Depends on what you have to work with. I have changed out a clutch in one, in less that 2 hours. BUT, had blocking, chain hoist, transmission jack, lift chains, etc. etc. ready to go, plus used a small 3/8" butterfly impact to remove small bolts. Probably figure another hour to remove the flywheel, heat the ring gear with the acetylene torch, and remove, heat the new ring to put it on. Long guide studs to align the bell housing/torque tube, longer bolts to snug up after rolling ahead, to hold it in place, and engaging the pto once the driveshaft was to the clutch plate.Putting a crescent wrench on the pto shaft to align the splines. I'll have days like that where they seem to go back together too easy, then other days, I just have to walk away from it for a while, then things seem to go back as they should. But, I've worked on them for 40 years, and other models similar. The more you do, the easier it gets.
Main thing is, not to get in a hurry. Allow yourself all day, if you have the proper tools to do the job, and the first time splitting a tractor. Taking them apart is the easy part, going back together, can be a different story. If it's the first time, doesn't hurt to take pictures to have something for reference. And torque everything to specs.
Ummm..., no, that's just how long it took me to work on my own tractor, in my own shop, considered my "dream shop". I'm now in dream shop 2, smaller, but pretty much same amenities, and a few more goodies to work with to make life easier.Is that the flat rate book time? Thanks.