Tire and rim change on a Kubota M9960

[KubotaM9960D]

Hi guys,
In the fall I bought a Kubota M9960 off an auction. It has 18.4x28 tires on it the rear, but I would like to put narrower tires and rims on it. I would like to put 15.5x38 tires on it with a spacing of about 72'' on center of the tread. I was wondering if you guys have either done this or if you know of a reason that it wouldn't work.
Thanks

 

[5030]

So long as you maintain the correct 'lead lag' ratio, you can change anything. Screw up the lead lag ratio and you'll destroy the front drive...if it's front wheel assist that is. If not, don't matter.

 

[Farmer495]

Hi guys,
In the fall I bought a Kubota M9960 off an auction. It has 18.4x28 tires on it the rear, but I would like to put narrower tires and rims on it. I would like to put 15.5x38 tires on it with a spacing of about 72'' on center of the tread. I was wondering if you guys have either done this or if you know of a reason that it wouldn't work.
Thanks

If 2wd no major issues, just need the right wheels/rims and measure the make sure you have fender clearances.

If 4wd, you have to match your front axle lead or you will destroy something. compare the RCI (rolling circumference index) of the two you have with the one you.

 

[oosik]

I'm surprised. Didn't your 9960 come with Ag rims. If so - they are completely adjustable to just about any spacing.

 

[5030]

The 9 series all have adjustable rims (front and rear standar)d but he wants to change the tire diameter which will require a rim change so the 'lead-lag' ratio comes into play.

Considering what new tractor tires cost today, rims not withstanding, if it was me, I'd be running what is on it. Just replaced all 4 on one of my M9's and 4 new radials set me back over 5500 bucks.

 

[oosik]

I completely agree - 5030. Surely with the Ag rims - he can find a width that will satisfy his needs. However - lets see what he says when he finds the price of new tires AND rims.

A word of advice to the OP. I wouldn't consider "cheap O" rims or tires. Your 9960 is a big tractor and could easily damage cheap stuff.

 

[LouNY]

I'm guessing he wants to do some row crop work and the 18.4 is too wide and the 15.5's will fit his rows better.
If his tractor is 4wd he will be needing to change his front tire sizing also. The 15.5x38 has a 2" larger loaded radius compared to the 18.4x28.

 

[oosik]

I just had an idea. I wonder if the OP can change the spacing on his row crop to match up with one of the settings on his current tires. His operators manual will show that there is eight different setting for wheel spacing.

 

[5030]

Expensive alteration far as tires and rims are concerned.

 

[KubotaM9960D]

Thanks guys for your responses!
LouNY is right, I do want to do row crop work. I work on a smaller vegetable farm in MA and changing the spacing of our crops is not an option. And I know that new tires and rims will be very expensive, I was just trying to find out if this would work. What do you think the front tire size should be if the rears are 15.5x38 to keep the ratio right?
Thanks