Mercedes DCS Transfer Case Rebuild Kit A2511251400

This kit rebuilds the DCS transfer case used on Mercedes 4MATIC SUVs and vans. In the box are an HV-091 / HV-523 BorgWarner-style drive chain, 4 ball bearings, 3 needle bearings, 3 oil seals, 4 sealing rings and a bushing. The case is listed under A2511251400 and A2512800700, A2512800800, A2512800900, A2512801200 and later A25128 numbers.

It fits the M-Class W164 and W166, the GL-Class X164 and X166, and the R-Class W251/V251 from 2005 to 2015. It does NOT fit vehicles with the Off-Road Package, which use the 2-speed case with low range.

On these trucks the chain stretches over time. That causes a clunk or rattle from under the center console when you pull away, a whine that rises with road speed, and in the end a transmission or ESP fault when the chain slaps the case. Replacing only the chain leaves the old bearings in the case, and they often have the same miles on them. This kit lets you do chain, bearings and seals in one teardown. Clean the case halves, check the sprocket teeth for wear, and refill with the specified transfer case fluid.