Putting the wheel weights on the 646 has been a PITA. The most recent 130 lb. weights will fit over the 130 lb. combine weights. The two holes in them line up with two of the four bolt holes in the combine weights. So I chamfered two bolt heads in my lathe. Then Tig welded the bolts together. One side bolts the combine weight to the wheel and the other side bolts the two weights together. So far so good, but the new weights cover up the valve stem. So I ordered valve stem extensions from Amazon. A 45 degree extension on the valve stem and a 8” extension on that, to go through the wheel to the inside. Looking good but when trying to install the combine weights I damaged the valve stem extension because of very little clearance between the combine weight and the extension. After thinking this over awhile I came to the conclusion that that 45 degree extension was to high. Since it was broken anyway I decided to cut it down by 1/2” and silver braze it back together with a sleeve made out of small diameter copper tubing. Valve stem now is reinstalled but need to carefully install combine weights. I’ll keep you all updated dated as the project continues. Harry
I got a set of turf tread new take-offs that were from a Kubota tractor, and the rims on that set were standard backspacing. They are the 29 x 12.50s that I have been using on the rear of my loaders. I just have to make wheel spacers at 2 3/4" to move the tire and rim clear of the inner fender and the wheel drive motor. The standard rim of that size, I think, is in the center of the width of the rim. They are six bolts with the valve stem on the inside, like Case does, so that weights can be added without the issues you had to deal with.
ssmewing wrote: ↑Wed May 14, 2025 9:23 am
I got a set of turf tread new take-offs that were from a Kubota tractor, and the rims on that set were standard backspacing. They are the 29 x 12.50s that I have been using on the rear of my loaders. I just have to make wheel spacers at 2 3/4" to move the tire and rim clear of the inner fender and the wheel drive motor. The standard rim of that size, I think, is in the center of the width of the rim. They are six bolts with the valve stem on the inside, like Case does, so that weights can be added without the issues you had to deal with.
I had no problem with just the combine weights. The problem came up when adding the new weights that are like a cap that goes over the combine weights. When I was installing a tube in the rim I was thinking about plugging the original valve stem hole and drilling a new hole. I didn’t but then I acquired these other weights and now I wish I had. Hindsight 20/20. Harry
Harry wrote: ↑Thu May 15, 2025 8:36 am
I had no problem with just the combine weights. The problem came up when adding the new weights that are like a cap that goes over the combine weights. When I was installing a tube in the rim I was thinking about plugging the original valve stem hole and drilling a new hole. I didn’t but then I acquired these other weights and now I wish I had. Hindsight 20/20. Harry
Found time today to complete the weights, after many other things that pop up in a persons life. It was a bear getting the weights on without damaging the valve stem, but patience and persistence paid off. Much up and down with engine lift and a floor jack to get it in position. I weighed the cap weight on an old bathroom scale that I had in the shop. No idea how accurate it is but the cap weighed 120 lbs not 130 lbs. The other side still has liquid ballast in it so I didn’t add the cap weight over the combine weight. It will probably start leaking sooner or later and will need a tube also. Harry
Put the rear mowing deck on the 646 today and drove into the swamp to knockdown the high weeds. I noticed when hot and the pto on for the deck, the travel was slow even at high rpm. If I shut off the pto then even though hot the travel was much faster. Almost got stuck in some mud because the travel hydraulic pressure relief would open. I’ve been meaning to crank it up a bit but been procrastinating because it appears to be a PITA. Harry
After thinking this over awhile I came to the conclusion that that 45 degree extension was to high. Since it was broken anyway I decided to cut it down by 1/2” and silver braze it back together with a sleeve made out of small diameter copper tubing. Valve stem now is reinstalled but need to carefully install combine weights. I’ll keep you all updated dated as the project continues. 
Harry
