question about wheel spacers to increase width of tractor

[sixdogs]

Widening the rears, even 1.5" on each rear tire makes an incredible different in perceived stability. ...

Yes it does.
I recently narrowed my JD 5520 from a 63.4" rear tread (center line to center line) to 60.4 inches and I am shocked at the difference in handling characteristics on an 8,000 lb tractor on flat ground . Now, I have 18.4 by 30 rears and 12.4 by 24 fronts with lots of weight so that three inches makes a world of difference and I'm on flat plains ground. It would make me uncomfortable if I were on hills. So I could easily see that adding a few inches to a smaller tractor would greatly enhance stability.

[rbtjr]

I have a FEL with a 62" bucket, so if I move the rear wheels out from the current 60" to 66" outside-to-outside the wheels will be 2" wider on each side than the bucket width. I will be glad to live with that in order to get the additional stability.

[sdkubota]

You will be happily surprised at the difference. If you are adjusting kubota hubs...I had to swap the tires from side to side because my inner hubs were set in and I set them out (if that makes any sense). The other thing I was nervous about was my rear wheels were filled with fluid and I was alone. I just kept the wheels upright at all times when swapping and everything went easy peasy.

[sixdogs]

I have a FEL with a 62" bucket, so if I move the rear wheels out from the current 60" to 66" outside-to-outside the wheels will be 2" wider on each side than the bucket width. I will be glad to live with that in order to get the additional stability.

I would guess that moving the rears out is far more important than moving the front out. Seems to me that a wider front and narrower rear could actually decrease stability and create a tipping situation but that's just an educated guess.

[Rhino35]

There are tradeoffs with everything. Widening the rears 6" will make a considerable difference in stability and will put more strain on the rear axle but probably within design parameters. The other issue to take into consideration is if you have an FEL attached...you don't want the rears much wider than the loader and ideally should be the same. My kubota L3400 has its rear wheels set at their widest possible factory setting and I am 4" wider in the rear then the loader width. It is much more stable as I nearly tipped the tractor day two of ownership. Bottom line is small tractors are tippy with a narrow width and center of gravity fairly high. The more you operate it the better feel you will have for its limitations.

Hello Everyone,

I signed up when I was ordering a Kioti CK35, but I wound up getting a Kioti DK SE 40 hydrostatic. Mostly because so many guys here thought the DK SE 40 was the "value point" in the Kioti lineup. It is an amazing tractor to my neophyte eyes. I am a Tractorman Novice, only just self-promoted from Tractorman Fool. Reading the manual cover to cover before setting foot on the tractor seemed like a good way to get myself promoted from Fool. So I've had this beast two weeks and I just finished three afternoons of bush hogging 8 very hilly acres. I mean hilly here in Northern Kentucky! I went up and down the hills, backing and then going forward both ways up and down depending on where I needed to poke the bush hog into the forest, and rarely had the gumption to try any sidehill work. Of course you do wind up going sideways to turn around and frankly, it scared the **** out of me almost every time the tractor wasn't pretty much level. It is a very disconcerting feeling! Seat belt on and ROP up and "how far can this thing go before it suddenly rolls over!". The scariest part was not knowing where the little ravines and depressions were under the vegetation. I always went very very slow, which was necessary anyway because the Kentucky Jungle vegetation was very dense anyway. My tractor has an FEL, which I kept so low I accidentally dug up dirt when going forward a few times after switching from going backwards. My rear tires are loaded with Rim Guard and weigh about 600 pounds each. I have the widest possible factory setting for the rear wheels on Industrial Titan R4 tires and the front wheels, as I understand it, are already set to a factory wide spacing with R4's.

So I'm very interested in investing in wheel spacers. Great discussion about the utility of doing the rears and the less desirable option of doing the fronts. I am not going to be using this tractor for heavy FEL work - might lift 500 or maybe 1,000 pounds once in a great while - and the FEL is certified to lift 2,700 pounds. Just messing around lifting a tree limb or rock, some topsoil or mulch. Given that kind of forecast lighter duty, would anyone be worried about the extra strain on the front axle some have mentioned? And even if the front axle pivots, I don't see why wider spaced front tires wouldn't add to the overall stability and help keep the tractor from rolling sideways. The comment above about not having the rear wheels wider than the bucket - what is the reasoning behind that caution? My dealer said that in an FEL tip over typically one rear wheel will raise up as the opposite front wheel goes down into a depression and this tip over danger is heightened with the FEL raised. If the opposite rear tire in this tipover scenario is wider than stock wouldn't it be an even better balance distance from its opposing front wheel? Or does a spacer, say a four inch one on each rear wheel, move the tractor's CG forward and therefore make the tractor a little more "short coupled", where it might twist around when it tipped forward?

