******Second Jinma 554 Steering Failure*****

[doxford jim]

Hi,

Some of you may know that I had a steering failure on my 2007 Jinma 554 tractor about four weeks ago - the left front wheel steering knuckle broke at 30 hours, where the power steering cylinder rod end bolts on to it. Well today, I had a second failure of the replacement part, which broke after just six hours of use.

I was clearing snow (piled from passing snow plows) at the entrance to my property on the highway when the **** thing broke. A job I do all the time with my 1959 2WD MF-65 and have never had a problem. Today I used my 2007 4WD, 55hp utility tractor and it broke - aw s--t!

Sorry, but I am a little p----d off at what happened. When I put the new replacement part in, I was careful and made sure that the tierod was straight, the toe in was within specs and all joints tight. The snow clearing work I was doing was exactly what I would do with the old Massey and yet the new Jinma part failed - bang, just like that.

I am sure that there has to be either a material problem or a design fault. A cursory glance at what I could see gave me that the tie-rod was bent, the end parts loose and one steering connection loose. This is not rocket science and a major steering component failing frequently is not on.

Incidently, I replaced the tie-rods and ends on the old Massey two and half years ago, adjusted as per specs (toe-in etc) and have had no problems - on a tractor nearly 50 years old.

I will cool off overnight and have a good look tomorrow. I am sure the problem has to be material and maybe design geometry or similar.

Anyway, I was able to get the tractor off the highway, up the drive and into my workshop - took me two hours to do it though. That is a big plus in itself as I was working on my own again

Will update you guys as things come to light.

However, any of you out there that already have, or have ordered the new Jinma 554 tractor - be careful of your steering components. Especially the left front wheel steering knuckle. My first broke at 30 hours, the second at 6 hours.
Jinma is going to get a lot of emails at photographs from me - I can tell you.

Jim

 

[3RRL]

Jim,
Sorry to hear about the second failure man!
I mentioned on the other threads about reinforcing the casting piece which projects way out there. Hope you still have that original casting to try that on. You can weld 1/2" plate and/or gussets to that arm that sticks out. It looked like a weak spot to me when I saw it. The 554 front drive and tires are big and heavy and IMHO, the casting arm connection is not adequately designed to take the stress.

 

[bluechip]

to take some of the load off that part, you might want to try to adjust the steering linkage so teh cylinder stops before you hit the hard stops. Keep in mind I know absolutly nothing about the JM554, but if you hold the steering against the stop, the cylinder is still pushing full force. Also if you have a pressure relieve valve in the system (it is on the engine mounted steering pump on a KAMA) you might try backing out the adjustment so the max pressure is reduced. Bear in mind this could limit steering power in situations when you have the front wheels down in the dirt and try to steer, so be very careful. I don't think there are many JM554s in the US yet so cant tell if it might be a part design problem or simply a set up adjustment. Since you had to pay for the part, I'm guessing you are out of warranty, but it still wouldn't hurt to check with your dealer/broker so word can get back to Jinma about this problem.

 

[doxford jim]

Chip, Rob - thanks for your comments, much appreciated.

As far as the stops go on the hub, I don't think the wheel turns far enough around to meet them. Having said that, is it possible to get the front tie rod on backwards (it looks like it can only go together one way). I do know that the new tractor was doing the same work that I have been doing using my old 1959 MF-65 ( and the massey did it fine without problems).

Also possible that I may have not got the settings correct, though I thought did check them carefully. The fact that the part could fail suddenly like that - bang, without warning, is not good. I do think the cast material has something to do with the failing. Incidentally, the ambient temperature was +4C and spring like weather for a change.

I will go down and check it out later and let you know what I find.

Just thought it important that other owners of the Jinma 554 be aware of possible problems and to double check their steering parts and measurements.

Jim

 

[doxford jim]

Hi Guys,

I think I have found the cause of the problem.

I worked on the tractor this morning and checked everything out that might effect what happened. Lifted the front up so I could work on the wheels ok. Removed the bowed tie-rod tube and straightened it as best I could. Reassemble the linkage and adjusted the toe in to 10mm at front (specs call for 4 - 11mm). Turned the wheels hard over to the right so the mechanical stops made contact and then lowered the tractor to the floor. I then checked to see how far the power steering rod end would travel when hard over by turning the steering wheel. Well, the rod end went almost 1/2" further than the control arm. In other words the ram was trying to move the arm after coming up to the mechanical stop.

I am pretty sure this extra motion is what has broken the control arm. Adjusting the ram stroke will eliminate this problem - I hope. I don't know where the system pressure relief valve is just yet (for the steering system) so the travel adjustment should work just as well.

So, you guys out there that have purchased the new Jinma 554 tractor, make sure you check the power steering rod end movement. Too much travel will cause the small control arm to break and you will loose your steering.

You can see what I mean with the extra travel, in the attached picture.

Hope this helps someone else from getting similar problems.

Jim

 

[schmalts]

I would think this to be normal for the cylinder to be able to over travel the stop. I would take Chips advice and lower the pressure regulator for the steering pump pressure.

 

[bluechip]

Adjusting the pressure and/or the travel of the cylinder are only to help protect a part that may be too weak to do its job. Normally, as Schmalts says, the cylinder should be able to turn to the stop. The color of the break makes it look like it may be a defective casting, perhaps a bad batch from the foundry.

 

[Flyhiflylo]

I will check travel on my rig...

 

[doxford jim]

Adjusting the pressure and/or the travel of the cylinder are only to help protect a part that may be too weak to do its job. Normally, as Schmalts says, the cylinder should be able to turn to the stop. The color of the break makes it look like it may be a defective casting, perhaps a bad batch from the foundry.

Hi Chip,

Thanks for your comments - much appreciated.
The tractor is still under the parts warranty from Jinma - I only got it at the end of October 2007. I paid for the first replacement as the importer (I bought a crated deal) was slow in getting to Jinma. I ended up contacting Jinma myself and got almost immediate reply and the new warranty part was sent by airmail (DHL) yesterday. I am guessing a week to reach me, maybe a little more.

When I contacted Jinma I did say that I was concerned that the material or design could be faulty and that I was concerned about the component reliability. When you lose that component control you have no steering. They did not comment on my concerns, who knows maybe someone over there is actually interested in customer feed back - I sure hope so. I was hoping this warranty replacement would be a spare to gather dust on the shelf in my shop

And, yes, my intention of adjusting the steering ram stroke to "just enough" is to protect the part from further damage. I will look on the steering pump to see if I can find the pressure relief adjustment and also turn it down a bit as well.

Seems a shame as the tractor otherwise, seems a nice unit. I don't think the Jinma is the equivalent to the Kama, but for my needs, should be enough - if no more steering problems.

mariner

 

[Diamondpilot]

I would have the other 2 broken pieces welded and maybe beefed up for spares.

Chris