'96 SL1 Transmission Clunk When Shifting

1996 Saturn SL1. 125K miles. Has been a good car. Current problem when
shifting from Park into either forward or reverse. Engine moves violently
and loud clunk heard. Also experience the same loud noise when driving and
shifts between 2-3 and 3-4. It seems to shift much smoother from 1-2.

I have done some research and identified that the Torque Axis Mount may be a
problem. I looked at the mount and do not see any obvious problems with
cracked/aging rubber, etc. I see a slight spacing in the front and rear
between the rubber and the metal mount holder. When the car goes into gear
and the rubber gets compressed either to the front or rear of the metal
mount I can slip a large screwdriver (1/8 to 1/4") in the space between
them.

I have also seen and read stories about bad valve bodies, but am not sure
what the symptoms of a bad valve body would be. In any event, there are no
error codes and the transmission shift points seem to be normal. It is just
the loud clunking, possibly from too much engine movement that seems to be
the issue. As it is dark tonight and late, I have not had the chance to
crawl under the vehicle to look at any of the other motor mounts.

My question to the group is what is the most common cause so I can
investigate this further. The car is my son's and we need to get him safely
back on the road. How much space should there be in the Torque Axis Mount
and does the movement I am seeing seem right when going between gears while
the vehicle is at rest and the parking brake is applied? I am tempted to
take a quick look under the car if the other mounts look good to replace the
TAM since it seems easiest. Any advice or thoughts from those who may have
seen this problem before? Responses ASAP would be appreciated.

Bob