Breaking front driving shaft on Jimna 284

[Brad_Blazer]

Originally Posted by Turbo

This why there is a differential to account for the two different wheel speeds in a turn one will lag behind while the other speed up. There is only one wheel driving at a time. They call it a four wheel drive , but in reality it's a two wheel drive one in the back pushing and one in the front pulling or a three wheel drive if you use the differential lock in the rear.
I know that you guy's know this. I put it here for those who do not understand it.

the fronts fail is because your asking one wheel to take on the weight of the tractor and load that has more torque than the part can take from the stress.

Each axle has a free differential (non-limited slip) meaning both wheels are supplied with the same torque as the least tractive wheel (significantly better than true 1WD in most situations)

There is no differential between the front and rear axles with fwd engaged. In a turn, the front axle (the path of the center of the axle or the average of the 2 front wheels) travels at a greater radius than the rear axle which means either the wheels slip or something breaks. "All wheel drive" vehicles do have a center (3rd) differential to allow operation on pavement.

[Iron Horse]

That is correct .

There is also the fuzzy grey area of the universals speeding up and slowing down twice every revolution that can't be compensated for . The universal on the outer wheel does this at a different rate than the one at the wheel on the inside of the turn because of the varying amounts of steering lock between the outside and inside wheel . That is why Constant Velocity joints are used on front wheel drive vehicles because as they are named , they are of constant velocity when at an angle , unlike a universal joint which is a NON constant velocity joint at an angle .

[63spyder]

on a four wheel drive tractor with a load /lots of traction, enough to break axles all four wheels are pulling not two or three.the diff helps compensate for the diffirent rates of travel the wheels are taking due to turning

[Aggieville]

Originally Posted by Iron Horse

That is correct .

There is also the fuzzy grey area of the universals speeding up and slowing down twice every revolution that can't be compensated for . The universal on the outer wheel does this at a different rate than the one at the wheel on the inside of the turn because of the varying amounts of steering lock between the outside and inside wheel . That is why Constant Velocity joints are used on front wheel drive vehicles because as they are named , they are of constant velocity when at an angle , unlike a universal joint which is a NON constant velocity joint at an angle .

+1, agreed.