Seat Belt Reel Problems

Hello.

Just over a month ago I bought a 2006 ford fiesta zetec climate. A couple weeks after I got it I noticed a noise inside the car toward the back. I plugged the seat belts in, because I realised they knock against the plastic, but still had a noise. I found out that it was the reel itself on the rear seat, drivers side. The noise is like a constant vibrating, and is sometimes easy to hear, and sometimes not. I obviously want to sort it out because it quickly gets very annoying.

I took the plastic cap off of the side of the reel, and a white plastic piece flew out. When I put the piece back in the seat belt keeps jamming now. It will work fine if you take the piece out, but it is obviously in there for a reason. The reel on the rear passenger side has starting making the same noise recently as well which is very frustrating.

So now I am left with two annoying noises and am not sure how that piece goes back in the cap on the side of the reel.

I have searched high and low on the internet and can't find anything. A friend told me to post on this site so I thought I'd give it a shot.

I would greatly appreciate any help.

Thanks.