Tires L5030, increase stability by widening front end tires??? Not sure, difficulties found

[texasjohn]

Been doing lots of work on slopes lately...digging out a dirt stock tank.
Decided that everybody says to widen front end stance just make sure tires/rims are set so they dish "out, not in." Might be a good idea to do it now.
Feeling that I would benefit from a improvement in stance, thus safety, I stated down this path.

1. Rear tires are already at max width...good
2. Front tires are narrow, dished in...candidate for widening
3. But wait, I looked into this when I first got the tractor and something stopped me..what?
4. Check WSM, clear instructions for rear tires and front of 2wd .... ambiguous re 4wd
5. Decided to call dealer I got the RTV from. Service manager said..can't recall your exact model, but we do it all the time. Swap right and left tires, putting valve stem inside (some people don't like this, but it's OK for me). Also, use washers and turn the nuts around so the cone is facing out.
6. Dismounted tires, not big deal, FEL lifts tires off ground, impact wrench handles lug nuts.
7. Mount first tire reversed with washers and reversed nuts. Sure enough, it'll give me about 2 more inches width, eyeball measurement...whee!
8. Spin tire in jubilation...CLUNK...it hangs and doesn't spin.
9. Rats, valve stem protective shield is hitting, just barely, on axle frame.
10. No problem, I can see if I cut 1/4 inch or so off the metal shield, it'll pass the protruding bolt head. I have metal cutting tools...done for both rims...whee!
11. Remount tire, check to insure that metal shield now passes the protruding bolt head...yep, bout 1/4 inch...good enough...once bolted tight, relationship remains fixed as tire rotates.
12. Spin tire in jubilation...CLUNK...now the valve stem, itself, hangs, just barely, on another part, by about 1/4 inch. Can't cut the stem, can't cut the part, need shorter stem.
13. Studied on the net and discovered that a shorter integrated stem and valve can be had
14. So, Sat morning, headed to local hardware store to see if they might have stem...arriving in town, saw local tire company, normally closed on Sat, had son of owner locking front door. Stopped and asked if he could help. He did have two of the shorter stems, pointed out that I'd have to break tire down and remove old stem, insert new. Wonderful small town where you can still get personal service!!
15. No problem, I have a HF tire changer, bunches of tire irons, and am of an age where "I know how to get things done," as they say in the TV ad:laughing:
16. Broke tire down, but fumble fingers pushed old stem into tire without catching it...now it's rattling around inside.
17. No problem, I got new stem and can insert and worst case just let old one rattle around.
18. AGAIN, fumble fingers lost NEW stem inside tire.
19. Insert second new stem, this time successfully.
20. Spend 30 minutes seeking to retrieve two lost stems...sidewall of tire is MUCH STIFFER than regular car/truck tire...lots of sweat, no success, can't get inside or even see the stems...if I could, I have finger grabber and could get it ...oh, well, lemme try it.
21. Remount tire reversed and spin again to see how it works....CLUNK...oh, yes, opposite tire still has problem.
22. Carefully check, yes, shorter stem DOES pass so now all clear on ONE tire.
23. But, tire store is closed, 40 mile round trip to next town would get me another stem and would still have 2 stems lost inside a tire...it's just gotta be broken down by hydraulic tire changer.
24. Think about it a minute....decide that it's a tractor free weekend....will take both tires to local tire shop first thing Monday, let them do it without me breaking a sweat, again. Sometimes, it's just best to leave it to those who are well equipped:drink: and enjoy the weekend.

Given all the above...assuming that tires are reversed successfully and no more hitting of valve cover or stem, DOES ANYONE KNOW OF A SPECIFIC REASON TO NOT REVERSE THE TIRES??? I can see no reason that axles or gears would suffer additional stress or other problems...do you?

 

[KennyV]

Yes....
Don't do it for the reason most folks don't.
1....It will give you zero additional stability. (The front axle housing is on a Pivot, hence zero increase in stability.)
2... It will increase the stress on the front axle stub, wheel bearing and seals.
3.... It will change the turning track and that Also increases the load on axle stubs, seals and all steering gear.
4.... . WSM will tell you Not to reverse the rims on the front.
5...If you search this, or most any other tractor site, you will come up with this same information including pictures of the eventual damage that it will cause.

