Hello, thanks to all on this forum for making it what it is. I have saved immeasurable amounts in both money and time in the assistance you have all provided in your posts. One thing that has eluded me for the past year with no resolve until a few days ago was the darn clunking that seemingly came from the rear end whenever shifting up or down under light load. My car has 157k, is a 1985 300d turbo Californina model and i figured that all the stuff I replaced to chase down this clunking would benefit the car even if it didn't fix the clunks. The problem, just as many had already pointed out, was vacuum. My initial ignorance about Mercedes vacuum systems and poor troubleshooting strategy has tought me several things. First, the reason I bought this car was to save money and enjoy a first class car from a build standpoint. But, I feel obsessed with making everything work properly and even after I change the oil I almost feel an itch to change it again after a week, but resist until 2-3k (I bought DELO 400 from Walmart for 1.08 a qt). I learned most importantly that I need to troubleshoot by learning the system more thouroughly, i.e. - I need to buy the dang manuals and read them as opposed to doing everything from my supposed all-encompassing mechanical ability (I thought). I wound up learning backwards the entire vacuum system only to find the culprit being at the end of my learning journey. The Californina model I have has a diaphram in the turbo in addition to the wastegate that controls boost. The diaphram had developed a small leak and caused an intermittant vacuum problem affecting everything, but most significantly the shifting. While I have been unable to find a replaceable diaphram (anyone have any ideas?) I simply disconnected and plugged the vacuum hose leading to the offending part. The first clue for me shoule have been when I hooked the mighty vac up to the tube going to the tranny modulator and assessed the vacuum dropoff that occurred (most of the time) and gone backwards from there. The reason why i strayed is that the clunk seemed far too significat to be caused by vacuum, like it was eminating from the rear end, but happily it was not from there. I will stop writing there, as I, like all of you, can write novels about our adventures with hese cars when our wives are telling us diner is ready and we say, "just a minute" and come in only after we are threatened. Once again, thanks to all of you for your guidance. Adam Bush