Rear wheel bearing replacement (LONG)

Ok, you guys asked for it. I have had several inquiries as to how my rear wheel bearing replacement went. Here is how I went about it. I'm no expert, wrench or writer and the usual disclaimers apply. Take it for what it's worth.Ok, this may be a lil longwinded but I want to try to get all I can in and allow you to learn from my experience/mistakes.

First off, this is a pretty tough job if you want to do it right without the factory tools to get it apart. Having said that, I'm an idiot and got it all done with the tools we had in the airforce maintenence bay.

Disassembly: Take off the wheel and rear disc. No biggie here, just remember the two phillips head screws that hold on the disc. Take off the axle nut using an impact. If you are using a hand tool you WILL need a long pipe to break that thing free. It took me considerable effort with a big impact. Now, remove the 6 allens or bolts holding the driveshaft in place. The best way to get the bolts out is to again use an impact gun. Then you can keep the car in neutral and spin the shaft to get access to the bolts. There is a sweet spot that will allow you to get a good angle on those bolts using a 3 foot extension. I would highly recommend this method. It would be a hard time laying under there with a hand wrench... possible, but hard time. You would have to loosen with the car in gear, release(neutral) move to a good spot, put in gear, loosen, etc. Next remove the bolt holding the shock on. It is just way easier to get the shaft out with the shock loose. At this point the drive shaft will slide out. Check the joints for wear, you may need to replace those too. Now you will need to pull the old hub out. The preferred method is to have the car high enough to use a large drift and a very large hammer and drive it out from the backside(inside) of the car. This was not working for me. It may work for you and you may get lucky. But keep in mind these Porsches like to see how much their owners can take. You may have to result to other less conventional methods. What wound up working was a heavy slide hammer with a three finger puller deal. NOTE!!! If you do not secure the brake caliper up with safety wire the pounding will cause the brake line to crack adding a few hours to the job making new lines and bleeding breaks. Lesson learned. Also when you have the car apart you may need to change the dust boots on the caliper, the e-brake pads, or the brake pads themselves. I had to replace all of the above. See the part about the cars testing the owners. After much pounding/spraining of the wrist the hub will come out. Expect part of the bearing to come out with it. On all the ones I have done, the inner race has come out with(stuck on) the hub. What that means to you is you will have to have a race splitter available. This tool is two wedged halves that compress together to pull the race far enough away from the hub face to get a puller on there. When I say race, it is not a true race per say but you will know what I mean when you see it. You could probably take the hub down to a shop somewhere to get it off, I dunno. I just would count on it being that way and either have the tool or a place to get it off ready. When you do get the race off, check the surface of the hub. One of mine was all chewed up and the cause of my noise. Take care not to drop, clamp, pound, dork around with the smooth surface of the hub. It is very soft for some reason and it damages much easier than it looks. A new hub is expensive but they can be found at junkyards. Again, just keep in mind your car may be down longer than you expected if you need to go find these parts... again lesson learned. Ok here comes the part where you work smarter rather than harder. Note how many threads are showing on the e-brake cable nut and remove it. You will want to put that nut back on in the same position later. If you plan on adjusting the ebrake before you put the car back together it won’t matter that much. I do suggest you adjust it as many many cars are out. The brake should be snug around 4 to 5 clicks on the handle. You can find adj proceedures in the archives. Take off the 4 bolts holding the outer bearing plate and remove it and the brake assembly. You could actually back these four bolts out before you remove the hub but you can't get them all the way out as they will hit the hub. As the hub slides out you would keep backing the bolts out till they fall out. The plate will then come off with the hub. I did it both ways with no real difference. Anyway, with all that stuff out of the way, it is now time to get the old bearing out. Now you can use as much force as you like here(old bearing) but sometimes it just doesn't want to go. I have used two methods, the second I prefer. Method one is to take the slide hammer and reverse the three claws so that they are facing out. Oh, another note here. The bearing is made up of two inner halves. the front halve will probably have come out with the hub. The back halve will probably be in the bearing or have fallen out the back. If it did fall out, put it back in... you need it to grab onto to pull the bearing out. Again, with the inner halve in the back side of the bearing, put the slide hammer claws through that beat the living crap out of it (pull it towards you). It usually comes out... however I have had one that would not and sprained my wrist, the shop owner's wrist, and broke a guys leg trying to slide hammer it out. This is where I came up with method 2. You will need a large piece of threaded rod with a bolt head on one end or two nuts on one end. The kind used in gear pullers is what I used... it had a bolt head as part of the rod but a piece of threaded rod and two nuts would work as well. Stay with me here It needs to be about two feet long. On the back side you need a nut, washer and a socket that fits on the inner back-side of the bearing. This is the piece you pulled on to get the old bearing out. On the front you will need something larger than the bearing (very large socket) to press against the control arm, a washer and a nut. That will be the hardest part to find. I wound up using a huge cup shaped piece that is used to balance tires. It fits on the aluminum control arm just around the bearing housing. Anyway, the idea is to tighten up the nut, holding of course the bolt head on the threaded rod, thus pulling the bearing towards you. I hope the slide hammer method works for you, but if find yourself stuck, this is the best way out other than a tow to a professional Porsche mech. Heat would probably do wonders here but I have a feeling it would be hard to isolate the housing while not heating the bearing as well. Several cycles of heating and cooling may help break it free. Once you have it out you are in the clear. Just clean everything and put it back together. There are a few tricks that I want to tell you...

