That dreaded "Pop" sound

[jinman]

I'm stating all this in thinking that all the 4WD CUT NH front axles are built in a similar manner. Posting any failed or weak link part will help everyone in the future...

I don't know anyone with statistical info except maybe NH, and they aren't releasing it. My guess is that groups of tractors have similar problems due to manufacturing runs of parts, but not all tractors of the same type are affected. That has been the case with previous problems. At least, I'm hoping that's the case. I've worked my TC45D very hard in 4WD, but normally I apply loads gently and progressively rather than using rough and abrupt operation. Still, while turning, I've hit holes, rocks, and uneven conditions I didn't notice and got a pretty good jolt.

What I'm afraid of is that during disassembly and inspection, I'd likely introduce more problems than I'd be preventing. Don't know for sure....

 

[housemasters]

Ok, here's what happened...the pinion gear shaft snapped in two just as I had thought.
Has this happened to anyone else?
Will be getting in touch with dealer to see if NH will cover this, because the pinion shaft should not be the weak link in the driveline. I would think they would have designed it to have the splines on the driveshaft couplers as the weak link?
Thoughts?

 

[sweep]

Getting back to driving on pavement while in 4wd. I drove my TC 45(manual shift not hydro D) to the dealer on a paved road and believe I left it in 4wd.
Total distance was about 3.5 miles each way.

My tractor now has 28 hours on it and works fine.

Did I cause any damage?

 

[mike69440]

When I had my TC-30 in the shop for some work the guy there cautioned me on using the loader in 4WD. He said the extra strain on the front end could break the gears. Sounds like what happened to you.

That does not sound right that a tractor is designed not to be used in 4WD with the loader pushing and lifting.

Although I avoid doing so where I can, in the work I do have knowingly put max. strain on the front axle of both my little B7200 Kubota & L39TLB lifting against the relief valve and spining both the front and rear tires on hard ground in 1st gear. Using the L39 as described there is so much load on the front axle the rear tires almost lift off the ground.

 

[dogbreath108]

Rick,
Just my 2 cents, but I don't believe there is a engineered weak link. The driveshaft coulper is a super tough piece, and I would think you would have a hard time poping it before something else went. If you lost something else in the differential you might have damaged a lot more items. Maybe you just had a slight imperfection on the shaft. Did it shear between the two bearing surfaces (the area that is slightly recessed about 3 inches back from the gear)? Also, were you in the lowest of low range when it happened?
Hope you have a repair manual if you are going to put it back together your self. There are I think three clearances you need to check and possibly redo with more or less shims. Good luck and let us know how you make out. By the way, I have heard of many ring gear bolts and bevel gears going on all makes of CUTs but never the shearing of the pinion shaft. Maybe you should get a prize...

Joe


Sweep, your probably fine.... If you had something very heavy in the loader that whole time it might be a different story.