I see this part in TM's online parts catalog, but I'm still not sure what it is. At first, I thought it was the special bolt at the top of the lift arm, behind the outside cover, but that isn't it. Can you give us a clue where you found it? And why you need to replace it?
A photo always helps, if you can take one.
By the way, what year/model TM do you have? It is helpful to add that info either in your signature line as I have done below, or your account info that shows up on the left of your post with your avatar, as many others have done. Otherwise, your question is kind of like asking "I need to replace a bolt in my car. What do you recommend?" Not nearly enough info.
To add the year/model/location info - and set a lot of other useful options as well - look at the left end of the blue bar near the top on most pages, and find "User CP" (User Command Post). Click on it, and scroll down through the extensive menu that pops up. It is worth spending some time exploring this menu. There are lots of good option choices in it.
Bill
