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

   #1  

texasjohn

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Oct 11, 2005
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Central Texas, Jarrell
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Kubota Grand L5030HSTC
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?
 
   #2  

KennyV

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Kansas, Butler county, Just east of DooDah
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Kubota L4200 GSTCA
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....
 
   #3  

kuboman

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Canada
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B3200, L5740,
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.
 
   #4  

vtsnowedin

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central Vermont
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John Deere 5045E
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:
 
  
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#5  
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texasjohn

texasjohn

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Central Texas, Jarrell
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Kubota Grand L5030HSTC
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...
 
   #6  

David_Kb7uns

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Willamette Valley Oregon
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Kubota X 4
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
 
   #7  

Sawdustsmb

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Greene, NY
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KennyV is correct - no additional stability - and you cut on your tractor for only 4 additional inches?!
 
   #9  

kuboman

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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

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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
 
 
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