Snapper rear end locked up.

I've got two Snapper Hi-vacs with 33 decks. One is made around 1979 and one is made around 1999. Usually the parts between the years are interchangeable for the most part.

I used to have a 2001 model and I wore lip off the deck so I robbed the heavier deck off the 79 model and installed it on the 2001 model.



After buying a new Craftsmans (Husqvarna), The Snapper became my backup mower. Then after acquiring a Troy Bilt (MTD) through helping someone move, I decided I didn't need the Snapper anymore so I sold it.

I'm wanting to see if I can take both of these mowers and make one running mower.

The 79 model has an 8 hp Tecumseh engine on it. No deck, no rear wheels (used on my daughter's ATV), front wheels are good, steering is good.

The 99 model pulls but is locked up in 3rd gear. It has a good 15 hp Kohler engine on it and a good deck. The front end is messed up on it. Mom or Dad hit something hard and broke it so I welded it back together but the steering has some issues. Front tires are bad but the rear tires are good.

I robbed the deck off the 79 model because the rear end locked up and it won't pull but I can still shift between gears.
Dad's 1999 model, it pulls but the transmission is locked up in 3rd gear.

So the plan is to take all the good (or better) parts from each mower and build a Frankenstein Snapper.

I think the transmission in the 99 model has some major issues going on with it so I'm probably not going to spend any money trying to repair it. But I'm wondering if the 79 model is an easy fix.

Does it sound like the chain has broken and is putting the rear end in a bind? Wonder if I could just pull the chain off the 99 model and use it in the 79 model?

Anybody ever seen this? Any guess what might have caused the 79 model to just suddenly lock up?

If the rear wheels won't turn at all, it could be the chain like you said? I've also seen where one of the bolts holding the planetary gears in place in the differential have backed out and caused one of the gears to dislodge or the bolt caught somewhere on the case and locked it up. You can count the links of both the chains and see if they match. Those bolts holding the planetary gears in place in the differential have an interference type thread to help lock them in place once tightened. Snapper recommended replacing them if ever removed. I've used the red threadlocker compound on them and never had any trouble reusing them.