Hi there!

I've just replaced the flex disc/hardy disc on my 300TE, 89. Hoping this would reduce my hard shifting. But no...
Symptoms

• Hard "thunk" when going into R or D (Makes my brakes "sqiiiiik")
• Hard "thunk" in all the gears upwards, down a bit better
• Better when very low trottle

It could feel like it might be the diff, since when I was turning the propeller-shaft it seems like I could replicate the "thunk" - it was from turning first one way, and then quickly change direction. - not totally sure about this, was sweating under the car in 30'c - but will follow up on this.

I've been reading about checking vacuum pressure and adjusting the modulator.
I've read these two pages: http://www.benzworld.org/forums/w201...l-replace.html and Mercedes-Benz Transmission, Steve Brotherton, ImportCar, February 2002 but they are for the 722.4 and/or diesel. But I'm having difficulty in figuring out where to plugin a test Gauge and what the pressure should be?

Could a gauge like this work: http://www.ebay.co.uk/itm/Oil-pressu...item5d4cce5be2 ? and where to plug it in?

I also have a vacuum "fuel efficiency" gauge, which works as it should, had a leak once, fixed it, but no change in the shifts. But I don't know if its related to the gearbox vacuum or usefull to leak finding.

The other things I will try is changing the oil and look closer on the diff/driveshafts. But I would really want to know about the vacuum is fine for the gearbox