JD 1650 Steering Hydraulics Working Against Me

[Rofflesaur]

Hi, sorry if this is in the wrong section, I figured other makes of tractors and machines have similar hydraulic steering setups. I'm working on a John Deere 1650 tractor. When first started, the power steering works fine, but after about 10 seconds or so it is very difficult to turn to the wheel. Sometimes there's a shudder as your turning the wheel (loose, tight, loose, tight, etc). I lifted the front axle off the ground with a fork lift, and checked the bearings and tie rod ends. With the steering gear disconnected, the the front wheels turn left and right very easily by hand, so no issues up front. I reconnected the steering gear and turned the wheels with the tractor off. There's no binding or resistance and the wheels can be turned from stop to stop with one finger. I then started the engine, and at idle the steering becomes difficult, but there's no shudder like there is with weight on the axle. As I increase the engine RPMs the steering becomes progressively more difficult to operate. It takes slightly more effort to turn the wheel right than it does to turn it left.

Since the steering gear works perfectly with the engine off, I'm almost sure there's a hydraulic problem somewhere. Perhaps a blockage in a return line or a malfunctioning valve in the gearbox itself? I also noticed hydraulic oil being pushed out from behind both of the rockshaft arms, which seems to have started around the same time. This happens all the time, without even using the hitch.

I'm trying to locate a pressure test / flow meter set to borrow, but for the time being i'm just guessing. I don't want to just start throwing parts at it. Any advice is greatly appreciated. Thanks.

 

[Tx Jim]

I think you need to acquire a JD tech manual of which I have not. I'll guess that it's possible that parts keys #35 & 36 have failed.

 

[Zebrafive]

I'd start with the basics first.
Check hydraulic oil level/condition
Change the hydraulic filter Key 12
Clean or replace the suction filter/screen key 10

 

[Rofflesaur]

The hydraulic oil level was fine. I drained the oil and removed the filter screen in the rear. The oil was very dark and full of very fine dirt particles. there's quite a bit of small silver metallic pieces stuck to the screen. There's a few gold/brass ones. You can see the color of the old oil and filter screen in the picture below. I'm trying to locate a tech manual now.

 

[Zebrafive]

Did you replace the spin on hydraulic filter? It might be plugged.

 

[Rofflesaur]

I'm going to try and locate one on Monday in Fram or Wix. My local JD dealer didn't have one on the shelf. They are undergoing a change in ownership.

 

[Rofflesaur]

So, I cut apart the old filter and inspected the fiberglass element. It was 100% restricted with fine particulate matter. I got a new JD filter from the dealer (finally) and refilled with fresh Hy-Gard. I was all ready to start taking the steering gear out. I started it up and let the new oil circulate, and the steering worked great! Who would of thought? No more leakage around the rockshaft arms either. I'm going to change the filter again after running it a little. I'm sure there's more dirt in there that didn't come out when I drained it.

 

[Zebrafive]

Thanks for the update, sure to help others with same problem

 

[retro7570]

If this tractor has wet brakes, the stuff you found in the filter may be brake lining. I would check the hyd fluid again in a couple days.

 

[Rofflesaur]

Internet says it has "differential hydraulic wet disc". Is this a byproduct of normal wear, or should I be concerned? I'm not sure when the last time the hydraulic oil was changed, if ever. Haha.