Put them back the way they should be, especially the lug nuts... And don't leave the stuff rolling around inside the tires, it will eventually abrade the inner membrane and you will have slow leaks....

 

[kuboman]

Must agree with KennyV. Also the bevel on the lug nut is there for a reason otherwise they would just use ordinary nuts for lug nuts.

 

[vtsnowedin]

I have to disagree with KennyV!
A tractor reaches the tipping point of no return when it's center of gravity moves past the plane formed by the line drawn between the center of the front and rear wheel track projected vertically. Moving the front or rear tire ,or both, out moves this plane away from the COG of the tractor and increases the angle the tractor can be tipped before crossing this point. The front pivot dose have an adverse effect when one front tire drops into a hole on the low side as it moves this plane line in towards the tractors COG but a wider stance is also better in that case. As to the increased stress issues they are there but well within the working limits of the parts and much less then the stress of carrying a full bucket of heavy material down a rough road at speed. If your tractor is that close to it's working limits then perhaps you need a larger tractor or one of a different brand. :2cents:

 

[texasjohn]

Right, parts will clearly not be rolling around when all is said and done.

Specific stability issue is when turning downhill, front tire in direction of turn comes in under vehicle and results in more tippiness, seems that a wider front stance will reduce this tippiness somewhat along the lines discussed by vtsnowen. Maybe not a lot, I believe that after parts are removed I'll be able to mount them, reversed and do a little work...I think I'll be able to tell the difference if it exists, maybe not...we'll see. Agree regarding axle pivot.

Regarding strain increases...yes, gotta be some additional there since the geometry has changed, I can see that. Guess it boils down to the design limits of the parts. I haven't tried any math, but am guessing that the increase would be on the order of 10% more, certainly less than 50% more. I would hope that Kubota's engineering point is not that close to the edge.

I can see that the turning radius will change, slightly larger I think....will have to see if experience makes this apparent.

Net, on Monday the hidden parts will be retrieved. I also intend to call another dealer whom I have used and trust and see what they say...will let all know what I hear from them...and will give it a short trial. Depending on all input and experience of the trial period, I'll decide which way to go. And, it could well be to go back to the way it was.

Thanks for all input...

 

[David_Kb7uns]

I have seen the M series with reversible wheels and they have a lot heavier front axle the Grand L series manuals specificly advise against it and have seen pictures of the results and they are not pretty.

David Kb7uns

 

[Sawdustsmb]

KennyV is correct - no additional stability - and you cut on your tractor for only 4 additional inches?!

 

[vtsnowedin]

Perhaps reading this will help the undecided.
http://www.nstmop.psu.edu/tasksheets/4.12 Tractor Stability.pdf

 

[kuboman]

I agree that a wider front end aids in stability but the extra stress on the front components is exponential. Just observe the arc the the front wheel travels as you turn the wheels. The farther you move the wheel beyond the pivot point the higher the stresses. No loader, no problem, but with a loader you will be replacing parts.

 

[SPYDERLK]

Perhaps reading this will help the undecided.
http://www.nstmop.psu.edu/tasksheets/4.12 Tractor Stability.pdf

Seen this before and tho there is some good info there is also some wrong and some quasi wrong by virtue of being simplistic. For instance Fig 4.12.I and its explanation are wrong. There is no downward pull.

In the example of side stability the diagram does not take into account the front pivot that results in there being no front contribution to tip resistance until reaching the stops. At that late point extra front width gives a better second chance that may be able to stop the tip. It will be proportionally slight and the added width will be a drawback in virtually all normal usage.
larry

 

[texasjohn]

Best discussion of stability I've seen...excellent.

What I'm doing is using a dirt buggy, maybe called a dirt plane, draw bar attached to enlarge a dirt tank. You lower a ground engaging blade, pull forward filling a 3 cubic yard bucket as full as possible, then lift the blade turning the device into a trailer. I am getting between two and 2.5 CU of dirt on average per pull. I lose traction and have to feather the blade up and down during the pull to maintain forward motion and force dirt into the bucket. Then drive to dump location and dump the dirt and return to dig site. Along the way, to and from, there is uneven ground and slopes to navigate...not extreme and I always do it slowly to keep centrifugal force under control.

