Thanks to all the threads regarding transmission vacuum related issues, I've successfully adjusted/repaired linkages, vacuum leaks and vacuum modulation on my 81 300CD Calif. emissions. The trans shifts just like a gas car once engine temp is normal. My question is what would cause a delayed harsh shift thru all gears when the engine is cold for the first 2 to 5 miles of use? I use synthetic ATF and the trans was replaced 2 years ago by a rebuilder. I've never had a vehicle, gas or diesel that changed how it shifted so dramatically from cold engine to warm engine. I have great part throttle kick down up to 56 MPH good shift spacing around town. Shifts to 4th at about 35 to 38 on light throttle in town, but when cold I get the bang shift first to second and delayed second to third shift. If I didn't know better, I'd say the fluid is much thinner warm than cold, but its synthetic? Could it be a vacuum leak that leaks less warm? Makes no difference doors locked or unlocked, climate control set to auto or econ. Also the supply hose to the EGR is disconnected and plugged.

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81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

1984 300d Turbo 141,000
Push In Last Far Right Botton On A/c Heat Controls At Start Up To
Find Leak Or Weak Vacuum, May Be A A/c Heat Vac Pod Leaking, Check
Gas Flap Cover Stays Lock Over Night All Doors And Trunk Lock,shut Off Working,

I'd say that your situation is best described as typical. With the shifts setup so that they are crisp when the trans is warm, you're going to get some banging and a slight delay when the trans is dead cold. The SD does the same thing but, it's not objectionable and it only lasts five minutes or so. I usually keep it in third gear and attempt to keep it rolling to warm it as fast as possible without any shifts.

My fresh rebuild does the same thing. I think a small part is caused by using more pedal when the engine is cold vs. hot which bleeds more vac.

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Adam Lumsden
(83) 300D
Vice-President of the MBCA International Stars Section