Some really great experience here on the forum. I've been lurking for months. Thanks in advance for any replies.

Best,

Rhino

[sdkubota]

The rear width comment has to do with digging a trench or similar activities. If you rear whell sticks out farther than the bucket you will rub the wheels. Sticking out a few inches also invites things to wack you or stick in the tires. I have never seen a loader, skidsteer, etc. that had a wheelbase wider than the bucket. That was the only reason for my previous comment. I would not widen a front end and believe it will results in damage to your axle or front drive.

[MHarryE]

The attached link will show how wheel bearings are intended to be loaded. Shift the tire to the outside and the outer bearing sees higher load and the inner bearing is unloaded. If you are interested in the life calculation including side loads, etc., SKF has an excellent web site. The net result is, however, that wheel spacers really load up the outer bearing. It's why manufacturer's don't usually recommend them unless it is part of their design.


http://static.ddmcdn.com/gif/bearing-wheel.jpg

[Rhino35]

SD,

That makes perfect sense for FEL work - thanks.

I appreciate the advice not to widen the front end too.

Rhino

[Rhino35]

Harry and All,

I just poked around the internet looking for more information about wheel bearings. I found several car forums where the subject was discussed. As SD and others pointed out widening the front tires, which steer, is more problematic. For cars effects can range from tire scrub to loss of traction to larger turning radius' to the bumps in the road translating into steering wheel twitchiness. I would think that most of these effects would be lessened by the slow speeds of tractors, but then again my manual is full of cautions about going fast on pavement and turning sharply. I think it wise to leave the front tires stock, but I am still interested in the question of the rears. All the articles agree with you that there is increased stress, wear and likely premature failure of the wheel bearings if you add spacers. The question is over what time frame? We measure our tractor use in hours. And what is the cost of buying new rear wheel bearings versus the benefit of greater stability and safety on hillsides? I found an article on how to detect wheel bearing wear, but the bottom line is it can be hard to see as wear is measured in very small units. For fast moving machinery where heat buildup might lead to catastrophic failure an in-service failure would be bad. For our slow moving rear tractor wheels an imminent bearing failure might be squealing, or odd ride, or a drag from the less than optimal friction. Has anyone ever experienced a rear wheel bearing failure in a tractor? I wonder - could a rear tire actually fall off? That would not be good!

I found an online Kioti parts catalog that had the front wheel bearings priced at $46 each. Couldn't find the rear wheel bearings (anyone?), but I'd imagine they would be more expensive. Let's say they cost $100 each for argument's sake. Plus labor to install them, which in my case would be $75 to have the tractor taken to my dealership plus perhaps $200 labor to pull the 600 pound rear tires off and remove and replace the wheel bearings. That would be $375. Not insignificant.

The big question...how often to schedule the replacement to preclude an in the field failure? It sounds like a fair number of tractor owners have spaced their rear wheels. Any real world experience? One car forum guy noted the discussion of physics but said he'd driven over a hundred thousand miles in a ferrari at very high speeds and had not problem with the spacers he'd put on this car. Hmmmm....now there is where a catastrophic failure would be noticeable!

Thanks for any and all opinions or real world commentary.

Rhino

[MHarryE]

Not tractor but combines which have separate final drives but same principal - axle extending outside to a flange, like most of the smaller tractors. When I worked at Case IH (1990 - 1992) a problem was people making their own bin extensions. Our final drives were not particularly robust. In fact our combine, an older Case IH rotary, has a decal on the cab sidewall stating that with a 6 row corn head the bin limit is xxx, with an 8 row corn head the limit is you, etc. It gives different capacity limits for wheat because of the heavier weight per bushel. It's all pointless because how is a person to know when they have 183 bushel in their 210 bushel bin. But -- with customers putting extensions on an already marginal final drive, we got to see many pictures of outer bearing failures. The combine would be leaning to the failed side. If it was the left side the walkway might be pushed up when the bearing failed. Worst case I can remember is a customer installing duals (not allowed) and then driving down a gravel road holding to the right as far as possible which put the outer dual on the grader windrow. Something like 2 miles when the bearing failed and he spun into the ditch. Too bad we didn't have digital pics in those days - I only got to read the accident report and look at the pics before initialing and sending them on. But usually you will see oil dripping out before it reaches this state. Once the bearing has a catastrophic failure the housing is so badly damaged it needs to be replaced. In those days Case IH was super cheap. We engineering managers had to have senior Vice President approval before we could introduce any change that added cost, and I do mean even one cent. So you can imagine what resistance a robust final drive would have met. But I digress - the question was whether or not anyone has seen or experienced one. Not personally experienced, but many dealer reports with pictures and swear words at the stupid engineers.