Stevebfl, you are absolutely correct that the clunk happens when the transmission downshifts while coming to a stop. Sometimes it is barely perceptable, other times it is very pronounced. I have no doubt that there is a lot of backlash in the differential, but, as you indicate, it shouldn't be noticable as long as the engine is always pulling. The car seems free of vacuum leaks, just judging by the prompt engine shutdown, and the fact that the central locking holds for 2 weeks or more, although I have not actually measured the vacuum pressure. The transmission control adjustments were done about a year ago when the vacuum valve at the injection pump was replaced. It was OK for a while but now gradually this clunk has become a problem. I think I may try a different dealership. The local MB dealership was a relatively new start-up, the sold out to one of the old established deaalerships from Dallas. Point is, I am not sure they have an old-time diesel tech who is thouroughly familiar with this.
If, after transmission vacuum adjustments, this is still a problem, I may try a boneyard differential. Can that be done by a reasonably well equipped non-MB shop ? Are special tools required ? Also, for an early 84 300D, is that certain to be a 1:3.07 differential ? Some of the MB manuals do not seem to agree on the ratio. Many thanks for all the info. Mercedesshop has been a tremendous wealth of information for me. Happy New Year to all !
2004 C240 Wagon 203.261 Baby Benz
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