Hello all,
I have a UK model year 1999 L4200 MFWD tractor.
The turf tyres it came on are worn low on the rear and nearly new on the front, cheapskates!
The tractor also came with a set of Ag wheels and tyres that have lots of tread, these however are not the kubota OEM size for the L4200, but rather the L3200!
So this left me in a dilemma to try and work out what I should do.
Having read the recommendation that MFWD should have front wheels which rotate slightly faster than the rears ( 3-7% kubota).
This lead me to doing the calculations for 3 seats of wheels
The fitted Turf tyres
Front: tyre size 29 x 12-00-15 Rolling Circumference index- 2172mm
Rear: tyre sze 475/65D20 Rolling Circumference index 3236mm
The formula
((Front Rolling circumference index/ Rear rolling circumference) x final drive ratio)x100 = lag/lead percentage - Understanding the result- answer is less than 100 front tyres lag, answer is greater than 100 , front tyres lead.
I took the gear ratio from a forum post, as 1.57
Now the turf tyre result is 105.3%, so an ideal lead of 5% on the front tyres. Great at least I know its been driven on decent ratios
For the Ag tyres supplied when I bought the tractor (marked as from an l3200)
Front: tyre size 8-16 Rolling circumference index - 2342mm
Rear: tyre size 11.2-24 RCI - 3314mm
Working through the calculation I get 110.9%, this is a front lead of nearly 11%.
Okay, now to check the Factory OEM service book tyre sizes -
Front: tyre size 8.3-16 RCI 2342mm
Rear : tyre size 14.9-24 RCI 3837mm
Result = 95%
Now this is a lag where the front wheel spins slower than the rear!
My question is can I safely use the ag tyres with an 11% lead, using the mfwd( which is stuck engaged)?
I have a UK model year 1999 L4200 MFWD tractor.
The turf tyres it came on are worn low on the rear and nearly new on the front, cheapskates!
The tractor also came with a set of Ag wheels and tyres that have lots of tread, these however are not the kubota OEM size for the L4200, but rather the L3200!
So this left me in a dilemma to try and work out what I should do.
Having read the recommendation that MFWD should have front wheels which rotate slightly faster than the rears ( 3-7% kubota).
This lead me to doing the calculations for 3 seats of wheels
The fitted Turf tyres
Front: tyre size 29 x 12-00-15 Rolling Circumference index- 2172mm
Rear: tyre sze 475/65D20 Rolling Circumference index 3236mm
The formula
((Front Rolling circumference index/ Rear rolling circumference) x final drive ratio)x100 = lag/lead percentage - Understanding the result- answer is less than 100 front tyres lag, answer is greater than 100 , front tyres lead.
I took the gear ratio from a forum post, as 1.57
Now the turf tyre result is 105.3%, so an ideal lead of 5% on the front tyres. Great at least I know its been driven on decent ratios
For the Ag tyres supplied when I bought the tractor (marked as from an l3200)
Front: tyre size 8-16 Rolling circumference index - 2342mm
Rear: tyre size 11.2-24 RCI - 3314mm
Working through the calculation I get 110.9%, this is a front lead of nearly 11%.
Okay, now to check the Factory OEM service book tyre sizes -
Front: tyre size 8.3-16 RCI 2342mm
Rear : tyre size 14.9-24 RCI 3837mm
Result = 95%
Now this is a lag where the front wheel spins slower than the rear!
My question is can I safely use the ag tyres with an 11% lead, using the mfwd( which is stuck engaged)?