Gear ratio

Anonymous Poster · May 20, 2003

Does anyone know the front/rear gear ratio on 1500D. I'm doing some research on the Goodyear web site as far as finding the correct front to rear tire sizes to keep everything from winding up due to improper tire sizes for 4WD.

There is an easy formula to use if you have that ratio. They say typicly it is between 1.2 and 1.5. Thanks

Anonymous Poster · May 20, 2003

You can look up your current tires rolling circumference on the manufacturer's web site. The ratio of rolling circumference is what you want to maintain. Generally a lead of 2% (front tires going 2% faster than rear) is what is shot for. 0-5% is acceptable, No lag is acceptable.

normde2001 · May 20, 2003

Jack up one side and measure the circumference around a front and rear tire in inches. Divide the rear by the front, Assuming you have it correct now.

kayssupply · May 20, 2003

Are you not going back with OEM tires?

Anonymous Poster · May 21, 2003

First, the rolling circumference listed on web sites is useless, at least on Goodyears site. Why? Because of the way they determine it. The circumference is measured with the tire at "rated load", and "rated psi". Well, the psi part is a no brainer, but the loaded part will never work unless you have a set of scales.

If they say the R/C is 100 inches at a loaded rate of 1570#, how the hell are you gonna know if you have 1570# on each tire? Goodyear techs say to get the actual circumference by using diameter x pie (3.1416) to find the proper front/rear ratio.

Second, as far as OEM tires. I'm keeping the rice tires on the original rims for certain situations. But I got some good info from a dealer in Ohio about the rear rims. Mid 80's 1/2ton Chevy 4x4 pickup wheels have the same bolt pattern as the rear of a 1500D and are 16inch. The bolt holes must be drilled out to 5/8 but he says they will work, however I have not varified this yet. Get two of them with some 16inch turfs, the right size car tires in front and you should be ready to go.

LLove · May 22, 2003

I've tried the 6 lug Chevy/ Gmc wheels on my 155d... using the 4wd version. The bolt circle diameter was too small, figured that I could slot them.
But closer inspection showed that the OEM wheels are piloted by the Center Hole onto the axle adapter Hub, not by way of the Lug Bolts. Drilling the holes oversize would work also as long as the Rim center hole fit the tractor Hub as good as the OEM rim does.
The rims I tried had way too large of a center hole for my application. I didn't want to place all of the load onto the Lug bolts since Yanmar had seen fit not to do so either.
HTH , keep us informed of what you come up with!
Lloyd