Old style Ross on a M51

[M51clueless]

The wheels turn HARD Left as soon as I crank the engine

Had a bad hydraulic leak in my gear box, ended up buying a rebuilt one from Memphis Equipment,

The install went fair enough, the new unit did not come with the hydraulic control that mounts on the gear box, so transferred the old one on to the new gearbox.

soon as hydraulic pressure built up the steering turned hard left,
so far.
1 have re-purged the lines
2 removed the hydraulic control valve assembly, looked at it , seems ok
3 reinstalled assembly making sure the plunger was seated in the groove
4 adjustment of the control valve are where I think they should be based on the TM
5 tried reversing the hydraulic lines on the gear box and was able to get the steering to turn hard right.

Feel sure it comes down to an adjustment on the hydraulic control valve, just a a loss of how to do that beyond adjusting the nut on the valve assembly , which I have tried.

Looking for ideas Sure would help if I didn’t have to drive in a continuous left circle!

 

[US6x4]

Sure would help if I didn’t have to drive in a continuous left circle!

NASCAR does it and gets payed handsomely for it...

 

[BKubu]

I'd contact Memphis Equipment.

 

[M51clueless]

I'd contact Memphis Equipment.

Talked with them this morning, got some ideas to try,

 

[msgjd]

I believe your problem is in the actuator unit on the steering column and not the ross box .. Have not had your exact problem but one of my M51's has a faulty actuator unit.. It fights against a driver when trying to steer to right but steers normal otherwise.. Others in their threads on SS have had my same issue but theirs fights a driver when turning left ..

There are seals, plungers, and valve(s) inside.. I would imagine if a plunger is stuck full-open to the left-turn quadrant it would do what it's doing to you .. I decided if I was going to have to remove my actuator unit in order to have better access to monkey with it , I might as well buy a new one.. Which I did... Got a NOS unit for the early ross system on epay for a very reasonable price .. The guy had a few left, last I knew

 

[Robo McDuff]

I have a manual somewhere, I had problems as well and ended up combining two steering boxes.

 

[M51clueless]

Thanks Guys,
Hoping what Memphis Equipment suggested does the trick, Think I’ll have a chance to play with it tomorrow. My steering was working ok just leaving a visible trail behind the truck , you could track the old girl from the oil she was leaving . Anyway since my control valve seemed to be working before I messed with it figured the gearbox would be enough to fix it.
Not sure how easy or hard that shuttle valve is supposed to be to move, mine seems a little stiff.
If what Memphis Equipment suggested doesn’t work , will plan to get a new control valve.

 

[msgjd]

[QUOTE="M51clueless, post: 2556030, member: 99303"
My steering was working ok just leaving a visible trail behind the truck
[/QUOTE]

Playing devil's advocate: Let's pretend a fault of some sort in the actuator or the control valve is what blew out the seal(s) in your old gearbox, and this same fault is what's causing your new box to activate one way hard all by itself since there is no leak (yet) to alleviate that pressure.. This may be true if the leak in the old box was bad enough..

Another thought, what are the chances a paint chip or other foreign object entered the system during the changeout and has lodged in a valve seat

 

[M51clueless]

msgjd,
So I went to eBay and sure enough nos valve assembly for $95 plus $15 for shipping.
of course always looking for a better deal, call Memphis Equipment, they have one too, but used not rebuilt and they only wanted $500 usAmerican dollars, so have the eBay one the way, Hope to update next week one how well that worked .

 

[msgjd]

msgjd,
So I went to eBay and sure enough nos valve assembly for $95 plus $15 for shipping.
of course always looking for a better deal, call Memphis Equipment, they have one too, but used not rebuilt and they only wanted $500 usAmerican dollars, so have the eBay one the way, Hope to update next week one how well that worked .

mine is sitting on the M51's pass seat in its box waiting until time/weather to install it.. It's been waiting since last summer

 

[M51clueless]

So to update, finally ran out of excuses, got the new valve control installed. The truck then went hard right instead of left, managed to adjust the valve, you have to turn the valve from the end that has the cover plate on it. The valve is too wide to use a screwdriver and has limited access, had to fashion a tool to be able to rotate the valve to adjust it. Finally got it to the sweet spot where the steering wheel had equal assist left and right .
Now the lesson,
I put the cover back on and started adjusting the castle nut on the other end. (11/16 Nut) Kept spinning it expecting it to tighten up against the valve. DID NOT REALIZE I was spinning the valve and screwed up the valve adjustment that had taken so long to get right.
Did manage to figure it out and get it back to the sweet spot and tighten the castle nut down while holding the valve in place from the othe end.

now on to the leaking front axle seal

 

[Robo McDuff]

Yes, getting a messed up steering working perfect on an old truck is tricky. Mine is not yet perfect, I will try that valve adjustment trick as well.

As to the seals, there are several good threads on that, also under brake repair. I did mine some years ago, added that experience to an existing thread; never came around to a good write-up (I think).