Gator XUV 26" Tires on rear with 25" on front

454shooter · Dec 22, 2010

As a follow up to a below post: I ordered 26" Maxxis Bighorns to replace my factory 25" Carlisle 489s for the rears of my 2008 850D. I planned on leaving the 25" factory 489s on the front. There is an approx. 3/4" difference in heigth. (I wanted more ground clearance since I was forced to change a tore tire and didn't want to buy new rims)

I am taking a lot of flack at work that this is a dumb idea as the 4x4 system will be damaged by this. Has anyone else done this?

Will the 3/4" difference hurt the 4x4 drive system? I figure it would be slipping anyway if the 4x4 kicks in so it shouldn't matter but now am having doubts and am thinking about ordering new front tires also. The factory 25" ones are like new.

If I do order new it looks as though the Bighorns in a 12" rim 26" come in 9, 11 and 12" wide but my factory rim has a 10" wide tire so I guess I should go with the 11" wide. Sound correct?

KentT · Dec 22, 2010

454shooter said:
As a follow up to a below post: I ordered 26" Maxxis Bighorns to replace my factory 25" Carlisle 489s for the rears of my 2008 850D. I planned on leaving the 25" factory 489s on the front. There is an approx. 3/4" difference in heigth. (I wanted more ground clearance since I was forced to change a tore tire and didn't want to buy new rims)

I am taking a lot of flack at work that this is a dumb idea as the 4x4 system will be damaged by this. Has anyone else done this?

Will the 3/4" difference hurt the 4x4 drive system? I figure it would be slipping anyway if the 4x4 kicks in so it shouldn't matter but now am having doubts and am thinking about ordering new front tires also. The factory 25" ones are like new.

If I do order new it looks as though the Bighorns in a 12" rim 26" come in 9, 11 and 12" wide but my factory rim has a 10" wide tire so I guess I should go with the 11" wide. Sound correct?

Your co-workers are correct. The front and rear tires should have the same height/circumference, though they can be different widths. There is no way for the front axle to turn at a different speed than the rear. Something has to give... either the tires spin (without traction) or mechanical breakage (with traction)...

I'm running 26x9x12 Bighorns on the front of my Rhino 450 and 26x12x12 on the rear. I would NOT recommend the 11" or wider front tire, unless you have power steering. It would be very hard to steer it at low speeds and almost impossible to steer it sitting still. Never seen the 26x11s that I know of, but the 26x12s are some big, beefy things...

I know a lot of folks that run 26x9 tires on all four wheels so they can rotate the tires...

2fast2 · Dec 22, 2010

My understanding is that the Gator XUV is a mechanical four wheel drive system like many MFD tractors. There is no differential between the front and rear drives, no viscous coupling, nothing to "give" for that 2 3/8 inch difference in travel with every wheel revolution. Something would have to give and that is a lot of slippage. Unless you're on ice or snow or slick mud when you engage and try to disengage the 4wd system, I think the mechanical wind-up would cause damage.
I recently changed tire sizes on my JD 5210 MFD tractor. The owner's manual provided a chart spelling out which size front tires were necessary to correspond with the different rear size options for the tractor. The Gator's manual doesn't offer such a chart because I don't think Deere anticipates that owners will want to change tire size. When you do, you change gearing and power output (and speed) although these might be minor considerations for you given the small change in diameter you cite.
The final answer would be from the Deere engineers. Did you try contacting somebody at JD for the official "right answer?"
My recommendation is to buy the fronts to match the rears and sell your old ones on ebay.
Good luck.