Troubles with 307D 1980.. Shaking apart..

[swedish307d]

Hi there!

We got som trouble with our 307D with a 616 engine and automatic 4 gears..

The problem is some kind of resonance that firs occurred when shifting between 3'd and 4'th gear now it happens more sporadic on all gear.
The resonance is BIG!!! like a earthquake..
it's a little better when shifting manually as I then can shift at higher rpm. also the resonance does not occur so often when accelerating with "kick down" but always when shifting at low momentum as in downslope.
When I just cruise on highway there is no bigger problems.
The frequency of the resonance is independent of speed but rpm affects it some.

two ways of getting rid of the resonance when driving is to manually shift down, if that does not work it sometimes work to push it into kick down ( full throttle and down shift) so it seams to me as the tranny does not get enough pressure from the torque converter?

on mercedesshop.com they tought it could be some kind of vacuum problem but we cant find any vacuum hoses..

anyone here familiar with the problem?

some pics
http://www.mercedesshop.com/shopforum/attachment.php?attachmentid=35404&d=1155821896
http://www.mercedesshop.com/shopforum/attachment.php?attachmentid=35405&d=1155822062
http://www.mercedesshop.com/shopforum/attachment.php?attachmentid=35406&d=1155822071
http://www.mercedesshop.com/shopforum/attachment.php?attachmentid=35408&d=1155822092
http://www.mercedesshop.com/shopforum/attachment.php?attachmentid=35409&d=1155822179

Thanks and sorry for the bad english..

/Mange & Egil