38 inch mtd deck belt tension

Hi guys,

I recently replaced a broken variable speed belt on my mtd 13.5 hp lawn tractor with the 38 inch mower deck. The unit is a 1997 model with a model # of 137f450f522/ Unfortunately this number is not found when searching mtds database, I did contact them and they explained this is sometimes the case and sent me a parts list for the tractor. The issue I am having is that when I put the mower deck back on, the deck belt has a lot of slack, even when lowered to the mowing position. The unit is a 2 pulley deck with no idler, and since I made no adjustments to the deck, and am using the same good belt that I just took off, I am baffled as to what has gone wrong. Any guidance would be greatly appreciated.

Thanks,
Adrian

also wanted to add a second related question. When the mower deck is removed, should the deck stabilizer bracket hang loosely, or should it remain under spring tension?

There is should be a large pulling the deck rearward. Item 50 on following diagram.

Thanks for tbe reply. The spring you referenced appears to be in place.i do seem to be missing the spring numbered 51 in the attached diagram and wondered if it might be the culprit as well?

Wish I could help further but its been over 10 yrs since I have worked on this setup and there 100s of mowers thru since that time.