Are Snapper decks interchangeable? Repair of Diff on 33"

[snapsnap]

I am new to this forum and have a multiple question. I have 3 Snappers, 33"Hi-vac, 331623BVE, I think I broke a gear in differential last week because it jerks when moving. I also have a 28" ,280810BE with bagger which is my backup to 33in . I also have a 25". 250813BE which I have chains and a snow blade for but right now I think it needs a new float in carb(floods air cleaner chamber)
Question1. How hard is it to fix the 33" taking gear case apart etc, or rough estimate to get fixed at repair shop? This mower does an excellent job and I need a RER because my lot is very steep and this type of mower works best for shifting your weight at all angles.
Question 2. I have an extra 28" deck with Ninja blade I bought used, will that fit on the 25" chassis? I want to leave the bagger on the other 28". How can you tell how old these units are, bought them used many years ago. The new RER's don't seem to have good reviews plus have a higher center of gravity and non-floating deck.
All help appreciated!

 

[mechanic mark]

https://www.snapper.com/eu/en_gb/support/manuals/results.productmanuals.html?searchrequested=84954

email Snapper customer support with model numbers requesting information, manuals, parts manual, wiring diagrams.

 

[Carscw]

First thing to look at is the clutch disk. If it has any cracks or chips you need to replace it.
The gear box is very simple and easy to fix. You can Order a rebuild kit off eBay.
Trust me when I say once you take the cover off the gear box you will see how simple it is. There are plenty of videos on YouTube.

Yes the decks should switch out. I believe the only one that won't is a 42 inch.