4320 Power Steering

sunnyside360 · May 7, 2011

Have a one year old JD 4320 with 130 hrs and started having this intermittent power steering problem. It will turn left just fine as it has always done but when I turn right the steering wheel will not budge. Turning the wheel left and right will usually overcome the problem. It's done this about 6 times in the past four months and it always happens when trying to turn right just after making a hard left turn with the FEL bucket full. The hydraulic fluid dip stick indicates full.
Looking for ideas as to what the problem is or could be. The tractor is under warranty but I'd fix it myself if it is simple.

jd110 · May 8, 2011

There are many factors in play here. Since the problem only occurs when steering right with a full bucket, it seems as if something in the steering cylinder or axle may be binding. I would raise the front of tractor off of the ground and steer back and forth with the engine off to see if you can isolate anything binding. If that checks out, then I would get a hydraulic pressure gauge and tee it into the pressure line of steering for right side. Then try to place the front wheel up against a large tree or other immovable object and steer to the right and see what pressure reading you get. The relief valve should be set to 1500 psi. If nothing is binding and pressureis good, then you are simply asking the steering to do more than it is capable of. Adding more ballast to three point hitch can help counteract weight on front axle. Do you have any ballast? Fluid, rear weights, ballast box? How much weight are you lifting when problem occurs? What kind of tires do you have? What type of surface are you operating on? Concrete, blacktop, hard packed dirt, loose dirt, mud? narrower tires sometimes steer better since there is less friction of tire on ground. Like I said before, lots of things to consider here.

sunnyside360 · May 8, 2011

jd110 said:
There are many factors in play here. Since the problem only occurs when steering right with a full bucket, it seems as if something in the steering cylinder or axle may be binding. I would raise the front of tractor off of the ground and steer back and forth with the engine off to see if you can isolate anything binding. If that checks out, then I would get a hydraulic pressure gauge and tee it into the pressure line of steering for right side. Then try to place the front wheel up against a large tree or other immovable object and steer to the right and see what pressure reading you get. The relief valve should be set to 1500 psi. If nothing is binding and pressureis good, then you are simply asking the steering to do more than it is capable of. Adding more ballast to three point hitch can help counteract weight on front axle. Do you have any ballast? Fluid, rear weights, ballast box? How much weight are you lifting when problem occurs? What kind of tires do you have? What type of surface are you operating on? Concrete, blacktop, hard packed dirt, loose dirt, mud? narrower tires sometimes steer better since there is less friction of tire on ground. Like I said before, lots of things to consider here.

The tractor has R4 tires. All four have RimGuard for ballast and nothing attached to rear 3 pt hitch. The steering issue has been happening while putting gravel along the sides of my asphalt driveway (tractor on asphalt). It has also occurred while using the grapple to move brush (not nearly as heavy as gravel in bucket) along edge of field on hard packed dirt. I plan to do some bush hog work this week and should know if FEL is a factor. I don't believe the tractor is being over stressed as I've used it many times exactly this way in the past year.

Another TBN member (phj) suggested checking the hydraulic connections on the power steering cylinder with the possibility of air getting into the system. I did get about a half turn on the left fitting. The right fitting was very tight. I then ran the tractor for about 2 hrs putting more gravel along the driveway this evening and the problem did not occur. Is the problem fixed? Hard to know because it is very intermittent. Will hopefully know with more seat time this week.
Many thanks for your thoughts.

kennyd · May 9, 2011

Even with the Rimgaurd, you still need weight on the 3PH. The weight needs to be BEHIND the rear axle to effectivly take weight off of the front axle. Think of a see-saw, you want the "fulcrum" point to be the rear axle and not the front axle. If you read the loader manual it spells it out quite clearly.

om21braz · May 9, 2011

kennyd said:
Even with the Rimgaurd, you still need weight on the 3PH. The weight needs to be BEHIND the rear axle to effectivly take weight off of the front axle. Think of a see-saw, you want the "fulcrum" point to be the rear axle and not the front axle. If you read the loader manual it spells it out quite clearly.

+1 I had similiar experience before I placed a HD 6' box blade on my 4120. Loaded tires help some, but working with med. heavy/heavy loads in the bucket - ballast of some form behind the rear axle is a must.
P.S. Your front axle, seals, bearing, etc. will thank you for the ballast.

sunnyside360 · May 9, 2011

It's looking more like tightening the hydraulic fitting on the left side of the power steering cylinder did the trick. I ran the tractor several hours today w/o any steering failure --- FEL work and stone rake. I'm hoping the issue is resolved but only time will tell.

I know it's best to use weight on the 3 PH for ballast when using the FEL especially for safety reasons, and it lessens wear & tear on the front axles. I do hook up the rear box blade for bigger jobs. However, this intermittent steering problem was occurring also when using the grapple with fairly light loads and it did it once or twice when pushing snow with the FEL blade. I do not believe the problem is/was due to lack of rear ballast.