i worked all afternoon getting a krause 12.5 foot offset disk hooked and adjusted to the D46U.  the disk is heavy with 8 inch spaced and will try it in sandy loam and sand.  what gear do you think i should use?  will it pull it????
Thanks.      pics to follow

well i would start with first gear and the work my way up.

thanks. yes i can start in first gear but with disking there is a speed component also in order to turn the soil. according to the disk manual optimum would be 4 to 6 mph.

Depends on blade diameter too, should pull it in third gear, around 3 mph.

blade diameter is 22 inches cupped not coned disks. i am hoping 3rd will work.

speed also depends on the soil condition hard dry soil wont till like soft damp soil. is it clay based or peaty soil is it volcanic . really the ideal speed is what the machine will pull it at and give the desired result. working depth has a lot to do with it too.

That is a lot of disc for a D46u, but as said above, depends on the soil. We pull a 10foot JD disc with a D4C in hard adobe, neighbor pulls 8ft with D47U, but that is HARD adove clay soil, do you may be in luck. Send pics if you can be nice to see your tractor working.

The 9 and 3/4 or 10 and 1/2 foot heavy 9 inch spacing disc was the norm behind a u series D4 in my hilly country. More rolling a few pulled 12 foot discs. I have 16 foot 7 inch spaced disc that was used in lite soil or in clean up of summer fallow that was used behind a D4. But does a very poor job as primary tillage in most soils here. With the rock that is farmed over speed was never looked on with favor. But with hills had to be able to go up most anything in first, so on level you could use a higher gear. The highest was only used between fields never a working gear. As some put it the going to the fire gear.