vwtoys

I hope you had ordered the right part?
[ Not Shown ] REAR SUSPENSION / REAR SUSPENSION / SUSPENSION COMPONENTS / HUB & BEARING
hub & bearing Q5

MSRP Core ? Online Price
$362.17 $0.00 $269.45

It says it's for the rear?

MP4.2+6.0

Not sure if it will be hub plus bearing, or just bearing. I tried to get the combo part for my RS5 brake project in the rear (which needs the RS5 hub to fit RS5 rotors), but found in at least the RS5 scenario you can't get the combined unit.

The Audi dealer OE version may have the center hub bolt and the four trisquare ones. The trisquare ones will probably have the green coating like most any Audi suspension bolt, which they describe as single use; I have always figured the green coating is their version of Lock-Tite and hence their single use guideline. Net, if you find yourself re-using the triquare bolts, make sure to use Lock-Tite on them--as Imentioned I had a dealer installed one back out on my C5.

ELEVENS

I'd be REALLY p!ssed if a rear bearing shows up but that's not going to happen:

[ 2 ] FRONT SUSPENSION / FRONT SUSPENSION / SUSPENSION COMPONENTS / FRONT WHEEL BEARING
front wheel bearing Q5
Includes: Front Hub.
MSRP Core Online Price
$362.17 $0.00 $269.45



Thanks again 4+6 for the single-use hardware caution. I'll goop them up good with loktite blue. Oddly, the parts diagram doesn't show retaining bolts. That makes me wonder if maybe the hub slides over a splined axle shaft and is held on with a big-**** nut?

http://genuineaudiparts.com/parts/20...iagram=F202030

MP4.2+6.0

The standard current Audi bearing/hub design is the bearing shell bolts from the inside of the steering knuckle--where the outer CV joint pushes into the hub center area. The hub is pressed onto the sealed bearing at the center of the shell and is through bolted to the splined CV axle. Some Audi CV center bolts have a hex bolt end where you use a conventional metric socket and others use a 17mm allen wrench socket--typically ½" drive stuff. That bolt is nominally a "stretch" bolt I think, but it's so large I have my doubts. More below.

The art work there from genuineaudiparts (or the same as found with audiusaparts) is frankly lousy in this case. That picture of the hub area is the type found way back on the C3 though C4 era (Audi 5000/100, early A6 and probably through about B5--Audi 80's and 90's) when they used huge circlips to locate a round sealed bearing pressed into a welded up steel steering knuckle. Those were usually a trip to the machine shop to get both out and in, and there were no bearing related bolts. Once things turned aluminum on most of the suspension, they got to the bolt in bearing shell type approach, eliminating both the separate steering knuckle press fit and the circlips. Here's a better Q5 diagram for what is hopefully your model: http://www.partscats.info/audi/en/?i...ent_id=1735929 If you are getting part "23," it looks like it includes the bearing shell bolts (24). Same diagram with (retail) pricing from the jimellisaudiparts site: http://www.jimellisaudiparts.com/sho...category=21739. They don't show a price for part "23" or even the bearing; seems like it is smushed in with the steering knuckle (19) in some convoluted way, but not very relevant most likely given your order is about to arrive and probably was confirmed by VIN anyway. As an FYI, Jim Ellis are the only online dealer I know of which uses quasi true EKTA diagrams--apparently the license is really pricy. But GAP or audiusaparts have the better parts pricing usually.

FWIW as you will find on the center CV bolt, the torque is extremely high, second probably only to a center crank bolt on the motor, if even that. I typically use a good (like 5') length of large diameter pipe or my floor jack handle slipped over a long/sturdy ½" breaker bar. With the right meaty air wrench you might break it loose, but the torque instructions are such that you really need to put it back on by hand--200Nm (148 ft. lbs. I think) PLUS 180 degrees. Hence the need for a huge lever arm. By 180 degrees you will literally be standing and maybe even jumping on the long lever arm (BTDT), so be sure your breaker bar is up to it and you are braced in case the bar breaks at the swivel joint. BTDT too, leading to a trip to Sears with the usual sheepish "I don't know why but the Craftsman wrench just let go one day..."

Good luck w/ it!

