Tires YM336D Turfs vs Ag Tires

roger_scotty · May 28, 2003

OK, it has been a year since putting the big ol' turf tires on the YM336D - and I've now had enough experience with them to make some observations. There are pictures attached here of the tractor with both tire sets. Yep, the turf wheels are JD yellow. Those ultra wide turfs were a factory option for both the Yanmar 336D and the JD 1050, and the used ones I found came from a JD 1050. Absolutely identical to the Yanmar ones except for color....right down to having the same part number on the rim. Someday I'll paint them....
BTW, those super fatty turfs were a fairly rare option on either tractor. Like I said, I found a used set and I'd tell you what I paid except that I'm embarassed to say how much. But they were not cheap.
1. Traction. The stock Ags have quite a bit more traction in soft dirt, soft snow, and a bit more in on hard snow. Neither tire is much good on hard packed snow without chains. On hard packed dirt the turfs have a little more push. All in all, about what one would expect.
2. The turfs and pushing the front end out on corners.... Those fat turfs on the front will tear up a lawn in no time at all if you try to turn sharply on wet grass or sod. If you turn less sharply they will still tear it up....it just takes longer. Take my word for it.....the super wide turfs are definitely not recommended for lawns. Of course the Ags aren't all that much better. Luckily Yanmar also offered a narrow diamond tread golf course turf tire that would fit on the standard ag rims. That would have to be the tire of choice for lawn work.
3. The turfs are much more stable on side slopes. Not only is the CG a few inches lower, but the whole tractor is wider and heavier at the corners. Now I can turn across a slope when going downhill with a modest load in the bucket.....something that I wouldn't even consider with the Ag tires because of my "chicken factor".
4. The turfs are more comfortable. Lots more comfortable. They give a softer ride and they don't make that "thump-lurch" that the front ag tires do when turning a corner.
5. Which do I prefer? Well, I don't have much of a lawn...and my dry land is very steep. Its the turfs and stability for me. I'll build a set of chains for the snow.

BrettW · May 28, 2003

Roger, the pic on the right is just regular rice tires? thanks for the post and I recommend painting the entire tractor Yellow instead of going to the trouble of working on the wheels. /forums/images/graemlins/laugh.gif, bw

roger_scotty · May 29, 2003

The tractor on the right IS the tractor on the left....Its the same tractor with two different tire/wheel sets. Say, in that photo those do look like rice tires don't they? Must be the angle or something because the tires are the std. Ag tires offered on the later YM336D. The rears shown in the right hand picture are Firestone 13.6x26 having tread type: Firestone All Traction Field and Road. The fronts are Ohtsu 8x16 Ag type, not rice......though every time I look at the picture again they look like rice tires to me too!
Or I could do like Yanmar did.....Change the model number to read JDxxxx, leave the wheels yellow, and paint the tractor green. I kind of like the yellow wheels with the red paint, but my wife took one look at it and declared that I had ruined the elegant Yanmar color scheme.
Everybody wants to be an art director.... /forums/images/graemlins/shocked.gif

Anonymous Poster · May 29, 2003

Roger:

What size turf tires are on the back of your 336D? I have a FX28D that I am trying to get turf tires for. It came with 12.4-26 All Traction Field and Road on the rear and 8-16 on the front.

Doc

roger_scotty · Jun 9, 2003

Doc, those enormous rear tires on mine are 44x18.00-20NH. Switching over to them required that the wheels be changed as well. But there is more......

Yanmar offered two turf tires options for the 336D. And it might be something to think about for your FX28D (Nice Tractor!). What I call the "medium turf" option was what is locally known as a balloon style diamond tread tire and it fitted on the standard rim. Much the same size as the ag tire...maybe a touch fatter.... but instead of lugs it has shallow diamond shaped tread. I see that type of tire golf course equipment and in old Yanmar advertisements. There was a matching front as well.

Option #2 was what I found for my YM336D. This might be called the Extreme turf setup and requires replacing the wheels as well. I wanted it for the large increase in sidehill stability that it gives me....and it has fit the bill. For use on lawn the extreme turf tire is a disappointment because it doesn't want to turn sharply without plowing up the turf with the front wheels. The extreme turf tires are a bit pricey, too.

Do you know your front-to-rear gear ratio? That is where to start with any tire conversion. It is easy to measure, and then with that information and a pocket calculator we can go to the tire manufacturer spec sheets and choose from several pairs of tires. We want to match the fronts to the rears tires using the tire mfg spec for "Loaded or Rolling Circumference". The object is to match the new tire pair to your existing final drive gear ratio.