190E auto control cable stuck

[Fridgemagnet]

My thanks in advance for your greater wisdom and expertise in these areas...

I recently aquired a 1984 190E, and the auto gearbox is very harsh when changing gear, unless I happen to be at 3/4 throttle. After some experimenting, I've decided it's something to do with the linkage between the throttle linkage on the inlet manifold and the vacuum unit on the gearbox. The linkage cable seems to be stuck in the full-throttle position, and won't return. I made the problem worse by giving the cable a tentative tug, and now it won't change into 4th gear until 5000rpm!

Is this a common problem? Would a new cable/vacuum unit assembly cure it? At the moment there's about 10mm of slack in the cable, as opposed to the 1mm spec.

 

[mercmonkey]

you could try wd40 down the cable

I got a special tool for oiling cables, forces the oil down the cable

 

[Fridgemagnet]

Thanks Mercmonkey - that was Plan A, but this assumed the cable was open at the gearbox end. It isn't - the sheath disappears into the plastic vacuum unit on the gearbox. It feels like something may have jammed in the vacuum unit, rather than the cable sticking in the sheath. Any experience of removing the vacuum unit? Would I need to drain the 'box and take off the pan to access it from inside?

 

[mercmonkey]

thats beyond my knowledge....

Autoboxes scare me, they are the devils own contraption