In a message dated 12/8/99 10:20:58 PM Eastern Standard Time,
Rubatoguy@MINDSPRING.COM writes:

<< Does this sound like the Sachs clutch problem, or could this be a
 problem with the hydraulics in the clutch mechanism? >>

Sounds to me like you might want to check the condition/wear on the motor
mounts.  This has been a symptom I have experienced in several
vehicles(including my '82 Diesel).  Every time, replacing the motor mounts
fixed the shuddering.

Good luck!

Stefan