Iseki tu1600 4wd out after loud bang

[Wetmatch]

Using my tractor the other day to move some dirt when I heard a loud bang noise, and my 4 ws does not work anymore. 2nd is fine, no noises when I drive or use any hydraulics. Where do I start? Driveline? Transfer case? Transmission?? Any help to point me in right direction would be awesome. I'm hoping it's something simple as a u joint on driveline broke. Anybody else have this problem??

 

[ruffdog]

Get the front wheels off the ground and rotate them. Does the front drive shaft turn when you do that?

 

[ericm979]

With the front end off the ground and not in 4wd, one wheel should turn backwards when you turn the other front wheel. If you turn a wheel while the other side is held in place the driveshaft should turn. The shaft may be inside a cover and not visible.

Sometimes there's a mechanical "fuse" in the drivetrain to the front axle, that is designed to fail first and not catastrophically when there's too much torque through the front axle. It should be in the shop manual, or a dealer should know about it if it exists.

 

[ptsg]

That tractor is similar to a Kubota B7000 I had. The overall construction is very identical, so I say it stripped the splines on the U joint for the front axle.

 

[Wetmatch]

Get the front wheels off the ground and rotate them. Does the front drive shaft turn when you do that?

Nope. Front drive shaft does NOT turn. And yes, it's in 2wd. Neither tire rotates while turning the other either. So, I assume the driveline joint is broken? There is a cover over it, but I can see whether it's turning or not, but not enough exposed to see the u- joint on front end of front shaft.

 

[Wetmatch]

With the front end off the ground and not in 4wd, one wheel should turn backwards when you turn the other front wheel. If you turn a wheel while the other side is held in place the driveshaft should turn. The shaft may be inside a cover and not visible.

Sometimes there's a mechanical "fuse" in the drivetrain to the front axle, that is designed to fail first and not catastrophically when there's too much torque through the front axle. It should be in the shop manual, or a dealer should know about it if it exists.

Nope, no turning of driveshaft when lifted off ground. And no turning of either tire while turning the other either?? unjoint ???

 

[Wetmatch]

Nope, no turning of driveshaft when lifted off ground. And no turning of either tire while turning the other either?? unjoint ???

 

[Wetmatch]

That tractor is similar to a Kubota B7000 I had. The overall construction is very identical, so I say it stripped the splines on the U joint for the front axle.

View attachment 859903

But wouldn't it make a bit of noise before going out completely if it were the spline ? Cause it ran perfect now for so long, and to just have a loud bang (like a u-joint breaking) all of a sudden just doesn't sound like a spline (to me anyway.) but what do I know . I appreciate any guidance I can get to fix it. I love my tractor, can't get along without it. Any ??

 

[Harry in Ky]

No matter what happens with the drive shaft, when one tire turns the other should turn in the opposite direction. Since that's not happening the driveshaft is not part of the problem. You need to dig deeper.

 

[Wetmatch]

With the front end off the ground and not in 4wd, one wheel should turn backwards when you turn the other front wheel. If you turn a wheel while the other side is held in place the driveshaft should turn. The shaft may be inside a cover and not visible.

Sometimes there's a mechanical "fuse" in the drivetrain to the front axle, that is designed to fail first and not catastrophically when there's too much torque through the front axle. It should be in the shop manual, or a dealer should know about it if it exists.

I'll check out what you said about mechanical fuse obit. I hope it's that easy . Thanks