A little history... So the L2800 came out in 2004. From 2004 until mid 2006, HST models, a “Ratcheting Noise” may be heard during engine de-acceleration while the rear PTO is engaged. Before the PSB-2005-052-A, which changed the over ridding CAMS to locking CAMS, there was another Product Service Bulletin (might be the same number but without the "-A") that instructed dealers that had coustmer complaints about the noise, to install a dipstick where the sight glass was and to add (I think) 1.85 gallons of extra hydraulic oil to submerge the CAMS under oil.
If your serial number is below 57744 - you could have gotten that set up... To answer your question, call a dealer about this and see if it's the same type of dip stick that they use in the newer machines...
I had a copy of the bulletin on an old computer but can not find it in back ups... {EDIT} Found it, I uploaded the PDF; but just in case you can't read it, I made Jpegs of the 3 pages.
