Hella 355104322 Rear Brake Rotor 290mm | Mercedes-Benz

The Hella 355104322 is a rear brake rotor built for a long run of rear-wheel-drive Mercedes-Benz cars from the mid-1990s through 2011. It's a 290mm solid, one-piece disc, the kind that lives on the rear axle of the W210 E-Class, the W203 C-Class, the CLK coupes and cabrios, and the R171 SLK. If your Benz is due for rear brakes and you'd rather fit an OE-quality replacement than pay the dealer counter, this is the disc that does the job.

Let's talk about how it's built. The casting is gray cast iron with a zinc coating over the whole thing, the hat, the edges, the vanes, and the swept faces. That coating matters more than most people think. Bare cast iron starts flashing orange with surface rust within days of sitting, and on a Mercedes the exposed hat and outer edge sit right there behind an open wheel where you see them. The zinc finish keeps those non-friction areas looking clean and slows the corrosion that road salt loves to start. The swept faces wear the coating off in the first few stops, which is exactly what's supposed to happen.

It's a solid disc, not vented, at 10mm nominal thickness. The machine limit is 8.3mm, so there's very little meat to give. On a thin solid rear rotor like this we almost always tell folks to just replace rather than resurface. You won't get a real second life out of it, and a warped skim job isn't worth the labor. The rest of the numbers: 290mm outside diameter, 55.40mm overall height from the hub face to the disc, and a 67mm center bore that drops onto the Mercedes hub register. The mounting pattern is 6 x 112mm. Weight lands right around 11 pounds, 4.7kg, which is what you'd expect for a solid rear disc this size.

It's sold as a single rotor. You'll want two to do the axle, and it's always smart to do both sides together so the car brakes even and wears even. Fitment covers a wide swath of the lineup. On the E-Class you're looking at the 300TE, E300, E320, E420, and E430 from roughly 1993 through 2002. C-Class coverage runs the C230, C240, C280, C320, and C350 from 2001 to 2007, plus the C36 AMG. The CLK line is covered from the CLK320 and CLK430 up through the CLK350, 1998 to 2009. And the SLK280, SLK300, and SLK350 from 2005 to 2011 use it on the rear too. Because Mercedes reused this rear disc across so many chassis, it's worth confirming your car's exact rear rotor diameter before you order, since some higher-output variants ran a bigger rear disc.

Install is straightforward if you've done rear brakes before. Pull the wheel, back the caliper off, unbolt the carrier bracket, and the old rotor comes free once you back out the two small retaining screws. Those screws are usually seized, so a hand impact driver saves a lot of cursing and stripped heads. Clean the hub face down to bare metal so the new rotor seats dead flat, otherwise you'll chase a brake pulsation that isn't the rotor's fault. Most of these Mercedes carry a separate parking-brake shoe inside the rotor hat, so give those shoes and their springs a look while everything's apart. Then bed the new discs in with a series of moderate stops from speed before you ever lean on them hard.

One thing to be clear on: this is a straight replacement disc, not a drilled-and-slotted show piece. For a daily-driven Benz that's exactly what you want. Predictable feel, quiet operation, and a coated finish that looks right behind the wheel. Note that pads, retaining screws, and parking-brake hardware aren't included, so order those separately if you need them. Pair it with a fresh set of rear pads and you've got a rear brake job that should go another 40 to 60 thousand miles.