I have both a 1979 and 1980 300D. The transmission control is by vacuum on the 1980 but on the 1979 there is no vacuum tubing to the tranny. How is the 1979 tranny shifting controlled?? Also the kickdown switch is electrical. How does that function on the 1979.

I am having a problem of very slow to no acceleration on the 1979 when it starts out on a hill. Feels like fuel starvation due to algae buildup but cleaned tank, tank filter, replaced pre-filter and spin-on filter. Also replaced air filter. It is embarrassingly slow I am afraid someone will plough into rear.

Any ideas???

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Dionysius

I am now of opinion the '79 is a mechanical linkage to throttle??? How unlucky to have different controls on each car!!! Just came across this:

https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/615/30-300.pdf

On the '79 it has Engine Model: 617.912 and Trans Model: 722.118 and I find the 1980 has same engine and trans. Why in hell did they switch the controls???

So for the 1979 should I be looking at Section C on page 10 of 17 in the PDF????? However I find the pics and descriptions impossible to figure out.

But mechanical linkages are unlikely to change so what else could the problem be???

Car drives and shifts beautifully on level terrain. But get it on a hill and it is a dog.

__________________
Dionysius

Hello! I have a 1980 300D (non-turbo) with 107,000 original miles on it. A few weeks ago while driving, I came to a stop light and upon trying to accelerate away from it, found that my transmission had stopped engaging completely. It does not engage in Reverse or Drive or any other gear at all. Just feels like it's in neutreal whenever I shift it into any gear.

When I got it home, I looked it over and found that the vacuum hose connected to the nipple on the transmission vacuum modulator cap had broken off and the hose was just hanging there. I found a new modulator cap and replaced it, thinking that would solve my issue, however, no luck. I have checked all the vacuum lines, and everything looks good and there is good vacuum. The drive shaft is attached and intact everywhere, and the shift linkage seems to be working properly as I can hear it engaging gears in the transmission. Is there any thing else I can look for or try/do before taking it into a mechanic for a new transmission? It's hard to believe that the transmission would have failed internally at such low miles. Really hoping I am just missing something small. Any help would be greatly appreciated! Thanks!

ms:

When the selector lever is placed in Park is the car prevented from rolling, or can it be rolled when the brake is released?
If it can be rolled in Park, do you hear a scraping sound in the area of the transmission?