Lead/lag ??? on Grand L series

RFB · Feb 7, 2006

"What do you...think?"

Quite frankly, not very surprised. While trying to understand this issue and communicating with a dealership and a tire shop, I have found a dearth of knowledge regarding this issue, as well as vacuity when it comes to the custom hydraulic modifications as accomplished by several on this site. (As an aside, Rick Wallace, a PA Kioti dealer I spoke with extensively when I was still considering tractor make and model, was exceptionally gracious, informative, cogent, and demonstrated consistent intellectual integrity.)

I live very rural, and dealer selection is very distant. Nonetheless, they are very "proud" of their products. Two dealers never returned phone calls to obtain initial sales information; another told me my choice "could not be done" (I wanted to order "no onions"), and another quoted me a price that was $10,000 more than listed MSRP, and with a straight face.

What I have found as a general rule, is that asking for anything outside of a very narrow selection is like going into a burger shop and ordering the standard, with no onions:

"What?, no onions?" Correct, no onions. A hush comes over the kitchen, heads come together in conference, "he wants no onions" is whispered among the workers, the counter attendant proclaims, "No onions...hmmm...well that is highly irregular"
while the manager comes forward to deal with this "self-appointed expert".

LRH · Feb 7, 2006

( Having read the above thread and being the owner of a new 3830 with r4's, I was concerned enough to call my dealer who then refered me to the Kubota rep in CA. The rep was forwarded a link to this thread along with links to the Tractorsmart calculation page. Bottom line is the rep was no help whatsoever and in fact somewhat curt in his response---
-(he said Kubota has done the engineering for correct lead and this tire setup is approved while any other setup( like the larger front tire suggested by ttown66) is not and would(presumably) affect the warranty of the tractor. He was not kind to "the self appointed experts on the forums". There was a thread a while back about the r4 fronts having a clearance issue with the front end loader on tight turns---I wonder if this could have led to the use of a smaller tire on the front? Since Kubota was so dismissive, I am wondering how to find out more about this. What do you other affected owners think?
K )
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Most likely just a talking head, prob had to put you on hold to find out what lead/lag was; and then give the standard answer. Math doesn't lie, but Kubota must think this is a small enough tire size difference to get most through the warranty period.

mojavedesert · Feb 7, 2006

A talking head is right. I asked if he disagreed with the formula on Tractorsmart and/or if Kubota used an alternative formula. His reply--"all I can tell you is the stock r4's for the 3830 are engineered and approved by kubota".
Has anyone on the forum with an L serires and the 753 loader run a larger front tire like the one ttown66 mentioned(Titan 12-16.5 #49E3J7) ? My only concern would be clearance with the loader arms on tight turns. I guess another option would be to swap out the r4's for the stock ag tires---I don't have the specs on these yet, but my impression from previoius posts is they would be in the acceptable range.
Can anyone else verify that the grand L mechanical gear ratio of 1.5640 is correct ?
K

CT_Tree_Guy · Feb 7, 2006

What do I think ... hmmm ....

I think I'm a little tired of people like that Kubota rep who would rather attack others than own up to the truth. We all make mistakes, but it's been my experience that their repercussions are compounded by lying about them. Witness Bill Clinton, Martha Stewart and Richard Nixon.

Lying about their seemingly obvious mistake on sizing R4's on some of their tractor models is bad enough, but to then attack those who have gone to the trouble of determining "the truth" as "self-appointed experts" ... what do I think about that? I think it makes me sick, that's what i think about that.

Here's part of a post I made in New wheels for L3130? :

 According to many, many sources I contacted or researched (Michelin, Titan, Pete's Tire Barn, online resources, anyone who seemed to know anything), ANY amount of lag is unacceptable. The stock R4's being sold with [some] Grand L's, at least at that time (April '04) had a lag ratio of more than 3%. It might seem like much, but evidently it is off-the-charts bad.

When I called this to Kubota's attention, they squirmed a bit, said they had meetings to go to, shuffled me around, and finally said something to the effect of "Yeah, well, sometimes some compromises have to be made due to procurement procedures and contractual obligations with suppliers, but if you boost the air pressure in the fronts, that might help somewhat by increasing their rolling circumference to bring the lag ratio to a less unacceptable level". Naturally, I passed on that advice. 

Give me a break Kubota. You make a great tractor, but we can all do without your apparent lies. If I'm wrong, I'll apologize. It would be nice if you could do the same. That's what I think.

John D.

ttowne66 · Feb 7, 2006

mojavedesert

Thanks for going the extra mile and contacting Kubota! For the Rep's informatin, I believe that no one is claming to be an expert here, we are simply trying to get answers. His answer should have been simple with no need to put put people down for trying to get information. The fact that he handles this situation by heading down the road he chose is curious, especially when he answers your question with the comment "all I can tell you is the stock r4's for the 3830 are engineered and approved by kubota" . Sounds like a stock "company policy B.S. answer" if I ever heard one. In my opinion, any answer not consisting of a mathematical calculation is highly suspect. If you can still get in touch with him, I would be interested in finding out exactly how theis rep calculates lead for these tractors.

Tom

slowzuki · Feb 7, 2006

I'll claim to be an expert lol, maybe not but I'm a mechanical engineer and given the numbers kubota would be in the wrong but they are obviously acceptably in the wrong since the tractors are holding up even when driven on pavement in 4wd.

And yes, Glenn had big front tires on his l3430 with a 723 loader and yes their were physical mods made to get them to fit.

mojavedesert · Feb 7, 2006

ttowne66
Well..... I did ask for an alternate formula and got the "kubota has engineered and approved ,blah, blah, blah" response.
It is interesting that the Titan website recommends an 8.25" wide rim for the 10-16.5 tire, but kubota mounts this tire on a 9.75" wide rim---it seems like this would just compound the problem. BTW, where can reference to the kubota gear ratio be found----anyone?
K

CT_Tree_Guy · Feb 7, 2006

Mojave, I think the ratio you're looking for is 1.5460. By the way, it doesn't look as if anyone's welcomed you to TBN, so ...
Hey, welcome to TBN!

I thought that was a heck of a first post by the way. Very interesting, hard-hitting investigative reporting - I think "60 Minutes" will be calling you any day now. /forums/images/graemlins/smile.gif

That is still bugging me, that somehow none of our opinions or observations matter, or are valid. I often hear posters say things like "hey, you can't believe any of the stuff that's said here, it's all just opinions, it's just hearsay, etc., etc., etc......"

To which I sometimes say ... "then what are you doing here?" ... "why did you just quote something you just read here?" ... or, "why then should I believe what you say?". The answer to those arbitrary questions seems obvious ... to me, it's because there is an incredible wealth of truth and knowledge to be found here. And as for why that is sometimes not more readily acknowledged; for any particular person, group or organization - the "truth" might be either friend or foe.

As for me, I've always loved the truth, as best it can be dispassionately determined; and I sure hope I always do.

mojavedesert · Feb 7, 2006

CT--Thanks for the welcome. I've been "mining" the site for info since I started shopping for a tractor. Some knowledgeable and generous peaple here! I just wish I had found the tire info before I ordered the r4s. The kubota rep attitude is very aggravating but at least I have a decent dealer who is easy to work with--perhaps I can work an exchange for the ag tire setup. If anyone out there has tried the 12-16.5 r4 on the front, please post the result---clearance, handling ,etc.
K