max tire size on 633A38?

Im building my suburban for utility/mudding and was curious as to what the average max tire size it'll handle. My plan is to run a 27x12 or 28x12 mild mud tire. It wont be pulley swapped much, maybe 4-4.5 inch engine pulley on stock trans pulley. It'll go plenty fast for what its intended for, so speed isn't an issue. It will be powered by a stock 12.5 Kohler command, and the tractor won't weigh much more than stock. I am also a fairly conservative driver in the most sense, so it wont be abused much at all. Hope that's enough info for you guys.

Should be fine running those, the 633 is a tough goat. The 12.5 might be an issue if you get into heavy stuff, might not bee enough oomph.

The 12.5 should work fine with that tx. You just have to pick the right gear. I had a 9.5 on the swamp buggy with 31" mudders.

That's what I was thinking Doug, I would have low range if the going got soupy or steep. The Kohler has a big flywheel and has decently low hours, so it should be nice and torquey. Like I was saying before, top speed isn't a concern. I am more worried about grunt and drivability than anything. That's all I need to hear, I wanted to make sure that it wouldn't grenade under a little horsing if it came down to it. Thanks guys.

I cant figure out why everyone is scared of breaking or exploding these transaxles. The are the heaviest build tx out there aside from the cast iron case stuff and are built tougher than a lot of AVT transmissions. The only time I have ever seen one brake is one that was used as a gear box on a pulling sled. It snapped an axle when the chain got hung up, because it was being towed by a 100 HP pull back tractor.

I'm not afraid of braking it, I've run them pretty hard in stock form using implements and such. Just haven't run them with basically truck sized tires and locked is all.

It all depends how you lock it, flip the gears it's gonna break, with that much power and that big of tire, ive personally seen 3 broken with flipped gears on 25 inch tires. Weld it correctly and you won't have a problem.

I'm going to be trading my buddy my 4 pinion 633 for a 6 pinion 633 and I'm going to do the weld method to lock it this time. He's gonna put the 4 pinion of mine in an older suburban as a light trail machine/mudder with stockish sized tires. After my romp yesterday, im not concerned with turning radius on this machine vs straight line traction. Thanks for the opinions guys.