ELEVENS

4.2+6 - Once again thank you for the useful info. I'm guessing you're an engineer by trade based upon your mechanical knowledge and thoroughness of your posts. You're a true asset to the community. Thanks again for the help and insight.

It looks as though I'm well covered with parts as the attached photo will testify. Getting the big bolt loose shouldn't be too bad as I have a very heavy duty air driver and pressure to drive it. Seriously thpugh... torque + 180 degrees? YOWSER! Even with a jackstand under the breaker bar's head and standing on my puny 2' "cheater bar", I'm not so sure.

-bill

MP4.2+6.0

... back to both C and B 1's. Thanks!

The parts look exactly as I expected. Actually for all the bolts and hub included price not too bad, though in practice the new hub is unneeded normally. Avoids any question of damaging the bearing while pressing it on, which I managed to do once.

Yes, seriously on the torque. See the 2011-2012 quick reference spec book. BTDT. It takes a 4-6 foot lever arm and full body weight standing on it. You need to crack it loose with the car on the ground, parking brake locked, and block behind the wheel in question. As I mentioned, jack handle end is a candidate for the lever arm, though a bit short. I've done it w/ 1½"+ galv. pipe too. Also need to tighten securely first w/ no weight yet on bearing--like to the initial torque setting--and then do the ½-turn lever arm balancing act back on the ground.

ELEVENS

OK so things are back in one piece and it drives quiet as a mouse again. A few notes:

The axle bolt is Allen 19mm. Nobody in town had a socket except Harbor Freight who had a set of ~ 9 impact quality 1/2" drive Allen sockets for $29. I love Harbor Freight!

I had the bearing knocked out of the hub and pressed back in by a machine shop. I could have done it the hard way but opted for professional help with the heavy lifting (or heavy pressing). $40 well spent.

No suspension components needed to be removed or even loosened.

Regarding torque of the axle bolt: I was surprised that the axle bolt would not come loose with the air hammer driven at 150psi. It came loose with a 1/2" breaker bar and a 2-foot cheater handle rather easily though. Torquing the axle bolt to spec was something else. 200 NM + 180 degrees "stretch" isn't going to happen on my car. I've been wrenching (first professionally then as a shade-tree mechanic) now for 43 years. I think I have a VERY good "feel" for torque. I struggled getting 1/4 turn after the 200NM even using a 5' cheater arm (floor jack handle) - then all hell broke loose. The piece of Craftsman 1/2" drive extension (see pic #2) shot down my driveway about 50 feet! I'm not going to attempt to crank another 1/4 turn - it just doesn't seem right and I don't want to bust that bolt. It's staying where it's at and I don't care what the Audi quick reference guide says (BTW, thanks 4.2+6 for the useful link). As you put it, I'll be sheepishly appearing at Sears in the near future for a replacement haha.

laakness

Your last pic made me cringe!

MP4.2+6.0

And yep, it went just as I thought on the torque--more than an air drive can handle, and literally a tool buster. I use deep impact sockets for stuff like this to avoid extensions; in my case the wrench broke at the swivel point of a ½" breaker bar. I guess this is why they have that ¾" drive stuff I think about as like over the road truck category stuff.

But, as w/ me, a chance to gather up those balky ratchets, worn down screwdriver blades and so on and just bring 'em in to Sears in a batch. "I don't know what happened, it just spontaneously flew apart!"...never mind that the handle may be a bit bent to the eye... On my last trip, they no longer gave you the new ones at the counter, but mailed them to me. The tools went into the discard/rework bin without further review, so I think it was probably an internal loss prevention thing about the replacement.

Good call on the machine shop. Having messed one up the DIY way, its $40 well spent to avoid a possible job re do, or the nagging doubts later.

ELEVENS

Big tools remind me of frequent visits to an abandoned train yard near Marquette, MI. in the mid-70's. Pistons the size of a 5 gal. bucket. Can you imagine wrenching on that scale? And we think we got it bad with a "tiny" 10mm(?) allen bolt!

So did you achieve torque + 1/2 turn? If so, tell the truth... didn't you worry that something other than the tools would break? Even torque + 1/4 turn was waaaay outside my comfort zone