Calling all 124 driveshaft experts

[S Car Go]

I got a real stinger.

The driveshaft on my 86 300E (manual transmission) is in serious trouble. There is a device on the shaft just after the front flex disk. It is a steel ring insulated by rubber. It looks to be some sort of a harmonic balancer or something. My 126 cars do not have it. Anyway the rubber is shot and I need a new one. The dealers tell me that it is not available as a seperate part and I must buy the drive shaft either in sections (front for $500 and aft for $550) or the entire driveshaft for about $800. Also there is a brass & rubber insert at the tranny end of the driveshaft that slides over a pin comming from the transmission at the center of the drive yolk. It holds the driveshaft centered on the tranny output shaft. That thing is oblong shaped due to vibrations caused by the imbalance of the harmonic balancer thingy. Also the center U joint is sloppy. The U joint does not seem to be replaceable cuz it is staked in place. My conclusion is these things are not made to be repaierd and that I should just scrap the entire shaft and get a new one.

My question is: Is there any way to repair these things or are they just throw away when worn out?