Turf tires & loaders

[WinterDeere]

Deere 855 (2000 lb. / 25 hp) with FEL on turf tires, used mostly on a well-manicured lawn in summer, and with a Woods SB64S snowblower in winter. Primary loader work is moving firewood, mulch, topsoil, and occasionally gravel. I often keep a 700 - 800 lb. ballast box on the 3-point when doing loader work, as I am often traveling a distance with a bucket full of material, and want to carry the maximum load the bucket can hold.

When I got the tractor, I immediately upgraded the front turf's to 6-ply (4-ply is standard), to handle the loader work. I did not have a user manual for the machine, so I just set the tires at 90% of their "max load = xxx @ yy PSI" rating, which amounted to 27 PSI front and 18 PSI rear. It worked great for my first half year with the tractor, and I'd been moving some fairly heavy stuff around in that time, although the ride was fairly hard.

Finally got the manual, and I see they call for "8 - 20 PSI" in the fronts (14 PSI median), and "6 - 20 PSI" in the rears (13 PSI median). The front rating is based on 4-ply, not the 6-ply tires I'm running. In any case, last night I lowered the tires to 14 and 13 PSI, respectively. The machine does ride nicer, especially going over bumps, roots, whatever. I was moving my snowblower around last night, and the squash out on the rear tires did not look bad, in fact not much worse than at the former 27 PSI. I didn't get the chance to really exercise the loader, though.

Where would you guys run your tire pressures, in this situation? Without other advice, I think I'd leave them at 14 and 13 PSI, until I see some need to raise them. I suspect the rears are good where they are, but anticipate I will need to raise the front pressures back up a bit, when I get into my next heavy loader project.

 

[art]

Air pressures are variable depending on the load you are carrying. The softer tire will give you a better ride as you have experienced. The harder tires will carry a load better but make the ride a little more challenging.
The one concern that I have is for axle wrap from possible tire pressure variations in four wheel drive. If the disengagement becomes difficult you might want to add a little pressure to the fronts to stop the squash.

 

[WinterDeere]

art,

Good point! I have noticed MFWD disengagement is sometimes difficult on this machine, and that was back when I was running 90% of max rated pressure on all tires. Since the problem was worse on hard surfaces or when turning (no surprise), I just settled for straightening the wheel and moving to a softer surface (or sometimes rocking FWD/REV a bit) to disengage MFWD.

There's likely an ideal ratio of tire pressures where the F/R ratio is perfectly matched, but it will always change with the load I'm carrying at that moment.