Broken Tie Rod on my 4500

[MMH]

I broke my tie rod on my 4500 today. Bent it like a pretzel. I've been running the tractor pretty hard lately, but nonetheless, was surprised at this. I have been moving tons (as in several hundred ) of gravel not to mention the earth moving (heavy clay & shale). The front tires cut their own tracks and the steering has to work pretty hard to break out of the ruts. Iwould have thought that the power steering would have a limiting valve that would open up before parts would break, but I guess not.

Anyway, I guess that I will have to remove the power steering cylinder & get it rebuilt at JD. I imagine that the hardest part will be breaking the ball joints loose at the spindles. Will this be as simple as driving a pickle fork to separate the tie rod from spindle? I don't want to tear up the rubber boot on the ball joint. If the tractor wasn't in such a bad place I would put the whole thing on a trailer, but, at this point, I'm not sure that's an option.

 

[dfkrug]

Does your tractor use a 2-ended cylinder, or a one-ended cyl with
tierod? If you have to remove the tierod ends, the best way is to
hit the side of the casting, after removing the nut, or use a sledge
hammer on the stud, after loosening, but not removing the nut. I
protect the stud with a big chunk of aluminum.

Those are big tierod ends, so a big picklefork is needed if you try it
that way. Mine was not big enough, and I did not want to tear up the
rubber boot.

 

[MMH]

It's worse than I thought. The rod that the threaded part of the tie rod connects to (the part that exits the cylinder, about 1.1" dia and looks like a hard-coated nitrided surface) is broke. Looks like it's time to get the cylinder rebuilt.

The rod broke half way in the cylinder. A clean break pretty much perpendicular to it's axis. I'm even more surprised that this part broke.

 

[dfkrug]

Yeah, that's surprising. And your cylinder does not have a removable
gland, correct? So, it has to be cut open to fix it. I suggest that you
buy a cyl from SurplusCenter and weld on new ends. Or have it done.
You will not like want JD wants for a new cyl....

 

[MMH]

Cannot find the part used. Dealer cannot rebuild, part is only sold as an assembly. $951 for just the part. Anyone know of a used JD parts salvage yard? I called up all the ones I could find on the web!

 

[dfkrug]

The least expensive solution will be to customize a generic cylinder. Here is a
photo of one made up for a JD955. The cyl is from SurpCntr, and the welded-on
ends were from an auto parts store.

On my first 4300, I was able to save the cyl, but I subbed a large truck tie rod end
and welded it on.

Even if you buy the parts and take it to a shop, you should be out less than $350.

 

[zzvyb6]

It's worse than I thought. The rod that the threaded part of the tie rod connects to (the part that exits the cylinder, about 1.1" dia and looks like a hard-coated nitrided surface) is broke. Looks like it's time to get the cylinder rebuilt.

The rod broke half way in the cylinder. A clean break pretty much perpendicular to it's axis. I'm even more surprised that this part broke.

Probably broke in tension: Hydraulic power + you reefing on it was more force than it was designed for.

Machines need respect, too.

 

[MMH]

Probably broke in tension: Hydraulic power + you reefing on it was more force than it was designed for.

Machines need respect, too.

Not that it matters, but doubt that it broke in tension. The rod is 1.1" in dia, and probably from a high strength steel (e.g. 4140, don't know for a fact, just an example). It would probably take 75,000 to break it in tension. My guess (and this is just a guess) is that it broke from buckling/bending. The only thing that I don't understand is that it broke iNSIDE the cylinder and teh buckling/bending would be limited by the brass bushings.

As far as me reefing on it, don't know. It is a steering cylinder. I'm moving alot of gravel now & in general doing alot of earthmoving. I am working in heavy clay, and the wheels frequently rut. Eventually they hit firmer clay and it has to be like an impact load to the front wheel. I try to be careful and not fly thru stuff at speed, but short of moving very, very slowly, the wheel will hit firmer stuff & get some 'kickback' - it's going to happen. One way for it not to happen is to get a tracked vehicle, but, I can't afford to get the perfect machine for each job.

From a design perspective I would either expect the hydraulic pressure that the pump can generate to be less than what can hurt the mechanical components and/or a pressure relief so that if there is kickback that thewheel would be allowed to move and not hold it's position until something breaks.

Did I beat on it too hard? I really don't think so, but don't know for sure. Latent manufacturing defects do exist. It does not really mature as either way, I get to pick up the tab.