Assembly. I don't care what anybody says. If you don't put it together the way I am going to descibe, you put too much stress on the bearing. The advise I got was to press the bearing on the hub and drive the hub in. If you look at the physics involved, you are putting too much stress on the inner bearing and it will pop out the back and just piss you off. I tried this way and it is just dumb. The best way to do it is to take the bearing and tap it in the housing on the control arm. DO NOT hit the inner part of the bearing. Just tap along the outside of the bearing with a pretty stout hammer. 5 pound hand sledge worked for me. Make sure you are putting it in squarely!!! You can and will take off parts of the housing putting it in cock-eyed. As you tap it in the back inner side of the bearing will probably fall out... again, the thing you were using on the old bearing to pull it out. Just make sure as you tap it in you have the area clean and have something down to catch it. It will go right back in but you do not want to get any dirt in there. Just press it back in and put the seal back on. Again, every one I have done has had this happen, no big deal. Once the bearing is flush with the housing, put the break deal and the bearing plate back on with the four bolts. Don't forget to do this! I did once... just once and installed the hub. Holy crap was I mad and I ruined a brand new bearing trying to get the hub off again. Now to press the hub back on. Put the hub into the bearing as square as you can and try to get it to go on just a little. It may or may not go on enough to hold it in place. Put the threaded rod through the hub and place the socket that just fits on the inner race and nut on the backside and a large socket, washer, and nut on the hub side. When I say socket you can use anything, but I have some old large sockets that work best. The socket on the backside should fit just on the inner part of the bearing. You do not want to pull on the outer part or anything else. This stresses the bearing. The front socket doesn't matter so much but a pretty big one that fits on the flat area where the shaft comes through works best. Then use a washer and nut and just tighten the hub on. It will slide right in. MAKE SURE you are on the inner part of the bearing on the back side at all times!!! If the socket slips you will be pressing on the seal... a bad thing. When the hub is installed to the right depth it will get real hard to turn. It will be pretty much flush with the inner part of the bearing on the back side. You will know when it is on. There will be a little play in the hub when it is installed. It goes away when the drive shaft is in. It kinda scared me at first but it was like that on all the ones I have worked on. The only other thing I can think of is be careful when you put the bolts back in the drive shaft. When the car is on a jackstand, the angle is kind of wierd and it is hard to thread a bolt in and keep the mounting surface at the right angle. It is easy to cross thread here. Get one bolt started... usually easiest to get the top one, and get it to within a few threads of tight. That should pull the shaft pretty close to the right angle and allow you to booger it around and get the very next bolt in. Just kinda work your way around. It's only wierd because it's a little opposite of normal practice where you try to get all the bolts in a cross pattern.

This is by far the longest email I have ever written. Sorry, but I wanted you to know what you are getting into before you get the car apart. I do not want you to go hammering things together like I have seen other people advise... it is just not smart. If you can't get hold of a slide hammer or the gear puller/long threaded rod deal, you probably want to have somebody do it. It took me like 5 hours per side. It was pretty tough going. But, I will not let anybody else touch my car. It was worth the satisfaction of doing myself and knowing I did it right... or as right as I could. Good luck, and feel free to get up with me for clarification, or more help. What seems to make sense to me who has seen this, may not make any sense to you. Just tell me I'm an idiot and I will try to make it make more readable and clear.




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rj cilurso
87 911 targa

Excellent, well written posting! I will print this out and keep it with my maintenance manuals!

Kurt V
72 911E

Thanks so much for this description!

You've convinced me not to mess with the rear whell bearings and if they need replacement, take the car to wrench and spend the money!

But I admire your courage and persistence.

- roGER

thanks for the great info, I will be checking into mine this weekend although I think my problem is the front bearing. I am hoping it is a slightly easier procedure as there is no drive shaft to deal with. I to would rather not take my care to the mechanic if not for any reason but $$$.

Great post! BTW, the front wheel bearings are a COMPLETELY differnt animal, and very, very easy for the home mechanic to change. Even the Haynes manual is sufficient for the job!
So, Robfix, if you think its the front, you may be in luck!

thanks Jim
you confimed what I thought. However I hesitate to buy the Haynes manual as I understand it is not that useful for much else. The factory manual is not that clear in this area. Anyone have any other suggestions regading reference material for this procedure? Probally would make a good tech article on this board, hint hint.
Rob

Yes, the fronts are way easier. I was not impressed with the Haynes. I had a few other things to say but I will keep my mouth shut. Anyway, my Bentley's should be here on Fri and I am hoping that it is better.

I recently replaced the rear wheel bearings on my 911SC, and can offer some advice:
Remove the control arms from the car completely, drive out the hubs,and take the control arms to your local machine shop or motor engineers who are equipped with a hydraulic press and suitable mandrills and let them take care of it. This avoids the risk of damage to the new bearing or the control arm and saves a lot of swearing and cursing. The cost? ....£20 ( or $30 for you americans )Money well spent !
Congratulations to everyone at pelicanparts for a great website for Porscheaholics.
Isnt technology wonderful ?

plus the $300 for an alignment

DOH! I should have mentioned to mark the position of the control arm relative to the radius arm with a scribe prior to dismantling. You can then recover the original alignments on reassembly. Although this will not guarantee a perfect set up, I would not recommend anyone "beat the living crap" out of the suspension and expect it to stay in perfect alignment either.

[JohnJL]

cool old-school post. how many others remember posting things 14 years ago when you just wrote in prose. no pictures, no slang, just proper discourse and exchange.

Found this looking how to confirm the rear bearings are adjusted properly.

[rattlsnak]

I just went back and dug up some old ones of mine from late 2000. I had links to pictures and videos on AOL!!

[m110]

Cool post, I wonder if rcilurso is still around.

I was looking through an old email account and have a bunch of the original "porschelists" (predessesor to Rennlist) postings from the mid 90s before it was forum based!