190e auto transmission .

[nuventure]

I recently bought a 1984 190e ( just 40,000miles ). I am Delighted with it but was disappointed with the less than smooth auto box ( I know, sounds familiar ! ). Have had lots of genuine helpful advice through the various MB links and was resigning myself to living with it, or at least having the vac mod checked out ( fluid and filter having been changed ). However, having run a couple of tankfuls of carb/injector treatment through the fuel system the auto change has improved significantly. I can only assume the vacuum line from the manifold was maybe gummed up slightly and now isn't ( the car has probably been under used if anything ). It's certainly worth a try before having a delve. Thanks for a great site to all concerned. Dave, UK.

[stevebfl]

Automatic transmissions with vacuum modulators have their shifting significantly affected by how the engine is running. The more power the engine developes the less need for throttle to achieve speed. Less throttle translates into more vacuum.

Thus if it takes about 15 horsepower to maintain speed at fifty (this is the average value we use for sustained speed on a dyno) and ones accelerator is at 15 % then one will have more vacuum than if it takes 20% throttle to make 15 horsepower.

There noted for hitting when they shift. They are not smooth shifters...if this is what you are in reference too.

[nuventure]

Thanks for the feedback guys and reassurance. Dave.