the Kroil to 'search; it's way between the bearing and the housing. 6. Consider using some sealant on the outside of the bearing to reduce rust and make the next job easier. 7. Get a list of 'while you are in there' jobs from others here ? 8. To remove the broken ez-out and bolts , research cobalt drill bits, left hand drill bits. Replace with s/s bolts of the correct grade and thread.Use sealant to prevent rusting of the non-s/s parts. Agreed, A2 is not as strong as the Class 8,8 (??) you are replacing but 4 x A2 s/s bolts are probably better than two rusty 8.8. !

Good stuff Schnell, I have the B90 BMW kit and it just happens to do very nicely on the front 996 bearings. Actually my whole wheel bearing replacement experience was very smooth minus snapping those two lower retainer bolts.(13mm). I did notice that the retainer had some sealant from factory. I doubt these bearings were ever replaced in first 47k miles of PO. I pretty much like to look for reasons to jack my car up and check things out. So I'll be doing that in the name of safety, as I don't want to lose a bearing. If these bearings wear prematurely, I'll be making a list and getting needed tools to "backout" those lower retaining bolts. This car isn't seeing the track anytime soon, and I am pretty much communting on the highway every day 28 miles each way. I do enjoy the on ramp acceleration and off ramp corners at 20 over the posted speed. Under those conditions, these pressed bearings just don't pop out. They might creap a half mm at a time at most. Still sucks that it is what it is. On the bright side, my car is liquid smooth as the left front bearing was seriously bad. You can feel it grinding as you turn it by hand.

Hello, Thought I would add the following data point that will probably not surprise anyone. Before I changed my front wheel bearings, I was checking the temp of my front rotor hats/hubs when I would pull into my work parking garage. The ride to work is mostly high way with very little brake use. I noted that the temp was very hot to touch. Nothing crazy, no burning smell etc. This was true for both wheels. After changing the front right bearing, I still had the loud road noise. Then I changed the front left bearing and all was good in the world (very quiet ride). I also immediately could feel the grinding in my hand when I got the bad bearing out. I never went back and tested the temp of the hubs after getting off the highway until today. Wow, both hubs were not even warm. The lesson here, is that the front right bearing was not making any major noise but it was still getting hot. It's possible it was making a little noise but the very bad front left bearing was just masking it. So if you think a bearing is the reason for your road noise, drive around at higher speeds, try to not do any excessive braking and check the temps on the hubs. If bearing is good, chances are it won't be warm at all.

When you dismantled the old bearings, were they devoid of grease? I ask because there is a chicken/egg issue about wear causes heat causes loss of grease vs,loss of grease causes wear causes heat. Great diagnostic technique using a heat sensor !No dirty hands required.Thanks for sharing. For $20-20% discount coupon you have a diagnostic tool! http://www.harborfreight.com/infrare...ter-93984.html

How many miles were on your car? My 996 TT has 52k miles and I also have some excessive road noise I think.