1993 240 Wagon, B230F head swapped out for older B23 head last winter, barely driven in 2013 because of loud exhaust (didn't have time to fiddle with it), exhaust fixed, runs fine.

Issue is shaky and rough going in first gear (automatic), shifting into second gets better and by third it's all fine.

Hoping for easy fix?

 

Did you check your fluid level?

Also, do you notice any deceleration noises or vibrations?

 

also check the center bearing on the driveshaft. the bearing itself can be shot, or the rubber donut it sits in can be worn out, at lower speeds this can cause the driveshaft to rattle around, but it can smooth itself out at higher speeds.

ditto, bad U joints can, under some circumstances, make more audible noises, vibrations at lower speeds.

 

Sounds to me like a low speed engine misfire. You need a tune up first, go from there.