Any tips on Flex Disc Replacement for '86 300E?
 

The service manual and CD doesn't have a section on this subject alone, just on removing the whole driveshaft. Can the discs be changed without pulling the driveshaft?

The disc can be changed without COMPLETELY removing the drive shaft. You must remove the exhaust system, at least lower the front portion. You will have to remove the right front carpet and disconnect the oxygen sensor before lowering the exhaust system.

Once the exhaust is out of your way, mark the joints at both ends and the center connector, so that they go back together in the same alignment to prevent imbalance of the rotating parts.

Lower the center bearing and then unbolt the flex disc. The front one fails because of heat. The rear one rarely needs replacing. The disc must go in correctly, one set of holes is at a slightly different distance from the center than the other set. Make sure the bolts you use clear the transmission housing when rotating. Rotate the driveshaft before putting up the exhaust to check that the bolts are clear.

Good luck,