Clunk - left rear 190e 2.6 uni-jnt or xmsn

[Paul Bennett]

1994 190E 2.6 120k miles
Back up a short distance slowly then shift into drive and slowly accellerate...clunk. Sounds like the left rear takes a half turn before engages. Could be in middle of car but sounds like drivers side. Occasionally get the noise when going into reverse. Drives/shifts/sounds fine when warm but still has the clunk. Slow shifts when cold. Clunk is new and scarry.

Is the problem likely to be:

1) Universal which needs replacing
2) Bad differential?
3) Drive line problem?
4) Transmission?

I'm unfamiliar with the structure of a independant rear axel but seem to remember a front wheel car doing this once when the universal joint needed replacement.