2002 S8 Front Axle Replacement
 

So I was thinking about doing control arms this summer as car's at 75k miles. I was inspecting today, and noticed a lot of grease flung from inner cv boot on passenger side. As far as I know, replacement axles are fairly inexpensive, so I'd probably just replace it.

However, I've never done one. I'll browse my Bentley, but if anyone has seen a write up or has a few tips, I'd be grateful. I.e. list of tools and sizes of bolts (inners appear to be triple square and then there's the big nut on outside of course.

Does anything have to come off, or can these be done in place? A good source for replacement? Should I do the drivers side at the same time?

Thanks in advance and happy Friday!

UPDATE: So I posted procedure from Bentley below. Can anyone confirm I need to loosen control arms to get axles out? If this is the case, I'll replace axles when I do the arms. From control arm procedure on Audipages, that pinch bolt can be a b!+ch!

Audi > A8/S8 > 1997 - 2003
Suspension, Wheels, Steering
40 - Front suspensionDrive axle, removing and installing Removing
Remove hubcap. For light alloy wheels pull off center cap (use pulling hook in vehicle tool kit).
Remove center hex bolt for drive axle.
WARNING!


To reduce the risk of accident, vehicle must be standing on its wheels when loosening and tightening center hex bolt for drive axle.
Raise vehicle
Remove wheel.
Remove hex bolt for drive axle (2nd mechanic operates brakes).
Remove drive axle from transmission drive flange.
1 - Hex socket head bolts
Remove wiring for ABS wheel speed sensor from bracket at brake caliper (arrow).
Pull ABS speed sensor slightly out of wheel bearing housing.
Loosen nut -1-, remove hex bolt and pull both control arms -2- upward.
CAUTION!


Do not use a chisel or similar tool to widen the slots in the wheel bearing housing.
Note:
Do not loosen bolts -3- and -4-, otherwise the alignment must be checked.
Swing wheel bearing housing to side in direction of arrow.
Remove drive axle.
Installing:
Insert drive axle in wheel bearing housing and bolt to transmission drive flange.
Insert both upper control arms and tighten nuts to 40 Nm (30 ft lb).
Press control arms as far as possible toward wheel bearing housing when tightening.
Bolt drive axle to transmission drive flange.
Tightening torques:
M8 = 40 Nm (30 ft lb)
M10 = 70 Nm (52 ft lb)
Press ABS wheel speed sensor into wheel bearing housing to stop and insert wire in bracket at brake caliper.
Tighten hex bolt to 190 Nm (140 ft lb) (2nd mechanic operates brakes).
Install wheel.
Tighten drive shaft hex bolt.
WARNING!


To reduce the risk of accident, vehicle must be standing on its wheels when loosening and tightening center hex bolt for drive axle.
Turn the M16 hex bolt: 190 Nm (140 ft lb) plus additional 180 ° turn

Replacing the entire drive axle just because of a leak is a TERRIBLE IDEA.

At only 75K miles, you have the best equipment made on the car now...complete aftermarket axles cost a fraction of the price of OEM for a reason.

NO ONE makes a replacement anywhere near the beefy quality of the originals, including "Raxles" (best? aftermarket brand, but still NOT OEM) who others will no doubt chime in and recommend...NOT if all you have is a leak, NOT a failed component.

Don't throw away (or trade in) a perfect $650-700 OEM axle that has not failed...these will go 1/2 million miles when properly maintained.

The inner CV's (triple roller) are notorious for leaking a little grease from the inner clamp seal, even when it's not ripped yet. The inner joint uses a different type grease (amber) than the outer joints...plus the inner joint "accordions" in and out, adding some possible pumping action to any leak. As long as the boot is NOT ripped the joint is not contaminated and go forever with part of the grease leaked out.

To pull the shafts for CV boot service, I've always used the Bentley method. Some (northern cars especially) have trouble with the pinch bolt on top, so use an alternate method unbolting a lower control arm instead...I'm not familiar with the alternate method. The only thing I add to the Bentley method is removing the inner cast aluminum heat shield above the inner joint.

Outer joint service >>>

http://forums.quattroworld.com/a8/msgs/45872.phtml

Thanks Sam, good to know. I'm all for repair of OEM, and it appears there are no tears (turns out drivers side is leaking as well). I kept feeling for one, but got bummed out as I wasn't even looking at axles to begin with and called it a day.

So I guess I just need inner boot kits. Any recommendations on a supplier for these? OEM as well?

A couple more questions: I don't own a spline drive socket set, so may just purchase the size needed for the 6 bolts. What size are these? Also, what size is the hex for the axle bolt?

Most important when ordering inner boot kits is get a kit that comes with the new metal end cap...like PartsGeek.com GKN inner kit. It is possible to pull an inner boot all the way over from the outer end, IF the outer CV joint is off the axle...otherwise that end cap has to be pried off (ruined in the process) to access the snap ring that holds the tripod roller on the shaft. When the tripod is off, the outer casing (race) of the joint slides right off the shaft to give easy access for a new boot.

The inner cv bolts come off with a #2305 (10mm) triple square (12 point) socket.

The axle bolt comes off with a 17mm allen wrench socket and/or key. Breaking it loose can usually be done with a big breaker bar. I put mine back on with a 17mm socket on a torque wrench to put the 1st 140 ft lbs on it...I then use a 17mm allen key with a long tube to put the full 180 degree extra tightening turn on it (I mark it with a sharpie first).

