Here is the belt online: http://www.ebay.com/itm/Pioneer-CLD-53- ... SwjVVVzlHp

It doesn't state it'd work with the player specifically, but I heard from someone that there isn't that strict of rules to replacing a Pioneer player's (at least) loading belt - stating he'd switched out with a cd-player's belt and it worked fine. So I thought this loading belt on ebay, which was designed for same-brand laserdisc players, would probably work. Am I right in thinking that? Thanks in advance!

The issue I'm trying to solve by the way is the tray sometimes stalling when inserting an LD and ejecting after (it always works with CDs though). I found that manually aiding a piece in moving upwards fixed the issue temporarily. So would that be a loading belt issue?

If it's the mechanical assembly that you're having to raise upwards to get the disc to load then yes, it is probably the load belt. SCQ 3.6 is the belt that you want to use. I'm not sure what size the belt you referenced on eBay is, but SCQ 3.6 definitely works. I had this exact same problem with a D703 that I picked up for 20 bucks, and Kurtis Bahr set me off and running. He told me that a 4.0 is a bit too big and a 3.6 is a bit too small compared to the OEM Pioneer belt, but that the 3.6 is the better option since the potential for the belt to slip is greatly reduced. Make sure you clean the grooves of the white plastic where the belt is when you replace it as it's probably dirty. If you ever need to get this unit repaired, I can vouch for Kurtis, he does great work.

Do an internet search on SCQ3.6 and buy one. The ones on eBay don't state the size they are or if they are the Pioneer belt. Though after I started telling people what to buy a few years ago they started showing up on eBay.

Yes, definitely don't use the 4.0 — I tried that with my D704, & it only made the problem worse. I shall have to try the 3.6 instead.