The paper makes it obvious why a sharp turn makes tractor more tippy....takes a wide front end and moves it more toward the tricycle type front end...narrows the COG stability base line. Further, in my case, in order to get maximum traction from front drive, when I'm pulling straight forward, I'm carrying a load of dirt in the FEL all the time. This does improve traction significantly, at a penalty of moving COG forward, closer to the edge of the COG stability base line.

Being safety aware, that's why I am interested in widening the front stance.

Kuboman, I'm interested in your comment re exponential stresses. Do you have an additional explanation about this? I understand the arc described by the front wheels during a turn. Seems to me that the stresses are as follows..

Rotational from the 4 wd...pulling forward... seems to me that this stress is the same regardless of tire positioning or turn radius.
Rim is bolted tightly to the axle so torque stresses are applied at the same point, reversed or not.

I'm just having a hard time understanding where the exponential stresses are coming from. For purposes of discussion, assuming a 1 foot wide tire encounters a 1 lb stress on its outer edge, then this is a 1 ft/lb stress seen at bearings. Repositioning that same tire such that it is now 2 inches further out from the perceived stress point this turns into a 1.2 foot/lb stress as seen by the bearings, seals, etc...I must be missing something, this seems linear to me.

Note, I'm not hardnosed about this...just wanting to get the most from my tractor under maximum safety conditions...can easily stay with old way...it's just that I've seen numerous discussions where people turned their front tires and this is the first time I've seen serious negatives expressed in 7 years of watching TBN.

Perhaps reading this will help the undecided.
http://www.nstmop.psu.edu/tasksheets/4.12 Tractor Stability.pdf

 

[vtsnowedin]

What I'm doing is using a dirt buggy, maybe called a dirt plane, draw bar attached to enlarge a dirt tank. You lower a ground engaging blade, pull forward filling a 3 cubic yard bucket as full as possible, then lift the blade turning the device into a trailer. I am getting between two and 2.5 CU of dirt on average per pull. .

Here they are called pan scraper or belly scraper or just scraper and are usually much larger then your unit. They have push and pull hook ups so a team of them can help each other load or they can be pushed by a dozer while loading and the dozer rips and softens things up while waiting for the scrapers to deliver their load. Great for large volumes of fine soil to be transported short distances.
You should use some loads to shape up the haul road as a better road will be safer and reduce your cycle time and hence your final cost. Experienced construction companies keep their haul roads graded to highway standards for the fuel and time they are saving is their own.

 

[texasjohn]

Yep, that's it...rented from Soil conservation district...$50 a day...less than the cost of diesel...I go thru 10 to 15 gallons daily when I can put in six plus hours.
Wish I had two tractors and two drivers...one to rip up ground, other to drive scraper...there's just me, so scraper has to do all the work. Too arduous to swap between scraper and ripper multiple times a day.

 

[kuboman]

Best discussion of stability I've seen...excellent.

What I'm doing is using a dirt buggy, maybe called a dirt plane, draw bar attached to enlarge a dirt tank. You lower a ground engaging blade, pull forward filling a 3 cubic yard bucket as full as possible, then lift the blade turning the device into a trailer. I am getting between two and 2.5 CU of dirt on average per pull. I lose traction and have to feather the blade up and down during the pull to maintain forward motion and force dirt into the bucket. Then drive to dump location and dump the dirt and return to dig site. Along the way, to and from, there is uneven ground and slopes to navigate...not extreme and I always do it slowly to keep centrifugal force under control.

The paper makes it obvious why a sharp turn makes tractor more tippy....takes a wide front end and moves it more toward the tricycle type front end...narrows the COG stability base line. Further, in my case, in order to get maximum traction from front drive, when I'm pulling straight forward, I'm carrying a load of dirt in the FEL all the time. This does improve traction significantly, at a penalty of moving COG forward, closer to the edge of the COG stability base line.

Being safety aware, that's why I am interested in widening the front stance.

Kuboman, I'm interested in your comment re exponential stresses. Do you have an additional explanation about this? I understand the arc described by the front wheels during a turn. Seems to me that the stresses are as follows..

