Some of you remember I had a post recently about front wheels vibration while I was just touching the brake pedal. I've replaced the brake discs and it fixed the issue. But my bushings are cracked. So far they are holding the road very well... Anyway, few pictures:
Maybe I have stupid question, but before doing it I'd like to understand how people do that. I've seen post recently about it by BMW750. I remember he had some issues doing that. So, I'd like to ask few questions. I have Audi A8, 2007, 4.2 FSI BVJ, sport suspension
1. What type of bushing you prefer? I think going with original, but some prefer the aftermarket blue with no metal ring outside. Somehow I think the physics would be different on those without ring. Eventually they would be able to rotate inside of the arm. I think. Just want the opinion.
2. I was looking at the space there and could not figure out the proper process to replace those bushings. Also I'm afraid to touch the air suspension. Traditionally I would dump the full assembly down and work with it. But looking at the air suspension it has few pipes going there and I'm not sure if they could be disconnected. So, any advice really appreciated.
3. What is the proper technique to compress them in the control arms at home? I can see how polymer bushing would be easier to compress them in rather than original with metal ring around it.
Use OEM bushings. There are two types (prices). I would suggest more expensive ones (~$35) since they are dedicated to S8. Polyurethane ones are better but they create noise and have to be lubricated every now and than.
Nothing special in replacing them. You have to disconnect both ends of the links, push, or cut out the old bushings and press new ones in. It can bi done in vise but press would be better. Only problem are inside ends of rear links. Bolt doesn't have enough room to be pooled out, but you can just force it by unscrewing it until it is out. Put it back from the other side.
It's not a fun job, per se, but it's not horrible. It is MUCH easier if you loosen the top mount to the strut and use a pry bar to pull the whole assembly down a bit to get to the bolts (obviously a help here is handy).
I used PowerFlex urethane bushings, and the improvement in handling is fantastic. You do have to grease them periodically to control noise, but they'll last forever.
The PowerFlex bushings are dramatically better than the stock rubber, BUT every month you have to raise the car to Lift mode and spray some lubricant on them (takes a total of less than 2 minutes). If someone comes up with a better method for lubricating please let me know (I was thinking about getting a long piece of tubing and squirting grease back in to the bushing)
Last edited by 05SilverA8; 09-11-2013 at 09:59 AM.
But the challenge is the air suspension. Somehow I need to disconnect it if I'll follow the steps from the link above. That's what I'm afraid to touch.
Also, I understood the BMW750 never fully dropped the struds So, I'm trying to figure out the best method for myself how to do that. I'm not even sure I have to do it right away as I do not experience any issues so far. That is definitely something to do in the future.
You do not have to do it right now. They will look worst when it becomes urgent. Even than your wheels are not going to fall of.
Forget that link. That's if you want to replace all of bushings, but on our cars lower ones have way longer life. To replace the upper ones you just follow what I said in my previous post and if you do not fell like forcing anything you drop the top mount a bit, as bmwm750 suggested, to take that bolt out.
The completely other way to deal w/ the bolts is...
...to cut them--the ones that have clearance issues when removing that is. That's what I did on the 2000 C5/A6 4.2 with basically the same links. The new kit I used came with all the nuts and bolts needed, so I had new ones on hand anyway. I did it with a demo/reciprocating saw, but the A8 may have somewhat less room. In that case a cut off wheel would do it; if you are comfortable w/ those kinds of tools that is. The bolts are hardened, so w/ the demo saw it took a hacksaw/metal type blade.
As you already know or can see in the other replies, replacing them is easy since you just put them in the other way--like the factory should have if they thought through service and maintenance.