tach also, I tried to find a competent and possibly inexpensive mercedes specialist in Berlin and the surrounding area several times, who can track the hydros with my 500se with motor 117. however, I noticed that the workshops with which I telephoned offered me a hydro-punch exchange for (only material) 600,-. certainly benz costs a little more, but the repair method allows me to see how much idea the colleagues have. with the corresponding special tool I would also do it myself (with the help of my mech). so I try to find someone on this way who gives the tool or adjusts the hydros. mfg ben