At winter service mechanic was after me to have the rubber engine drive shaft dampeners in our 9000 series tractors replaced. Estimated something like a $3000 job. Said they should be replaced every 5 years and the tractors are 11 years old now. I looked at the rubber on the back one (can't see the front one easily) and I saw no weather checking and it looked black and good. Told him I think I will not. Ask what would happen if they went out. He said shaft will spin in the rubber, create lots of smoke and tractor stop dead in its tracks with no hydraulics but otherwise no damage.

Anyone have these fail in the field? Hours and age?

This is kind of related to the harmonic crankshaft balancer below - do these really need replaced or is this a "just in case it might go out we better fix it" thing. If they blow up in the field how hard are they to replace?

I will say that we had the cab mounts replaced because the rubber was getting tired and shift linkages were getting out of adjustment. Maybe this other rubber stuff needs replaced too. Looking for input and experiences from others. Don't mind keeping the tractors maintained, just don't want to throw money away.

John