Tires 790+770 MFWD ratio and R4 tires

[irwin]

Did you fill the rear tires, Tim?

I just can't bring myself to do that Roy. I know the weight will help somethings, but I do so many different things with this machine. I'm concerned with damage to the rims with corrosion. I use a ballast box or have the backhoe on when moving dirt/rocks or stumps, but when driving through my woods, or across the lawn, I don't want it too heavy...so no tires aren't filled...yet

 

[BobT_770]

I entered this in another thread: I added 32 gallons of windshield washer fluid to each of the TUBES in my rear Turf tires (size 13.6 - 16)(225+ lbs each ) and it Totally changed my tractor for the better. I could not even back up in low range on a very slight downhill grade with FEL bucket full of wood without engaging 4WD. The benefit of solid (or filled) wheel weights and fluid-filled tires is these methods place no (or very little) additional stress on the rear axle.

 

[RoyJackson]

I just can't bring myself to do that Roy. I know the weight will help somethings, but I do so many different things with this machine. I'm concerned with damage to the rims with corrosion. I use a ballast box or have the backhoe on when moving dirt/rocks or stumps, but when driving through my woods, or across the lawn, I don't want it too heavy...so no tires aren't filled...yet

I like them filled for the added stability.
But I use the 790 for mowing, brush cutting and pushing snow (plus any other tasks we may come up with). I'll leave impressions on the lawn, but they're gone in a day or so. I do not mow or operate across the lawn when it's wet.
As far as corrosion...well, unless you use CaCl, I doubt if you'd have any problems.
There you go, Tim...keep us posted on how those tires work out!

 

[kennyd]

Irwin,
The link seems to be working now to the online manuals:
Operator's Manuals Results

 

[irwin]

Irwin,
The link seems to be working now to the online manuals:
Operator's Manuals Results

Thanks for remembering Kenny.
I do have a operators manual now, I'll order a service manual soon. I was hoping I could look at the repair manual for free

...tim

 

[kennyd]

I was hoping I could look at the repair manual for free

Yeah, RIGHT

 

[Radius118]

I am looking to do this to my 770. I have an extra set of turf wheels, but it looks like the rear tires in this link are discontinued. I searched for 110" circumference tires and came up with a large list but they all have different overall diameters. This should mean that the circumference will be different..

Any help with this? Perhaps you can post the exact size of rear tire you used?

Thanks,
Michael

hello Bob: no problem here ya go

Follow this for the rear tires... Titanｮ 2006 Tire catalog...and this for the front tires....Titanｮ 2006 Tire catalog...let me know if you have any problems..

edit: frt tire rolling diam. is 71"...rears are 110" . ratio is 1.549 this equals 1.4% lead on frts..

 

[irwin]

I am looking to do this to my 770. I have an extra set of turf wheels, but it looks like the rear tires in this link are discontinued. I searched for 110" circumference tires and came up with a large list but they all have different overall diameters. This should mean that the circumference will be different..

Any help with this? Perhaps you can post the exact size of rear tire you used?

Thanks,
Michael

Sure: 12.4-16 R4's .. I noticed titan no longer makes that size R4 but a call to your local big tire store might be able to help.

 

[Zebrafive]

I am looking to do this to my 770. I have an extra set of turf wheels, but it looks like the rear tires in this link are discontinued. I searched for 110" circumference tires and came up with a large list but they all have different overall diameters. This should mean that the circumference will be different..

Any help with this? Perhaps you can post the exact size of rear tire you used?

Thanks,
Michael

How much different were the diameters? They may have used loaded radius, which would be less than 1/2 of the diameter to compute the rolling circumference.

Using Irwin's ratio of 1.571 and 71" circumference front tires, you can use 107"-110" circumference rears and still have 1-4% front lead.

 

[Radius118]

Sure: 12.4-16 R4's .. I noticed titan no longer makes that size R4 but a call to your local big tire store might be able to help.

How much different were the diameters? They may have used loaded radius, which would be less than 1/2 of the diameter to compute the rolling circumference.

Using Irwin's ratio of 1.571 and 71" circumference front tires, you can use 107"-110" circumference rears and still have 1-4% front lead.

Thanks for the info. I ended up finding a good deal on a broken 1070 and I am going to convert that to R4 instead. I may or may not keep the 770 depending on funds but more than likely it will get sold.

In researching tires for my conversion, I have not been worrying about the axle ratios. The important part is the circumference ratio between the front and rear tires as far as the conversion goes. Using the specs I got for the OE R1 tires on the machine, I end up with a .599 ratio front to rear. The R4 tires I am looking at have a ratio of .623 with is about a 4% difference. That should be within the specs for the MFWD lead. I think.

Michael