The H&R 97-04 Mercedes-Benz SLK R170 Sport Spring kit (part 29769) is a set of four lowering springs for the R170 SLK chassis, built to close the gap between tire and fender and lower the car's stance. Owners on user forums say the set works with factory dampers, though many add firmer shocks to match the stiffer spring rate. For a buyer comparing it with a generic drop spring, the H&R set is the better match for an SLK230 Kompressor, SLK320, or SLK32 AMG that also sees occasional track days.
Compared with stock springs, the H&R kit is aimed at reducing body roll and sharpening turn-in, which owners describe as a clear handling gain on the street. Owners on user forums describe the ride as firmer than stock but more composed than the cheaper drop springs they had tried, so the price is justified mainly by the handling result. Lowering also changes suspension geometry, so the real cost of the upgrade includes an alignment and, for larger drops, rear camber hardware.
Fitment is centered on the 1997 to 2004 R170 SLK range, and owners report that the final ride height depends on the factory rubber spring pads and on whether the car has factory sport suspension. Front installation is the simpler job, while the rear springs can require an MB-style coil spring compressor and, in some cases, lowering the control arm for clearance. Search terms that match this product include H&R 29769 R170 springs, SLK230 Kompressor lowering springs, SLK320 sport springs, and R170 fender gap fix.
Owners on user forums report that rear camber moves noticeably after lowering, and that the R170 has no factory rear camber adjustment, only toe. Many owners add rear camber arms and always get a full alignment after the install.
Owners on user forums say a standard compressor often cannot compress the rear springs far enough, and that an MB-style coil spring compressor is the tool that works. Front springs are generally easier to remove.
Owners on user forums report a firmer ride after the swap, and several pair the springs with upgraded dampers. One owner reported blowing out front shocks while running the lowest pad setting.
This is a moderate-difficulty job that owners on user forums describe as doable at home with the right tools: a jack and jack stands, a socket set, and an MB-style coil spring compressor. Fronts are usually straightforward, but the rears can be stubborn, and some owners had to drop the lower control arm to get the spring out. Choose your spring pad combination before you start, since owners on user forums ran different front and rear pad thicknesses to reach a level stance. Plan on an alignment afterward. Some owners have paid a shop, with one reporting about 3.5 hours of labor.
