Looking at the M4800SU and it lists rear tread width at 51.9-67.7. Where is the variation coming from since the dealer told us the wheels were not adjustable. Is it tire type?
If it is like my M6800 you can turn the inside hubs in or out and also the wheels in or out to get a lot of different widths. That was the first thing I done on my tractor to widen it out.
Yup,
Like the other guys said, you should be able to dish the hubs and wheels in or out giving you 4 different widths. (at least with the R1 AG tire/wheel combination)
There is also a difference of width depending on whether you have R1/R3/R4 - tire/wheel combinations. I don't know if the R3 turf or R4 industrials allow you to invert the hub/rim for width adjustment.