You know, there is something about this situation that keeps bugging me. The car shifted fine,no thunk, before we pulled and refreshed the head. Also, I had the trans serviced the day before we pulled the head and it got a clean bill of health, and was shifting fine after that also. I first noticed the "thunk" when shifting on my way home after we reinstalled the head. The head needed a valve job because #3 cyl had a chipped valve and #4 and #6 were blowing by the intake valve a bit. This made me wonder "What changed because of the head revamp that might affect the shift?"

The answer I keep coming up with is vacuum. I am wondering if the PO had someone adjust the modulator to "fix" a bad shift that was being caused by a poor vacuum condition caused by the valve situation in the head. If this has been done, I believe that now that the head has been rebuilt, vacuum has been restored and the modulator valve would now be set too high, causing the overly hard shift.

A new flex disk is on the way, but I keep thinking this might be a modulator valve adjustment. Anyone with experience or knowledge of this system care to comment ?

__________________
Andy_M
'98 W140 S320 Black/Black
'06 W164 ML500 AMG White/Grey
'03 Porsche 986 Midnight Blue/Grey