Rotational from the 4 wd...pulling forward... seems to me that this stress is the same regardless of tire positioning or turn radius.
Rim is bolted tightly to the axle so torque stresses are applied at the same point, reversed or not.

I'm just having a hard time understanding where the exponential stresses are coming from. For purposes of discussion, assuming a 1 foot wide tire encounters a 1 lb stress on its outer edge, then this is a 1 ft/lb stress seen at bearings. Repositioning that same tire such that it is now 2 inches further out from the perceived stress point this turns into a 1.2 foot/lb stress as seen by the bearings, seals, etc...I must be missing something, this seems linear to me.

Note, I'm not hardnosed about this...just wanting to get the most from my tractor under maximum safety conditions...can easily stay with old way...it's just that I've seen numerous discussions where people turned their front tires and this is the first time I've seen serious negatives expressed in 7 years of watching TBN.

The farther you move the tire from the center of rotation (the king pin) the higher the forces are on the axle components. The ideal location is to have the king pin in the center of the tire. Kubota tries to accomplish this as best they can by rim offset. Just imagine if you moved the tire out several feet, an exaggeration I know but the extra forces on the axle would surely cause a failure in no time. Also there is extra force applied to the steering mechanism. IE, ties rods, steering gears etc.

 

[vtsnowedin]

The farther you move the tire from the center of rotation (the king pin) the higher the forces are on the axle components. The ideal location is to have the king pin in the center of the tire. Kubota tries to accomplish this as best they can by rim offset. Just imagine if you moved the tire out several feet, an exaggeration I know but the extra forces on the axle would surely cause a failure in no time. Also there is extra force applied to the steering mechanism. IE, ties rods, steering gears etc.

Words like surely are easy to say but I prefer to do the math. Lets look at a static diagram of a tractor front end with the tire set six feet wide . Lets set the load of the front of the tractor on the king pin at 3000 lbs including the weight of the axle and what share comes to the front axle from the load in the bucket. Then add in 300 lbs for each tire and rim centered three feet from the king pin. Now consider if we hold the right tire ridgely and remove the support from under the left tire what are the rotational forces placed on the flange of the right tire. I get 3000 *3 ft plus 300*6 feet for a total of 10,800 ft lbs of torque. Now set out the tires to a full eight feet. I get 3000 *3 feet (the flange to king pin distance didn't change) plus 300* 7 feet ( rt. flange to center left tire load) for a total of 11,100 ft lbs or a 3% increase.
I see nothing surly about a 3% increase causing a failure. Do you?

 

[RaydaKub]

There is going to be more wear on the front axle components as most of the guys have stated.
But there is no way this is going to provide more stability, especially if you add dirt in the bucket. Here's why.

http://www.tractorbynet.com/forums/...6-does-weight-fel-give-you-5.html#post3007695

Up to the point the tractor has tipped enough to hit the limit of the rocking on the axle, it provides no stability whatsoever.

 

[kuboman]

Hey man do what you will, just hope when you have a failure you lets all us skeptics know.:thumbsup:

 

[Chilly807]

Usually the owner's manual says whether or not you can safely do this. Here's the page from mine, for an L3400.. you'll also see that they make a reference to tapered or non-tapered holes in the rim. Mine are not tapered, and have washers under the flat side of the nut against the rim.



Sean

 

[KennyV]

There will always be someone willing to take a chance that the original equipment has an engineering safety allowance that will let them do something contrary to the owners manual...
Do as you will, but any additional loading on parts, with no gain, makes no sense to me.... and I have done many things that have exceeded recommended limits... I just don't do it when there is no real gain. and I know that just because I have not experienced a failure while doing it, I should not be surprised by shortened life of stressed parts...
If replacing parts is not a problem then it should be of no concern ...

With a wider stance on the front it will Always have additional forces on all front end components... Not just when you are operating at load limits... Things will always wear out... some times faster than other times.... and sometimes you can control just how quickly you are racing toward that failure.

 

[Bluegill2]

My manual says not to. My dealer says not to.

Like said, tractor pivots at the center of front axle, so it wont help any way...