Transmission Suckage. 1987 300D turbo, om603

[kg6mov]

87 300D turbo, om603, slushbox, too many damn miles, etc, etc.

Since I've had it (5 months) the trans has always been, well, less than perfect.

Bought it knowing there was a leak at the pan gasket. Drove fine, has to be topped off every once in a while. Lately though it's not so much with the driving fine. The lag between shifting into a gear and the thunk that tells me it's actually putting power to the wheels has gotten longer.

Today it started doing a new trick, when accelerating it kinda sucks up to about 3k rpm then the tach stays put while the car accelerates up to the shift point.

I'm going to rip into the thing and do the gasket thats been sitting on my desk for ages, is there anything else preventative or adjustment wise I can do? If this was my jeep I'd be doing solenoids and band adjustment but I can't make heads or tails of these things, it's like somebody used engineering when designing the sucker!