Tires 790 Front Tire inversion

RobS · Sep 10, 2003

<font color="blue"> When inverted the center "seam" of the front and rear tires are even. </font>

That's going to depend on the position of the rears isn't it? I never payed much attention to my fronts other than the valve stems are on the inside. If that means they're inverted I love it. If not, I still love it. Either way, that's how it was delivered to me from the dealer. I'll take a closer look tonight /forums/images/graemlins/smile.gif

F350Lawman · Sep 10, 2003

That's going to depend on the position of the rears isn't it?

I don't think anyone has there rears narrow on a 790. I don't even think my R-4s could be turned to the narrow setting without rubbing on something. Anyway, if you have R-4s they seams will line up when you invert the fronts to wide.

Mike_ONeill · Sep 10, 2003

I might be missing something here /forums/images/graemlins/confused.gif, but I need someone to explain how a tractor front axle provides any side-to-side stability. The axle is attached with a trunnion pin, and the tractor is completely free to hinge side-to-side about that pin. The front wheel spacing has nothing to do with it. The only time any side stability comes from the front axle is when the tractor has leaned sideways so far that the trunnion has run out of travel. i.e. the axle is hitting the stops. That is way too much lean for me.
It would seem to me that ALL of a tractor's side-to-side stability comes from the rear axle.
Someone please straighten me out.

JTC · Sep 10, 2003

Mike,

Depending on how you define stability, you may be technically correct. Since the back axle is solid, during a rollover event, the tractor will try to rotate around it's center of gravity with the front axle not contributing a counter moment to this rotation UNTIL the stop is reached.

After the front axle stop is reached, the rotation is opposed by the counter moment of the wheel on the ground. As with any level, the longer the arm the greater the mechanical advantage so a wider track most definitely makes a tractor more resistant to rollover.

So, if stability to you means "solid feel", then wider front track won't contribute to that since the angel the tractor is leaning would be the same. If stability to you means resistance to rollover, then front axle track is a significant factor.

Jim

F350Lawman · Sep 11, 2003

The only time any side stability comes from the front axle is when the tractor has leaned sideways so far that the trunnion has run out of travel. i.e. the axle is hitting the stops. That is way too much lean for me.

The paint is off the stops on my tratcor...someone must be leaning it. /forums/images/graemlins/grin.gif

I don't think it takes as much travel as you think, check out your stops , do they look untouched?

glalonde · Sep 16, 2003

I just got my 790 ~ a month ago. I'm brand new to the world of tractors.

Questions: After browsing multiple forums, I read that you can increase the spacing between the front tires for greater stability for using a FEL. I could never figure out how to do this.
This thread mentions to flip the front tires (i.e. valve pointing inside). Is this the only way the spacing can be increased i.e. all the talks on the other forums about increasing spacing ... was that always the only way ?

Guillaume

RobS · Sep 17, 2003

Guillaume, as you can read in this thread the front tire width can be changed, and it may affect the stability. The "how" is pretty easy. Just switch the LF and RF wheels on your tractor. Make sure the tread pattern faces the same direction as it does before the switch (that's why you swap the left and right). If you intend to do this, take a measurement before and after to share with the rest of us /forums/images/graemlins/smile.gif

F350Lawman · Oct 18, 2003

Well I think we finally have the definitive word on this. This is from the JD 419 loader manual. Since it refers in this book to the 790 and this loader is designed specifically for the tractor it should cover all possible safety and warranty issues.

They also have an illustration with a 790 and the wheels are set wide, you can see the axle flanges clearly. the (A) points to the centerline of the front tires.

419 Loader Manual OWM48833 ISSUE 2

Page 15-3

Setting Front Tread Width

Front tread width(A) should be set to the same tread width as the rear tires whenever possible.(See SELECTING TREAD WIDTH in this section)

Whiskey · Oct 20, 2003

flipped mine this weekend.....took all of maybe 20 min's. love it this way but it does seem to bite or cut more on sharp turns but, I don't mow the yard with this thing so I leaving it this way.

Whiskey