4610SU rear axle clunk

ETD66SS · Feb 28, 2017

Last weekend I was doing some brush hogging, I normally wear ear plugs when doing this, so don't hear some sounds. When I got done I parked the tractor for the day. A few days later I wanted to move the tractor as well as disconnect the brush hog.

I didn't use ear plugs because I was just moving it a short distance. When I started driving, not only did I hear a clunk in the LH rear axle, but I could feel it as well. It was a pretty good metallic clunk, once per revolution of the rear tire. I was driving with the brush hog's rear wheel down, I thought maybe that was it, so I lifted it completely off the ground, that didn't resolve the clunking sound.

Next I tried engaging/disengaging the differential lock, still hear/felt the clunk. Then I slammed on the brakes a few times, still had the clunk. I drove to where I wanted to drop off the brush hog, so I removed it and did a test drive, the noise was gone.

I don't think this was a noise that had anything to do with the brush hog, the PTO was off, and it didn't feel/sound like a noise coming from the lift arms or anything like that.

I can't replicate the noise now, and I guess it has me a bit freaked out as to what it could be. It really did sound/feel like a deep mechanical/metallic clunk coming from the LH rear axle housing.

Any ideas?

RickB · Feb 28, 2017

Check your rear wheel disc to axle and rim to disc hardware. Something is loose and chucking around.

Shaneard · Feb 28, 2017

So it did it with the bush hog attached and then didn't do it after unhooked? Could it have been your PTO was turning just a little bit making the bush hog turn a little bit and when the blades got to a certain point they were clanging? I've seen it happen on other tractors. That's the only thing I could think it would be since the noise was gone when the bush hog was gone.

ETD66SS · Feb 28, 2017

Shaneard said:
So it did it with the bush hog attached and then didn't do it after unhooked? Could it have been your PTO was turning just a little bit making the bush hog turn a little bit and when the blades got to a certain point they were clanging? I've seen it happen on other tractors. That's the only thing I could think it would be since the noise was gone when the bush hog was gone.

Yeah, I will first check the rims. I did check to see if it was the blades on the brush hog, but they were not moving.

But yeah, I was not able to replicate the noise once the brush hog was off...

I certainly did not beat on the tractor at all the last time I used it, there were no "incidents". So hoping it is something simple.

Ford850 · Feb 28, 2017

Rick is right, check the hardware for a loose bolt etc. The extra weight of the hog could be enough to cause the shift/clunk on a wheel. I had a similar issue years ago and swore it was internal. Turned out to be under torqued bolts on the ez adjust rims of mine.

ETD66SS · Apr 21, 2017

I finally got the time and weather to check center disc bolts, many of them were loose. So thanks for the tip.

Now, is there a better type of nut to use so they don't come loose? Can I use nylock nuts or deformed head nuts? I don't see why not...