Hi all,

I have worked on many cars before, mostly VW, american and japanese, rebuilding engines, transmissions the works. When I bought my Mercedes I thought, how much different can that be (the last Mercedes I owned was a 1973 220D). I also thought that my old Acura was pretty bad in how much room there was for servicing but had to find that the C280 is eve worse. Additionally the use all these inverse torx (what is the real name of them?) bolts and nuts.

Anyway I have a couple of simple questions if you could answer them that'd be greatly appreciated:

How does one loosen the accessory belt on a 2000 C280? I looked at all of the pulleys but did not see the chance for any of them to move and thus provide tension to the belt.
Afterwards, what is the size of the Allen wrench needed to remove the bolt from the crankshaft pulley (harmonic balancer)? (any special techniques for the removal of this bolt?)

My check engine light indicates that my front O2 sensors are shot. I can see that removing the rear sensors would be relatively easy. How difficult is it to remove the front ones? What everything needs to come off before I have enough space for the removal? What is a good source for a new (and not ridiculously expensive) O2 sensor?

And finally, the bushing in the right lower swing arm (where the camber adjustment is usually done) is cracked/broken. Is this a bushing that can be replaced (a new one pressed in) or do I have to get a new swing arm? What is a good source for parts like that?

Thanks,

Greg