# Now I know what that Bang I was getting was...



## RuttedField (Apr 24, 2016)

It was the spider gears in my front, left axle. (About a $1000 fix).

For the last several months, whenever my little Kubota Tractor was in four wheel drive and I backed up, it would make a loud "bang" sound. Since it was in 4X4 and always in reverse, it did not happen that often. Today though as I tried to load some gravel into my dump wagon, you could hear the gears in the hub stripping as I spun. DRAT!

The thing is, it really was not my fault. My old front tires got kind of bald so my father had the local garage throw regular light truck tires on it. I told him not to, but he did anyway and right after that we started hearing the bang; I am assuming from mismatched ratio's on a 4X4 tractor.

I got about four broken machines awaiting to be fixed right now, so I guess it is good I pumped out 34 cord last week, but it looks like all my wood this week will be coming out by bulldozer. These sized tractors work well in the woods, but they need four wheel drive to do it.


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## slowzuki (Mar 8, 2011)

Yup, wrong tire sizes on hard surfaces or heavily loaded will take out front axle parts or driveshaft parts in a hurry.


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## mlappin (Jun 25, 2009)

Yep, same goes for articulated tractors, if your gonna put new rubber on the front then you need new rubber on the back as their is no differential between the front and rear, if it spent its whole life in the dirt you might get away with it, have mismatched rubber on the front and back and road it much then it can get ugly fast.


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## SCtrailrider (May 1, 2016)

It doesn't take much with the wrong height tires, the same as for a truck & 4x4, they need the right size tires or breakage will happen...


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## Coondle (Aug 28, 2013)

slowzuki said:


> Yup, wrong tire sizes on hard surfaces or heavily loaded will take out front axle parts or driveshaft parts in a hurry.


Need to be careful if changing/renewing tyres on 4wd /FWA tractors because few have a power divider between the two differentials like tandem drive trucks do.

Last year I needed to change the profile of the front tyres on my Foton fwa tractor because the OEM tyres were low profile (8.3.24). The low profile and poor load carrying capacity gave me much grief with the front end loader. Though only a 60 hp tractor it can lift 1000KG (2200lbs), with water ballast in the rear tyres. The low profile 8.3's would puncture when a rock or other object pinched the tube with the loader in use.

My solution was to fit 8.25.20 truck tyres. Load carrying of these truck tyres is far superior to the tractor tyres which are made for pulling not carrying. To achieve this I acquired 2 truck split rims (i.e. rims of a spider style hub) and had a wheel-centre manufacturer make up the centres and weld them into the rims. I gave the centre diameter which is critical as the rim centre carry the weight on the hub not on the wheel nuts and studs. In also provided the PCD (pitch circle diameter) i.e. the diameter the wheel studs are at and the number of studs. AS there were 6 studs the distance between the studs is exactly the same as the diameter the studs are at. Neat geometry  .

In selecting the tyre of choice I hunted through the internet trawling a range of tyre sizes to match the rolling diameter of the OEM 8.3.24 tyres. It turned out that the 8.25.20 truck tyres were within 5 millimetres of the OEM and using well-used truck tyres, after all I did not want to overcapitalise the end result is even closer.

The downside is if I have heavy draught work to do I have to revert to the OEM tractor tread tyres to get the grip needed. But using the fel bucket to jack up the front and an air rattle-gun the changeover is relatively quick and painless.


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## somedevildawg (Jun 20, 2011)

No need to over capitalize Kevin......


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