Tires Kubota 2012 M7040 Mitas tires badly cracked/aged with 330 hrs. stored inside

[Dave M7040]

When I bought my new M7040 with cab and FEL in Oct of 2012, I wanted R4 or industrial tires to minimize damage on lawns etc. rather than the R1 radials on it at the dealer.

Dealer had to order tires and wheels from Kubota as the sizes and thus wheels were different than the R1 for some reason.
I saw R4's arrive from Kubota on pallets.
I never gave the brand of tire a thought believing Kubota would not be putting junk on their new machines.

First clue something was odd was the fact that the tire size was not listed in my owner's manual in the chart showing what pressures to use for the different sizes.
Next, there was no information on the tire about load capacity at max pressure of xx although the larger rear tires had a caution of do not inflate above xx to seat the beads.
Not dealer nor Kubota Canada seemed to know what pressure to use. In the first week of use one front tire came off the rim when I was turning at slow speed. Obviously not inflated enough!

The tractor is stored indoors, almost only used for snow blowing and after 4 years has 330 hrs. The orange paint looks new.

I was putting my tire chains on and to my horror noticed extensive cracking on the tread surface around the lugs.

I am kicking my *** for ever accepting these MITAS tires in the first place.

Mitas (Mitas | United States) is a Czech-based manufacturer of off-road tires (agricultural, industrial, motorcycle). The history of Mitas dates to the 1930s, when tire production started in Prague, the then capital of Czechoslovakia, and in the Moravian city of Zlin. Mitas currently operates three plants in the Czech Republic, one in Serbia and a new one in Charles City, Iowa

They built a tire plant in the USA in 2012 so mine had to come from Czech. to be on a 2012 tractor.

Sizes are 12.5 x 20 12 ply rating on front. 16.9 x 28 12 ply on rear.

Does anyone else have these on their tractors?

I will be writing to Kubota Canada but not expecting much after 4 years.

I will take some photos and post once the snowing is over.

Dave M7040

 

[oosik]

My owners manual - 2009 M6040 - does not list this size/ply rating either. It does list 16.9 x 28 6 ply for the rear @ 18 psi. Nothing for your size/ply rating for the front. It does list 9.5 x 20 6 ply for the front @ 29 psi. This inflation pressure chart supposedly covers tires for M5040, M6040 & M7040.

I'm surprised that MAX load rating is not molded into the sidewalls of the tires.

Anyhow - I would definitely say that a tractor thats been stored under cover for only four years and shows the situation you described has bum tires.

I'm only directly familiar with Titan, Firestone, Goodyear & Carlisle. My previous tractor had Goodyear on all four, was always stored under cover and showed no cracking anywhere after 27 years - when I traded it for my current Kubota M6040. I've always had R-1 tires. Current tractor has Titans up front and Firestone on the rear with no cracking after seven years.

My John Deere - G100 - lawn & garden tractor has R-4's and shows no cracking after 13 years. It has Carlisle tires.

 

[LD1]

Any pictures of the cracking?

 

[JWR]

Like LD1 I'd like to see pictures of what you describe. A few comments and datapoints: We replaced the AG tires on a Massey Harris which is garage-kept around 35 years ago. They do show some cracks around the lugs but it does not seem to matter. I also have a Kubota B2150 with turf tires that are the originals being around 33 years old. They show some cracks I call minor and the tires function fine. What is "badly cracked" is relative. It's always possible you have a really bad set of tires but I doubt there is much wrong with tires bought in 2012. Cracks are not necessarily cause for alarm.

 

[AStanton]

I'm wondering if foaming them could lengthen their life and the cracks would no longer be a factor.

 

[Farmer495]

Have a M7040SU with Cultor 420/85/28 (16.9-28) and Kleber 360/70/20 on front. No issues in the 2 years since the tractor was built, approx 280 hours on it. Sat outside on the lot for a year, then inside since it came here.

There was a local guy had something similar happen with his new Kubota, think it was a M7040 or slightly bigger. Don't recall what brand the tires were, but the tires all cracked to pieces. He apparently had to fight to get warranty to cover it. Heard this 2nd hand so not sure on all specifics.

Kubota Canada puts a really nice Metric radial R-1W package on the M series, that US sold Kubotas do not get, that's why the tires aren't in the operator's manual. Front tire size not listed my manual either, rear is, but my speed chart shows 16.9-30 as the size (same size sales literature states as standard)

I noticed all the new M7040SU and M7060 on the lots all have 420/85/30 (16.9-30) and 360/70/20 on front, various rear brands.

Only seen a handful in ads with the R4 tires like you have.

 

[Dave M7040]

Gentlemen

Finally a few pictures. Snowing and cloudy + chains and snow on tires limited what photos I could take.

These are pretty typical of the cracking on the rear tires. The fronts are perfect. Same TITAN brand but different size.

Dave M7040

 

[JWR]

Good for another 15 or 20 years. Somewhat kidding, but I would not worry about those tires at all. If still concerned, you might want to mark the places on the tires where these were taken and take a new set of pictures 6 mos. and then a year from now. If you use the same degree of "close-up" you will then be able to see if the cracks are growing significantly or not. I believe they are superficial.

I had Titan tires on a John Deere 4700 for 10 years (new in 2000). The tractor is still in the family and still running the original tires. I also run Titan tires on my Massey Ferguson 2660 which were new in 2011. You may know that Titan bought out the former Goodyear off-road tire manufacturing and distribution assets in the midwest around 5 years ago.

 

[Dave M7040]

JWR
Thank you for your thoughts.
If the tires came from a re-branded American Goodyear plant I would have some confidence. From Czech less so.

If the tires were on my 1960's Nuffield 465 and I watched them get to that state of visible cracking over decades, I would have a good sense of their reliability based upon my experience with them during that time.

I have some baggage re tires: In the 1970's I was employed by the Canadian Government as an automotive engineer and accident investigator. My job was to investigate the worst accidents across Canada looking for manufacturing defects. This was the era of Steel belted radial tires. I cannot tell you these many years later how many coroners' inquests I testified at where a tire had failed and a family wiped out.

I spent days and days in Goodyear's car and super large earth mower tire manufacturing plants trying to see which features or materials were causing the steel radials to fail so dramatically and early in their lives.

All this was many years ago and my knowledge is way out of date. In the back of my mind has the Czech made tire evolved to modern design and testing or are they still back in the 1960's.

When I could not find any inflation info for my size of tire in the operators manual I started bugging my dealer and then he started bugging Kubota Canada.


Here is the info provided: Inflate rears to 37.7 psi. At that they will have a load capacity of 7639.8 lbs Inflate front tires to 50.6 psi At that psi they will have load capacity of 4806.0 lbs

Considering I have two rear and two front tires my tractor can have a total gross weight of 19,224 lbs.

That is obviously stupid. The tractor would have wheels like Barney Flintstone.

I have chosen pressures reflective of the ones for closely sized tires.

Merry Christmas

Dave M7040

 

[JWR]

Wow Dave. I'm shocked that Kubota suggested those kind of tire pressures ! Way off. I would just go by the pressures printed on the side of the tires. For ballpark numbers from memory (which I have NOT looked up) the front tires should be around 26psi and the large rear tires should be around 18psi. That is what I run on my Massey Ferguson with 18.4 x 26 rear and 11.2x24 front tires. Those sizes are all in inches, not metric. Possibly the pressure numbers quoted were metric instead of psi ?? I am not familiar with the metric units for pressure. Yes, I agree that 50 psi and 37 psi are stupid. Just go by the numbers on the sides of the tires. Do those tires say they are Czech made ?

Headed for bed down here in the states. Merry Christmas to you too ! jwr