The starter on my '84 300tdt has been 'going' for about a year, and, as Murphy's Law dictates, it's in the single digits here and the starter no longer engages. I got one from the junkyard and put the MB up on jackstands. Turns out, the bottom starter bolt was missing and the top one had backed itself almost all the way out. I torqued them in and the MB leaped to life at the touch of the key, as usual.