Tiller Conversion for B6000 PTO

This is a G4000 tiller that was made for G4000 and G5000 Garden Tractors with the CAT-0 3PH. I found a manual to go with it and realized that the drive could be flipped over from a CW PTO to CCW PTO like on a B6000. Needed to convert the 31/32" 10 spline PTO shaft to a common 6 spline 6N drive shaft coupling, some holes for the CAT-1 top link, and bush the lower pins up for a CAT-1. The right angle gear box had to be flipped over, and then the chain case had to be split so the shaft on the chain case drive sproket came out on the left hand side instead of the factory right hand side. The mount for the gear box required relocation to reset the pinion angle and to maintain the chain alignment, as it was offset 1" from center at the factory. The biggest headache on this was trying to split the chain case because the tine shaft inner bearing race was rusted siezed onto the tine shaft it had to chizeled off in small chunks. A torch and hammer would not get it free. Also these self alining bearing housing called flangette halfs that hold the bearing in the chain case are no longer available from Kubota, so don't beat them up to bad when your trying to pry off the tine shaft bearings. The new tine shaft bearing was available from Kubota, and the 10 days it took to get it was the biggest set back on this project. The resulting performance is leaving something to be desired, as the tiller has a tag for a 2000 RPM PTO, and the B6000 runs only up to 1350 RPM. It still gets the job done, just would be more efficient with a new smaller rear sproket turning the input on the chain case. Maybe that will be done next year along with a new chain gaurd. Seems to work better backing up than going foward. If I could do it again, I'd just swapped the side the tines were on and called it a day. It may have ever worked better!

I guess if I knew the true meaning of reverse rotation tiller was before I undid the opportunity on this one, I certainly wouldn't have. Maybe there is a lesson for some others to take away from this project. B6000's can run a CW rotation tiller better than the other guys, just swap the sides on the tines. Now if I can just make sure I don't install my next new battery backwards... Sometimes things are more obvious only after you figure out what you did wrong.

Recently replaced the primary chain set driven sproket. A 27tooth replaced the stock 40tooth. This thing now DIGGS! The issue I found was that the G4000 was made for a 2000rpm tractor PTO. With the B6000 only turning 1350rpm, this thing was over reduced, resulting in too few tine rpm. The sproket swap was easy, only had to drop 4 links from the chain. Overall, a gear change on this tiller would be necessary swap if anyone else plans to run one on a B6000. New sprocket from the Big Bearing Supply Store (online) $30 with shipping.

In order for you to know how to correct the gear reduction, you need to know a few things. 1. Your tractor output PTO rpm (540), and 2. the attachment recommended input PTO rpm (2,000).

With this information on hand, you then need to open up the tiller or pull off the gaurds to find what you can change to speed up the final drive. Get the tooth count on both the sprokets, as you may be able to drop teeth on one, or add to the other, or a combination on the two if you have to make up or drop a lot of speed. In checking the sprockets, you'll need the chain size, and the shaft size, and check what size key stock is in the shaft. Check the face offsets also, athough you may be able to work around this one. Take a look at the technical information available from your sprocket supplier, or your local Tractor Supply Store. The literature will help you determine what size you have, and what replacements are available.

I'm not a power transmission engineer, so I don't know if my math is good, but this worked OK for my project. If you use the following calculations, your on your own.

To make up the speed on the driven sproket 540/2000 x N teeth on the stock sproket. Smaller driven sproket is going to spin the secondary drive faster. (40T stock, replace with 11T) I'd try this first, this is a big step, so the chain tensioner is gonna be a project to get to work.

To make up the speed on the drive sproket 2000/540 x N teeth on the stock sproket. Larger drive sproket is going to spin the driven sproket faster, and with it spin the secondary drive faster. (12T stock, replace with 44T) I didn't mess around on this one, the slip clutch was mounted to it, so I just stayed away.

I hope this helps you, but again your on your own, its your project!

Anything is possible, if you have enough determination. However, first searching for the simple solution is a wise choice. I could have bought a reverser box, somehow, someplace....But that would have cost more than the tiller! I later learned that the gear box could have been reversed by swapping the side of contact in the 90deg box, buy swapping a gear from left to right side contact on the pinion. That sure would have saved a pile of work on the moving of the chain case. Anyway, this works well for what I do with it. Reducing the gear reduction in the primary chain seemed to have made all the difference.