1993 Pickup driveshaft question

I have a 1993 Nissan pickup, 4cyl. 2 wheel drive. It developed a nasty rattle last week, which at first I thought may be the cat converter breaking up or something.
I got under the truck this afternoon and noticed that there's a ring, or bushing, not sure what to call it, on the driveshaft at about the middle of the truck that is just dangling there. It appears the rubber that held it in place had deteriorated, and it makes sense that this is the source of the rattle as it's most likely bouncing on the driveshaft as I drive.
My question: what is this "ring" and am I in danger driving the truck as is? It has suffered no apparent loss of performance.
As a side not I've owned a LOT of vehicles in my time, and this '93 4 banger with 184K on it (and believe it or not for upstate New York entirely rust free) is the best little buggy I've had.

Anyway...any advice/suggestions/warnings much appreciated.

that is the carrier bearing for the driveshaft.
replace it .
do not drive it til you do .
or you can damage reaend ,trans and end up buying a new drive shaft..

Hi Zane,
Thanks for the reply. I have driven the truck no less than five hundred miles since noticing the rattling. As I said there has been no noticeable loss of performance or anything. However, I will heed your advice.
I did a search for "carrier bearing" for the truck, and at Rock Auto came up with a few possibilities which are: Drive Shaft Center Support Bearing and Drive Shaft Center Bearing. I'm not sure which it is.
Also, any idea what the level of difficulty is to replace it? I'm in the construction industry and have no problem with mechanical aptitude, but if it's a "hairy" job I'd rather farm it out.

Thanks for your time!


JD

they are both the same item.
the carrier bearing can be a little tricky to replace but it can be done in the driveway.

the main trouble is getting it off,
the second is the shaft is probably dirty and a little rusty so the bearing does not want to just slide on..
the third problem concerns the balance of the drive shaft..

i have done the job and found it easier and more cost effective to replace the whole drive shaft with a known good one (that is "used ").

you could probably pick one up at a pull and pay for about 50 us..

what area are you in??

also you can post on several site to find a used one.
i have several of those drive shaft but shipping them is cost prohibitive..

my 87 nissan truck has over 500 k miles on the original motor.
it does have rust though..

I would suggest that you take it to a drive line shop, they have the equipment to install a new bearing for you and can balance the drive line as well.