My car has roughly 200K on it. Lately the transmission has been driving smoothly when I take it easy on the pedal. However when Im the least part aggressive the transmission shifts as if the rear ends is getting kicked by an elephant.

What could it be, I dont see any vac lines off and my locks work correctly so Its getting some vacuum. I read that the Bowden cable has nothing to do on how rough the shift is.

Whwn I go from park to drive it goes in less than a second and basically every transmission movement goes in quickly. my car is a 1995.

I see others with symptoms kind of like mine but no actual conclusion. Im hoping this group can help me in my initial question.

The locks are on a completely independant vacuum circuit which originates from the vacuum pump under the rear seat.

Aggressive shifting at full accelerator is considered normal, But it should feel like the whole car is being pulled by a chain not being kicked by an elephant, if it shifts softly at low revs that means that the VCV on the injection pump is working. You might want to check the condition of the driveshaft flex joint (specially the front one) for wear - its the cushion type which when worn out will also clank.

best would be to get a vacuum gauge and inspect the entire vacuum system for leaks.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

THis extreme shifting is not normal since the car shifted great previously. Now it goes back and forth. for awhile it shifts smooth as rain and then for awhile its like getting rear ended when shifting!

some rubber joint in the vacuum system is leaking. best worked with a vacuum gauge then wiggling the pipes to see what is leaking.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

^x2

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Jim

This sounds like the same problem as with my car.

Ok Im going to start this process over and go over my tracks again. With that said what is the best way to inspect for a vac leak, especially if all connections are on. Do I do it with the car running? If so where does the gauge get hooked up?

Or is it with a mityvac and if so where do I hook this up?

I would test individual vacuum circuits, and just connect a gauge to the easiest take off point, e.g. the shutoff brown line. But ideally for transmission problems you should hook up the vacuum gauge to the line at the modulator - Infact use a mightyvac to force the modulator to shift softly. Hence determining the problem.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

If I get you right I just take off the line to the modulator and hook up the mityvac directly and pump it up to say 22lbs and then drive the car and see how it shifts when Im aggressive with the throttle. If it shifts then the modulator is bad or needs to be adjusted? However if the modulator cant hold the vac it will also prove that the modulator is bad. Is this thinking correct?

If the modulator cannot hold vacuum its bad. what you need to do is to apply vacuum and see if it shifts smoothly (too much slip)

the idea is that no vacuum to modulator would result in snappy shift (elephant kick)
most vacuum = slippy transmission

you can test it with the above two results in mind.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Hey everyone,

I also have a 1995 E300 with 120k miles. Lately I have been having what I think are transmission problems, particularly the "elephant kicking" when trying to shift. If I accelerate hard, the car will do a yanking back and forth thing a few times before it shifts, sometimes I have to let off the accelerator to get it to shift. I also have a problem with a hard brake pedal sometimes a few minutes after start up, and the engine has been taking a couple seconds to shut off sometimes. Are these problems related? What is the most likely culprit for the transmission shifting issues? At first I was thinking it was the transmission, but now I'm thinking it may be a vacuum issue. Also, I experienced an abrupt 15% decrease in fuel economy about 25,000 miles ago. I use Bell Performance Deezol (an incredible fuel additive) to keep injectors clean and what not, but I'm wondering if all these issues are potentially related. My most immediate concern is of course the transmission. Also, if I do have to replace it, does anyone know how to get it remanufactured? or where to get a reman transmission? I understand remans to be better than rebuilt...

where is the modulator located on the 1995 E300?

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1995 E300 diesel

Its in the same oldschool location, driver side of the transmission with one plastic vacuum pipe going to it.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

You have a vacuum leak somewhere - which is causing the brake pedal to go hard, the trans to shift funny etc, There would be a yellow "Y" behind the brake booster that has some vacuum lines, the rear headrest vacuum line also originates from here, check for rot of the rubber ends (cable tie them) and put some rubber protectant on them. My car had the red line that leads to the vacuum reserve tank in the right fender cut, it was pretty stupid where it broke as I had to pull it from the other side, repair it and fish it back.

There are also a bunch of vacuum lines under the manifold, which can be checked by removing the crossover pipe, You should buy a hand held vacuum tester and test each circuit, you will solve the problem eventually.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)