4720 steering is jerky

[qstott]

I didn’t have a chance to run the tractor long enough to really get it hot today. But, I’m sure I have improvement or maybe even complete success. I removed the screen from the filter housing and it didn’t have any gunk in it that I could see. However, the screen appeared to be sucked flat and collapsed. I opened it up carefully with a small screwdriver and punch. Cleaned everything and put it back together. The few minutes I was able to run it, there was no more jerkiness. The proof will come next time I give it a good workout. Thanks for the helpful tips!

 

[arlen4720]

I didn’t have a chance to run the tractor long enough to really get it hot today. But, I’m sure I have improvement or maybe even complete success. I removed the screen from the filter housing and it didn’t have any gunk in it that I could see. However, the screen appeared to be sucked flat and collapsed. I opened it up carefully with a small screwdriver and punch. Cleaned everything and put it back together. The few minutes I was able to run it, there was no more jerkiness. The proof will come next time I give it a good workout. Thanks for the helpful tips!

That’s great! There was another guy I remember had his collapse also. I don’t know how that happens, but I think I would replace it. The last thing you want is for that screen to start disintegrating. That would send fragments right into the hydrostatic transmission.
Just theorizing as to a possible reason for collapse…Since that line supplies charge flow to the eHydro system, I wonder if there are times when the hydro pulls a vacuum and the power steering pump can’t keep up with the charge flow. Maybe that causes that filter to collapse. Do you drive around at (or close to) idle sometimes? Maybe bumping the throttle up a bit would help. I like to have the engine running at around 1500rpm minimum.

 

[qstott]

I don’t usually run it near idle. When it starting getting much worse I was mowing and running about 2500 rpms. It’s a head scratcher for sure.

 

[beenthere]

Hope you have a new screen coming soon. It sucked closed for a reason, I'd guess. And that debris that caused it to close, may be going down the line now to who-knows where.

 

[Brown Dog]

My 4720 open station I sold did this same thing.
best I remember it was a hex shaped filter about 3” long I washed the contamination from & fixed the issue.

 

[oldtimer 66]

Some times hydraulic filters get sucked down is because there is moisture in the hydraulic system. In the winter time when the water in the hydraulic system freezes/ crystalizes/ these crystals plug the filter and collapse it. It might not be a bad idea to change your hydraulic fluid. Just a suggestion.

 

[qstott]

I just mowed for about 30 minutes and every thing worked fine! I do plan to change fluid and filters soon.

 

[Richard]

Good that you evidently fixed your issue.

My backhoe was fighting me at one time. Cutting to the end, what turned to be my issue is the seals in the steering cylinder were starting to leak. This allowed the pressure to squeeze to the other side and nullify some of the push that the pressurized side was trying to do.

Rebuilt cylinder and that fixed that issue. Looking at the cylinder would have probably never crossed my mind....it was my brother in law who brought it to my attention.