JONNY BOYYYE
New member
- Joined
- Dec 28, 2023
- Messages
- 22
- Tractor
- KUBOTA 4330
PROBABLY WILL RUIN THE TRANSFER CASE BUT CHECK WITH A DEALER TO BE SURE..THAT INFORMATION IS FREE..
Taller tire replacement
- Thread starter Randy Helms
- Start date
ernieatv
Member
Lol, ask your kids or neighbors or friends to help you, you must have one out of three that could help you. Tires have to be the same size on both sides either front or rear
Paul McILwain
New member
- Joined
- Sep 26, 2022
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- 19
- Tractor
- LS 5030C/MF220-4/ Satoh S650
Not sure why tires marked the same size would have different dimensions. Just changed a tire yesterday, I am 82
I have been an ag mechanic for a long time. I want to give you some more information about tire sizes and differentials and 4 wheel drive tractors.
First, the tire and wheel sizes on a 4 wheel drive tractor are picked by the manufacturer to be compatible, ie., one driveshaft revolution moves over the same amount of ground on the front and rear axles. (actually front tires might cover 1 to 2% more to help turning) This is done by tire and wheel size selection and front and rear end pinion gear ratio selection. If you change tire sizes, and a 3 to 4 inch diameter change on rear tires(which are big) is a very big difference in ground covered, you will make a big change in the distance covered by the front and rear wheels and that will put a lot of pressure on all the driveline components. The problem will be worst when you drive on pavement, but even on soft ground, the tires on one axle will always be turning faster than the other. The damages in order of severity will be: excess tire wear, drive shaft damage and u joint damage, excess wear to ring and pinion gears in front and rear axles, and most expensive, damage to internal transmission components which will require splitting the tractor to access the transmission gears supplying power to the driveshafts and possibly the transmission gears themselves. You really don't want to risk this.
A quick way to tell if there is pressure on driveline components is to engage 4 wheel drive, move 100 feet, and see if you can disengage 4 wd easily. If it is hard to move the lever, or there is a pop when you disengage 4 wd, there is pressure on the driveline and you need to be sure the tire and wheel sizes are compatible. The best solution is to make sure the tire diameters are exactly the same as the OEM tire and wheel set. (All wheel drive cars, which always drive all 4 wheels on pavement, use a special differential to split the drive to front and rear driveshafts and allow them to turn at different speeds for a short time. Even with the differential, car manufacturers caution that all 4 tires must be the same brand and have the same amount of wear to prevent damage to the transmission. Replacing just two tires will cause damage to the transmission.)
A differential is put into the front and rear axle to allow the right and left wheels on each axle to turn at different speeds for a short time while going over uneven ground or around a corner. Two different sets of spider gears on shafts to do that. The spider gears and shafts are not built and lubricated to run for long periods of time, so running two different tire sizes on the same axle will turn the spider gears into metal powder quickly. Tire sizes on the same axle must be the same to avoid damage.
There is no differential between the front and rear driveshafts on a 4 wd tractor so any speed difference between front and rear driveshafts will cause almost instant damage unless the tires can slip on a soft muddy surface to relieve the pressure.
If you want to change the tire sizes on your tractor, best to check with tire manufacturers and your tractor manufacturer to make sure that the sizes will work together, otherwise damage can happen before you even notice a problem.
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First, the tire and wheel sizes on a 4 wheel drive tractor are picked by the manufacturer to be compatible, ie., one driveshaft revolution moves over the same amount of ground on the front and rear axles. (actually front tires might cover 1 to 2% more to help turning) This is done by tire and wheel size selection and front and rear end pinion gear ratio selection. If you change tire sizes, and a 3 to 4 inch diameter change on rear tires(which are big) is a very big difference in ground covered, you will make a big change in the distance covered by the front and rear wheels and that will put a lot of pressure on all the driveline components. The problem will be worst when you drive on pavement, but even on soft ground, the tires on one axle will always be turning faster than the other. The damages in order of severity will be: excess tire wear, drive shaft damage and u joint damage, excess wear to ring and pinion gears in front and rear axles, and most expensive, damage to internal transmission components which will require splitting the tractor to access the transmission gears supplying power to the driveshafts and possibly the transmission gears themselves. You really don't want to risk this.
