I had the rumbling fan cleaned by a pro. but the rattling didn't go. I just finished replacing the fan on my 27'' Thunderbolt Display using these instructions, and so far so good after 3 hours. It usually started the rattling after 30mn!
I purchased the fan on eBay. There were a couple available then.
I got the fan for $18 and spent 30mn on the job. At the Apple certified spot in town, they were going to charge me $250! I bought this Apple Display second hand for $250! and now it is back to its old self, working like a charm :)
Thank you very much for this web page which walked me through the process.
By the way, for a succion cup I used the two small ones that are attached to my soap holder, from the bathroom tiled wall; worked just fine and I didn't have to spend $20 to buy one.
cheers
