orbital valve

McCracken

McCracken

Logan Can't See This
Joined
Jul 9, 2005
Location
With your mom at a nice seafood dinner
how many have here have worked on one? I'm been doing some research and haven't found anything on rebuilding one of these or tearing into one. I searched pirate and found Billavista's articles but he doesn't have the Danfoss orbital schematics. I also checked with a local company that said it would be cheaper to replace the whole unit :confused: I can't see what could go wrong besides a few o-rings.

what happened was that I hit a log on the side of the trail. The next thing I know the steering won't work when I turn to the right. Left is fine but right is not. It's like you hit a brick wall.

Anyone have a clue?
 
Ya, it's broke.

Pm me the numbers on your oribital & I'll cost one for you.

You don't have the tooling & fixtures to re-build one. Your better off to replace it.
 
We tried rebuilding two of them. Neither attempt was successful.

Your log encounter probably dislodged some crap from someplace in the system... maybe a bit of o-ring from the ram or a piece of impeller from the pump, which then tried to cycle through the valve and either got jammed in a passage or scored one of the surfaces enough to cause internal bypassing.

You might.... MIGHT get lucky by pulling it apart and removing the offending bit. But treat it more like a research project. They're kinda cool inside.

Make sure you put multiple filters in the new system once you get it all back together. I like one before and one after the pump. One of them can be a big screw-on if you want, but the other can just be a small inline hydraulic filter.
 
I spoke with Lance at PSC yesterday and he said to tear it apart. So I did. I found nothing in there. I didn't see any chunks or scratching in the orbital. He claimed that hitting a log wouldn't have done anything. He said in Texas they jump their rigs and he thinks it would be rare to mess one up this way.

I also replaced the TREs (just in case and they needed it). Took the ram apart and cleaned it and put it back together. I took compressed air and blew out the lines and put it all back together.

It steers perfectly when it's up in the air. Left to right is great but once I put weight on the tires it turns slow and needs more pressure on the wheel than I remember. I'm starting to think it's all in my head but I don't think so. I really do think it turned better before this happened.

Lastly, I noticed my tie rod is slightly bent. It doesn't rub on any of the components when I steer but is bent in slightly and up.

edit: I also called Western Carolina Forklift and Carolina Hydraulics and they both gave me the impression that it's cheaper and easier just to buy a new one.
 
When the engine rpm is up does it get easier to steer? what is the cu. of your oribital & what pump are you running? Have you modded your pressure & flow? Does you oribital have a built in relief or are you using the relief in your pump?
 
The pump is a stock saginaw off of my 360. I did the west texas mod to it so I think it should be fine. The valve is a Danfoss unit. I'll have to get the numbers off of it tonight. This set up has never failed me until now. I've never had to rev the engine to steer better. I guess I've been lucky.

The only thing I can figure is the tie rod got bent a way that makes it harder to steer when the weight of the rig is on the ground. That sounds dumb to me but it's all I got.

To be perfectly honest I need someone else to steer this thing and tell me what they think.
 
Jeff, here are the numbers off my Danfoss.

OSPC 100 ON
150N2039

*449D2429*

edit: The orbital is busted. I borrowed one off of a friend of mine's rig and it turned like a champ. No hesitation, no pressure, nothing but smooth spinning.
 
orbitals ARE rebuildable, most places do not rebuild them as the time to do so VS the risk if it's not done right is close to if not more than the cost of a new unit.
If you are not careful, an orbital will turn into a hydraulic motor, in many cases spinning wildly ( not good if your hand happens to be in the way, this is the risky part, it don't take but one miss placed spring )
That being said, I have "re-packed" an orbital before, there are a lot of small parts to keep track of. The one I worked on was a stacked plate style on a Hyster Forklift. I was real nervous when I started the engine for the first time and kept my hand out of the wheel until I was sure it wasn't going to go crazy on me. Knowing what I know now, I'll just replace it next time ( 2.5 yrs., no leaks or issues :huggy: )
 
Blkvoodoo said:
orbitals ARE rebuildable, most places do not rebuild them as the time to do so VS the risk if it's not done right is close to if not more than the cost of a new unit.
If you are not careful, an orbital will turn into a hydraulic motor, in many cases spinning wildly ( not good if your hand happens to be in the way, this is the risky part, it don't take but one miss placed spring )
That being said, I have "re-packed" an orbital before, there are a lot of small parts to keep track of. The one I worked on was a stacked plate style on a Hyster Forklift. I was real nervous when I started the engine for the first time and kept my hand out of the wheel until I was sure it wasn't going to go crazy on me. Knowing what I know now, I'll just replace it next time ( 2.5 yrs., no leaks or issues :huggy: )
Click to expand...


come on Kev you could get matching sets again....
 
dude, I'm already spooked, I just got back from Charlotte tonight......
 
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