Originally Posted by willrev

Hello again,
Been working on the 82 300sd. Got the first two new glow plugs in without taking off the fuel lines. Knuckle buster. Needs some wratchet box wrenches. Will go purchase some before I finish the job.

Trying to run down the problem with the clunk sound with each successive downshift in the transmission. I checked all my vacuum lines under the hood. All were connected well. Is the dark black line that comes off the front of the engine and goes to the brake booster the main line??? YES

Right in front of the brake booster coming off that big black line is a rubber fitting. Out of that fitting comes a small diameter vacuum line that goes to the hookup on top of the IP. It was plugged with soot. I cleaned it the best I could and cleaned the black T fitting with an ice pick and lots of soot came out. But I still have the noisy downshift, but it definitely does not seem as "rough" when it shifts down. I think this helped. Are there any other possible areas that the line could be clogged?? There is a colored plastic orifice( or vacuum restrictor) between the line from the brake booster to the Tee on the vacuum control unit on the IP. Make sure that's not clogged, but don't drill the plastic hole out, either. The other side of the Tee should be connected to the modulator on the transmission

I was referred in an earlier post to the T fitting coming off the pump before the line goes to the tranny. I hope this one right in front of the brake booster is the one. Please advise me if you can. If you haven't done it already, I would bypass the EGR's vacuum control. This eliminates any leakage in those crossover valves from affecting the transmission shift

willrev@earthlink.net