Replacing rear flex disk on '80 SD, tips please.
 

The rear flex disc on my '80 SD is shot. The rubber is all crakced and coming apart, hey what do expect for a 22 year old piece of rubber. So I bought a new one, now for the replacement. Is it as simple as unbolting it from the drive shaft, or is it more involved than that? I was informed by one of my indy's mechanics that once that disk lets go, I'll be on the side of the road with my driveshaft lying on the ground.

You oughta do the front too.

You'll need a 19mm socket and a 19mm box wrench. Undo the three bolts that hold the drive shaft to the disk, then the three that hold the disk to the differential. You might need an impact to accomplish this (I did the other night, only took a few seconds to disassemble). Using a suitable large pry bar or sturdy screw driver, separate the shaft from the disk, then pry the disk off the differential. You might also have to loosen the large nut at the carrier bearing to allow the shaft to slide forward a mite, then again you might find that nut loose. Assembly is reverse.

After 22 years, you might find that the steel collars inserted in the rubber may have seized to the shaft flange or differential flange, requiring a little more prying. Be sure to set the car securely on a good set of stands, keeping safety first.

i just changed mine this summer,,,its a pretty simple job,,,on the rear one i did have one bolt that rusted into the metal insert of the disk,,,had to take it driveshaft and all out and put it up on the bench,,,some penatrating oil and a few licks with a rivet hammer changed its attitude!!!,,,lucky i bought new bolts with the new lock nuts!!!,,,

my disk weren't that bad, i changed them because my carrier bearing was trashed,,,i had it all apart so i changed all,,,you may want to look for play in the carrier bearing as well,,,once you get the exhaust system off its all pretty simple,,,

good luck,,,