steering creeping

[toomanymachines]

So I just had my new to me loader delivered. I know it had some issues, and now I need to fix one that I consider rather important.

the steering creeps to the right. You have to constantly turn left to maintain a striaght line.

I have the shop manual and it tels me only exactly what I thought. One the steering box has failed. and need new overhaul kit . or two. the cylinders have internal leaks, one or both.

Does anyone have experience with anything like this. it is a 2002 komatsu with just over 7k hours.

I dont want to tear anything apart if I do not need to.

I have rebuilt a burnt tractor and have rebuilt a steering box before. not the end of the world.

I was thinking if the hoses are long enough to swap from one sylinder to the other, I could swap them and find out if it creeps the other way. if it does that I would assume it is the steering box. If it still creeps the same direction it would have to be a cylinder.

thanks in advance for any suggestions or advice.

 

[stondad]

If the machine is stationary, engine running, and it wants to turn, it would be the steering control valve.

You don't say what model Komatsu it is but we must clarify whether it does have a "steering Box" where it will have a follow-up link and a linkage to a spool valve. More likely it has round looking "orbitrol" type steering valve which will be at the end of the steering column and have four hoses to it.

In the orbitrol case, if you are standing still and articulate the machine fully to the stops and you can still turn the steering wheel, you have blown seals on a steering cylinder. This may only happen in one direction.

Which one? Better to do them both.

If it has a real steering box and the linkages, you may get away with an adjustment.

Be very careful if you are in the articulation area with the engine running. It could crush you if it turns by itself or because of you adjusting it.

 

[toomanymachines]

'02 wa 180.
Does not twitch at standstill, but as soon as you move it tends to drift over to one side. If you just try to crank it ovwer when it is standing still it takes more revelutions of the wheel to one side than the other.
It make total sence that one of the piston seals in the cylinders are damaged or blown.
Yes it does have an orbital style pump at the bottom of the steering coloum.

I guess I should get ahold of komatsu for a couple of seal kits

Is anyone aware of a reasonable priced mailorder place for komatsu parts?

 

[stumpjumper83]

What stone is saying is that if you can still turn the wheel after it hit the lock, not just revolutions of the steering wheel from centered. Another thing to check is tire size and pressure, missmatched tires can make things goofy.

 

[toomanymachines]

I did the testing this afternoon. full left, you can keep spinning the wheel with not too much extra effort. Full right, you can also keep spinning the wheel but it requires alot more effort.
So I guess it is safe to assume that both cylinder internals need rebuilding. One is just leaking much worse than the other.

Unfortunatley I also found that my front right tire had a leak. peice of leaf spring u clamp. But My 1" impact will not budge anything. I guess I will need to heat all but one bolt.

 

[stondad]

Hi Mate,
You have come to the right conclusion, you have to reseal both cylinders. Just because it is worse one way than the other doesn't necessarily mean its only one cylinder or the other because the pressure oil is seperated from the return oil by the seals on the pistons of both cylinders. Maybe only one is leaking badly but the other one wont be far from doing the same.

Good luck with your wheel nuts. Sounds like the long piece of pipe for you!

 

[toomanymachines]

I was jumping up and down on a 4' peice of pipe and nothing would budge. I weight about 240 lbs. so that should be at least 1000lb torque.
I think Mr. firewrench may be needed.

 

[stumpjumper83]

carefull heating nuts on rims, there is a posting on here about why you shouldn't weld on them, can cause severe explosion. I'd try a longer piece of pipe fist. Or check the air pressure supplies to the gun, a difference of 20lbs of air makes the gun act like a whole new animal

 

[stondad]

Tell me if I'm being a smarty but you know that some machines have left hand thread on the left side wheels.

Yours may have had left hand studs put on the right (wrong) side sometime????

Any way, our tyre service would probably be doing the tyre repair with the rim still on the loader or maybe you don't have that luxury where you are.

 

[toomanymachines]

I actually have a tire shop and have 160 psi on a 3/4" hose feeding a 1" gun. I want to take it off becasue I have an italian tire changer that handles from 20" rims up to 42".
Looks like this one

I hope the picture works.

 

[stondad]

Wow! The picture worked fine. Please excuse me. I can see that you certainly know what you are doing there so will leave it to you.

Actually There was some discussion on the Forum the other day about torque multipliers.

 

[toomanymachines]

well got the wheel assm. off today, second 1" impact with a shorter shank (anvil) only two needed a little heat. will antiseize them and install with a 3/4 drive.
tire had about 4 gallons of slime. but got it fixed up after I let it drain to the bottom. Now to waite for better weather 70k winds and minus 10C is not that nice of a day.

 

[stondad]

Glad you are sorted with the tyre and wish you good luck with the steering.

Writing this to you at 6 pm wearing nothing but speedos and going in the pool soon. Oh yeah, beer too.

Cheers and you folks in the cold are legends!

 

[toomanymachines]

bringing up this old tread, got the two cylinders out and rebuilt. both had bad internal seals. rebuilt them and reinstalled.

Still has bad steering. full right and it locks up. crank it full left and it (steering wheel) keeps turning. Dig into a pile and it will not even keep the machine straight, crank hard left.
I do not think that I could have damaged the cylinder when rebuilding it. They both went together rather well.
I guess I could change the hoses around at the orbital control at the bottom of the steering column and see if it does the same in the other direction. I know I did not waste any time on the cylinders, as the seals were pooched.

 

[willie59]

If you could switch the output lines at orbit valve, would prolly telly you a lot. Also, if you could cap the output ports of orbit valve, shouldn't be able to turn wheel at all. If wheel will turn left with ports capped, bad orbit valve.

 

[toomanymachines]

Just remembered something else. Does the system have some sort of bypass valve? You can hear the system squeal when you go full lock to the left. The kinda noise you would get when the bypass squeels? I would think that it may have some sort of pressure bypass valve? maybe the spring is broken or slacked off?

 

[willie59]

Anything is possible toomany. Simply follow your two output hoses from orbit valve to steer cylinder. I know, that's easier said than done, but it's do-able. If hoses don't connect to some form of relief manifold prior to connection to steer cylinders, then problem is either cylinders or orbit valve.

 

[oldseabee]

Not sure about the Komatsu, but Michigan loaders had steer stop valves in the hinge area that bypassed the steer pressure in almost full steer to prevent banging into the steer stops, could be one of them is leaking, if they are on your machine.

 

[toomanymachines]

I thought I would let people know what I have figured out. I checked the cusion valve and found nothing, put in some new o rings to make sure. I ended up swapping the lines off of the steering motor. to see if the sides swapped or if they behaved the same. Everyhthing worked just the opposite. So I now know that it has to be bypassing in the char lynn steering motor, as the cylinders are not the problem.

 

[willie59]

Thanks for the post TMM, be sure and let us how it sorts out.