Pontiac Repair: motor shakes, 1987 pontiac 6000, pontiac 6000

Question
I have a 1987 Pontiac 6000 with 278000 miles. Don't laugh; it normally runs great and doesn't use any oil. I have to see how far it will go.
Anyway recently the motor started shaking when it idles. When accelerating it smooths out. I replaced the top dog bone because the bushings were shot and the lower front motor mount. The one under the pulleys appears to be okay . I can't tell about the lower rear nor do I know how to replace it. Others have told me it's not the mounts , that somthing else is making it shake. It is not missing. Can you help?

Thanks,

Paul

Answer
Check the flexplate bolts.
There should be a cover attached to the transmission, at the bottom of the bellhousing near the oil pan. take that cover off and you should be able to see the flexplate and torque converter. Three bolts hold the flex plate to the torque converter. You will need to get them 1 at a time and then turn the motor a little bit to get the next. If they get loose it can shake like that. I think you are supposed to use loctite or something equivalent on them. After 278k I can see why they came loose.

Good luck!