Tranny Vacuum Dashpot Location for 1980 300D

I am a reletively new owner of a 1980 300D, and learning as I go. I've recently been trouble shooting the lack of heat, which means the vacuum system. I've got heat back, but the tranny feels like it is slipping as it shifts gears. I purchased a transmission daspot, but the car doesn't have one currently installed. Should my 1980 300D have a dashpot? If so, where should it be installed? Your help is appreciated.

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Diesel Engine Specific Aid

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Questions and Answers

Chassis Model Number

W123

Location

The green dashpot if installed is inserted in the vacuum line just before it goes into the top of the vacuum operated transmission shifting valve on the rear top of the injection pump. This dashpot softens the oscillations of the vacuum being delivered to the valve. A slipping problem indicates either too much vacuum being supplied to the modulator, a malfunctioning or out of adjustment modulator, or a worn out transmission. If the fluid smells burnt messing with the vacuum won't help. 1980 and 1981 non turbo transmissions are notorious for their shifting problems. My new Advanced Transmission Troubleshooting and Adjustment manual is nearing completion and should be done by early March.

Thanks

Thanks for the information about where the tranny dashpot goes. Prior to replacing the 3/2 Way Vacuum Valve on my 300D, the only time the transmmission did anything out of the ordinary was hard shifting from 1st to 2nd gear when it was cold. Once warmed up it was shifted smooth as silk. I asked a mechanic that supposedly knows MB diesels and he said it was normal for it to shift hard until it warmed up, and that was how MB has designed it so that the transmission would warm up sooner. I've ordered a mechanics manual because I suspect that the vacuum system has been "modified" by someone along the line. I'll be looking for your new transmission manual. If you don't mind I'll keep asking as I go.