Boot kits ordered (including end caps). The inners were $12/kit, so I just ordered outers as well as I'll have the axles out anyways. Your well documented outer cv tutorial inspired me to just service all 4 joints. Plus, I already own a railroad spike so the outer service was a no-brainer :D

So parts are due to arrive tomorrow, and I've acquired all the tools necessary to dismantle and reassemble.

What did you find to be the best way to get all the old grease out of the joints? Soak the joints in a bucket of degreaser of some sort? It seams that only using brake cleaner would take a long while. I've read the Audipages procedure that recommends mineral spirits, but then warns against leaving it on too long.

http://www.audipages.com/Tech_Articl...toverhaul.html

I usually degrease with mineral spirits (that's what's in my parts washer) and blow dry with compressed air. The pump in the washer does most of the work. A parts brush and bucket of mineral spirits will also work. Glad Sam inspired you.

Well got one side rebuilt. I'll have to admit that I hated this job. It fought me the entire way.

The 2nd easiest part was removing the axle bolt. The easiest of all was the pinch bolt, which from reading the control arm procedure I thought would be the hardest! From this point on, I got a bit frustrated, to say the least.

The front control arm popped right out. The rear didn't want to budge. Tap tap tap...nothing. Pull up with all my might...nothing. Every part of me wanted to pry the gap open with a large screwdriver, but I knew I'd damage the aluminum. So I tried gently tapping the joint out from the bottom...nothing. I finally came up with wedging a small piece of wood in the pinch point. FINALLY popped out. Hard part over, right? Ha, not even close.

Undid the (what felt like way more than 45ft-lb) 6 axle bolts. I had no helper so it was a balancing act of wedging a breaker bar between lug nuts with my knees to keep the shaft still while awkwardly freeing the bolts.

Ok, axle finally loose on both ends and steering knuckle free to move out of way for removal. Easy, right? Not a chance.

I'm convinced the heat shield MUST be removed (as suggested to do by silverd2) to get the axle shaft out. I got the 2 two outer bolts out just fine. The 3rd (center) bolt is way way up there. Did I have a stubby socketed 6mm hex? I didn't. Got slightly presentable and made the trek to Home Depot. They were out. Off to another HD and they had one. Ok now it's 4 hours later and the axle is still inches from where it started.

Got the heat shield removed and the axle was easily removed at this point. Now time for the greasy fiddly bits. Easy, right? Probably would have felt easier, but when you've been sweating for 4 hours it never seems that way. Locked it into the vise and used the railroad spike/sledge drift method. Finally, something went as planned. Cut off the outer boot and dunked the joint in paint thinner. Cleaned with brake cleaner and air dried. Rebuilt and regreased outer joint, and covered it up to reinstall after I quickly did the inner joint. Inner joint simple, right? Sort of.

The end cap has no place on earth to pry from. The lip is recessed from the housing and there is NO room to get anything worthwhile in. I called my indy mechanic and he's like "just pry it off, gingerly but persistently." It wasn't gonna happen that way. What to do now? Cut it off? Will I be able to press a new cap in? What if I just leave the cap on? I left it on and cleaned the roller bearings from the other side. With the boot off you can be very thorough here. I used a very thin nylon brush to break up some of the old grease that was between the rollers and hadn't moved in 10 years. Dunk dunk brush brush and all was well. I didn't want it to be in thinner long so I alternated between thinner and brake cleaner. There is a rubber o-ring under the end cap. Does brake cleaner hurt rubber? I don't think it does if not left on for long. I rinsed thoroughly with water after and quickly blew air through to dry everything.

OK finally ready for reassembly. The inner boot is rather difficult to install from the outer end. I had to use some plastic trim sticks to get it over the shaft and into position, but it will make it eventually. Greased and clamped the inner boot. One side done. Ok, just have to slip a boot on and tap on the outer, right? Ugh, I almost lost it here. I got everything lined up, boot on and shaft in vise, and gave the axle nut a whack. Ball bearing goes flying across the garage! WTF! I nearly chucked the axle into the street and gave up.

The weight of the grease in the inner race had allowed the assembly to drift downward which is why this happened. Ok, no big deal. Go find the bearing and reclean, regrease and reinsert. I couldn't get the outer joint to go on with a mallet nor any light blow hammer I owned. I ended up taking it out of the vise and used a piece of wood and baby sledge to get it back on. Ok just clamps left. Easy, right? I think you know where this is going.

The clamp that came with the GKN inner kit was simply too small. It wouldn't engage the tab on the clamp. I carefully respreads the old clamp and ended up getting an extra notch to engage before I crimped it. I feel good about the tension here. I'll keep an eye on it and probably replace at next oil change.

Finally finished. Best shower and beer I've had in a long time. I don't wish to share the exact time I spent on this job, but I think I could have done the timing belt faster (I'm assuming...haven't done the belt yet but it's on the list). However, with what I learned, the other side should (knock on wood) go much smoother!

got the cv axles rebuilt,now wheel bearings start to make noise,new tires 3000 miles ago,got them rebalanced and rotated and still makes rumbling noise...vorsprung durch constant repairs money sucking black hole audi s8