A quick way to tell if there is pressure on driveline components is to engage 4 wheel drive, move 100 feet, and see if you can disengage 4 wd easily. If it is hard to move the lever, or there is a pop when you disengage 4 wd, there is pressure on the driveline and you need to be sure the tire and wheel sizes are compatible. The best solution is to make sure the tire diameters are exactly the same as the OEM tire and wheel set. (All wheel drive cars, which always drive all 4 wheels on pavement, use a special differential to split the drive to front and rear driveshafts and allow them to turn at different speeds for a short time. Even with the differential, car manufacturers caution that all 4 tires must be the same brand and have the same amount of wear to prevent damage to the transmission. Replacing just two tires will cause damage to the transmission.)
A differential is put into the front and rear axle to allow the right and left wheels on each axle to turn at different speeds for a short time while going over uneven ground or around a corner. Two different sets of spider gears on shafts to do that. The spider gears and shafts are not built and lubricated to run for long periods of time, so running two different tire sizes on the same axle will turn the spider gears into metal powder quickly. Tire sizes on the same axle must be the same to avoid damage.
There is no differential between the front and rear driveshafts on a 4 wd tractor so any speed difference between front and rear driveshafts will cause almost instant damage unless the tires can slip on a soft muddy surface to relieve the pressure.
If you want to change the tire sizes on your tractor, best to check with tire manufacturers and your tractor manufacturer to make sure that the sizes will work together, otherwise damage can happen before you even notice a problem.
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Last edited:
Jaygyver
Member
Feeling the OP's pain there.
Are you looking by eye balling the two sitting next to each other? One mounted and the other bare? They will look different.
Check the manufacturers original radius size and then compare it to the one your looking at, just to be on the safe side. Unless your original tires are pretty worn then the new one should shorten and widen out once mounted.
My journey into buying tires:
600 x 12 is NOT the same size as 6.00 x 12..... 6.00 is 3 +-inches taller than the 600. For my 4x4 that was a no go.
A few years back my JD-770 front R1 tires were getting pretty bare when it dawned on me I maybe should get new ones. Firestone discontinued my size. Asked my JD dealer what would be the replacement size, his answer was "don't know ask Firestone". So your supplier discontinues them and corporate doesn't know a compatible size?
Spent many months finding replacements. I first had to find out what the factory radius size was on the original tires then look for a similar tire from different manufacturers. I just went by the radius listed in the spec sheets for the tire size i needed from the manufacturers.
My issue was the difference from front to back axles and yours is on the same axle but as been mentioned it may still effect the drive train.
Are you looking by eye balling the two sitting next to each other? One mounted and the other bare? They will look different.
Check the manufacturers original radius size and then compare it to the one your looking at, just to be on the safe side. Unless your original tires are pretty worn then the new one should shorten and widen out once mounted.
My journey into buying tires:
600 x 12 is NOT the same size as 6.00 x 12..... 6.00 is 3 +-inches taller than the 600. For my 4x4 that was a no go.
A few years back my JD-770 front R1 tires were getting pretty bare when it dawned on me I maybe should get new ones. Firestone discontinued my size. Asked my JD dealer what would be the replacement size, his answer was "don't know ask Firestone". So your supplier discontinues them and corporate doesn't know a compatible size?
Spent many months finding replacements. I first had to find out what the factory radius size was on the original tires then look for a similar tire from different manufacturers. I just went by the radius listed in the spec sheets for the tire size i needed from the manufacturers.
My issue was the difference from front to back axles and yours is on the same axle but as been mentioned it may still effect the drive train.
toomanymachines
Member
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- Jan 9, 2014
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- 36
- Location
- manitoba
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- pasquali holder new holland challenger komatsu john deere kubota allis and international
I would return the tire and get something like a goodyear duratorque. it will be closer in size, and better quality. Carlisle is bottom of the barrel. also putting two carlisles will put more stress on the ratio of the front tires to the back tires on a front wheel assist.
xtxpete
Bronze Member
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- Mar 18, 2019
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- Ontario
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- McCormick XTX 165, Case IH Cx 90, 445 skidsteer, Cub Cadet UTV, Farmall M
Maybe the OP has changed his mismatched tires by now....but depending on how much use the tractor gets and how long his tires last, I would suggest adjusting air pressure in the old tire upwards a few psi and setting the new taller tire at the pressure where the distance from the ground to the center of axle is equal on both wheels, then they will roll "together"
rScotty
Super Member
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- Apr 21, 2001
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- 8,258
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- Rural mountains - Colorado
- Tractor
- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
Not just the same on both sides, but if the tractor is going to be used in 4wd, the ratio between the front and rear tires has to be the same as what it came with from the factory.
That is because tractors don't have a middle differential like an AWD car does.
The gear ratio between the fronts and rears is set by the size of the internal gearing that it came with when new - gearing which is selected by the manufaturer to match the original front and rear tires.
rScotty
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