I finally got a round tuit and started messing with my E420 brake upgrade. Someone on the MBshop forum tried this and said the bigger front rotor hit the lower control arm, d'oh. But Rick (2phast) had no problems with his 190E, so I figured it was worth a gamble. Anyway, they don't fit - yet. With the stock font rotors, there is about 3mm air gap to the splash shield, and another 3mm from the back side of the shield to the ball joint / LCA (lower control arm). The problem is, the bigger front rotors are 6mm deeper! Translation - no air gap, no fittee. If the shield was removed entirely, the rotor would probably be at most 1mm from the LCA, way too close.

There are two solutions. The obvious method is to use the correct, late model LCA designed for the bigger rotors. The bad part is that the BJ is not replaceable, it's welded in place. If the BJ goes bad, you have to buy another control arm. It also means buying used ones is risky. They're $200-225 each for OEM/aftermarket (Febi).

Another option is to swap the 500E/R129 hub, knuckle, and steering arm. This will push the hub (and wheel, and tire) outward approx 5mm, which could cause clearance problems if you are using wide wheels/tires. But it will allow the brakes to fit.

The 278mm rears are fine - they will bolt up with zero problems once the splash shield is cut or replaced. Some new photos of the parts & current brakes have been uploaded to my website, and there is also a spreadsheet there with all the part numbers for the brake parts, LCA's, etc etc...

http://www.W124performance.com/images/W124_brakes/


Best regards,