hello all, i'd appreciate any insight into my situation. here it is

I've got a 98 Mustang 3.6 litre with a manual tran and it runs just fine. The other day I heard this clunking sound and thought it was just some crap in my trunk bouncing around.

Today I went over some railroad tracks at a fairly low speed and I got the clunking again, this time with some serious vibration on my manual gear shifter.

I became worried that it was no longer crap in my trunk.

I got home and jacked up the car, took a look. The culprit appears to be a metal ring near where the driveshaft connects to the transmission. It looked like it might have covered the u-joint there at one time, but the black rubber gasket (adhesive?) seems to have worn out and now the rings has all kinds of play.

Here are my questions:
1) How serious of a problem is this?
2) Can I just scrape the old black rubber off and use some gasket sealer to re-stick the u-joint-protector thingee in place?
3) If not, anyone have any idea what kind of work would be involved in a better solution?

I'm a pretty mechanical guy... I've changed a water pump, thermostat, radiator, front and rear brakes but no real engine re-build or tranny experience.
Please help!! thanks in advance

 

any ideas?

 

change the U-joints...
I've never changed out U-joints but have heard it is not a hard task and is very cheap.