POWER STEERING WON'T TURN LEFT UNDER LOAD REPLACEMENT PARTS NOT AVAILABLE

[tomcat7359]

Thumbs up Farm, I do not see any reason why your modification would not work or give you any future problems. The slight difference in cyl size would not be any problem at all in my opinion. If the new cyls are slightly larger bore, your steering will slow down, but you probably would not even notice the slight reduction in speed. Some might say the larger cyls will put out more force, and that is true, but you sound like an intelligent man, and I bet you have already considered this fact. You could always set your steering pressure down a little bit to lessen the force, but I really doubt it would ever be an issue...
I think you are on the right track...

 

[Thumbs Up Farm]

I didn't mean it would come back to center by itself. When it's turned to center the wheel is in the same spot as it was before you turned it.
The shaft takes up room in the cyl and the oil on the outside of tube makes up for your shaft.

Ok, I wasn't sure. This could be an issue, thanks for pointing it out. I seem to remember reading somewhere that someone else had a speed knob on their steering wheel for a hydrostatic system and the wheel never came back to the same place anyway. I have never paid attention to that because I have no speed knob and the only thing I might notice would be the position of the center cap logo or the steering wheel spokes. Neither one really matters to me, I just want an easy smooth steering that turns in both directions

My parts should be in today. So, maybe I will have time after Christmas to do the install and test everything. I will post back on here when finished so the next guy will have the info.

Thanks everyone and Merry Christmas :dance1:

 

[Thumbs Up Farm]

Thanks tomcat, yes I did consider the new cylinders might have slightly larger bore and thus more power. That would be good. I selected these cylinders because they have a slightly larger rod than original (1"vs 7/8"). The bigger rod gives me more meat to drill and tap for the tie rod end, and is less likely to bend under load, but reduces pull back force. The only other option was a 3/4" rod. I believe those would work also, but the internal design of the cylinder seemed cheaper, the port fittings were not the same as my original, and the pressure rating was lower (2000 vs 3000psi). The pump relief is 1500 so should be OK.

My only worry on the force is that these don't have as much as original, that would be bad and the 3/4" shaft would have been a better choice. I have already pulled the trigger on my choice, so we will see.

 

[tomcat7359]

I doubt you will see any difference from the larger rods and bores.. Personally I would like the larger rods for strength, steer cyls rods can be prone to bending. The cyls work together in unison, so the smaller effective area on rod side, will be "helped" by the larger bore from other cyl... So it works out.

 

[Thumbs Up Farm]

I doubt you will see any difference from the larger rods and bores.. Personally I would like the larger rods for strength, steer cyls rods can be prone to bending. The cyls work together in unison, so the smaller effective area on rod side, will be "helped" by the larger bore from other cyl... So it works out.

That is what I am counting on. The O.D. of the old cylinders is 2.125 the new is 1.875. So there is 1/4" difference in O.D. but I think the sleeve design would take up that 1/4" and be the same bore. I figured since this machine has a bigger cylinder rod than all the other similar sized tractors, that bending may have been an issue when they designed the tractor which is another reason I went with the larger rod.

THANKS AGAIN EVERYONE AND MERRY CHRISTMAS!!:dance1:

 

[Thumbs Up Farm]

A cylinder that is bypassing will heat up. Hold the wheel to the left for awhile and then check the cylinders to see if one is hotter than the other. The hotter one is bypassing.

I would take the cylinders to a local hydraulic shop and get a quote for rebuild or replace. Tell them your concerns about the swelling. They can rebuild you cylinder using the same rod/piston and just give it a new new tube in the same configuration. Probably for cheaper than a whole new unit that you'll then have to mess around with. The rod is the expensive portion of the cylinder.

Good info on the cylinder heating up. :thumbsup: I have been using the tractor waiting for my parts to come in and decided to feel of each cylinder for heat. Sure enough the RH cylinder is warm the LH cylinder is cold. This confirms that the RH cylinder is bypassing causing the tractor to not steer to the left under a load.

 

[IceStationZebra]

This type of steering is very common on off-road equipment like 4WD tractors, articulating loaders, forklifts, combines, etc. Just Google "orbitrol". These systems never return the steering wheel to the exact same spot when going straight except in rare instances where a make-up system is included. (I helped develop one such system for an industrial forklift for Asian markets. We monitored the steering wheel vs. kingpin angle with the chassis computer and kept them in synch by turning on a make-up valve.)

Also, I agree about the control assembly being the unlikely culprit. The only failure mode I can think of that would result in one-sided steering like you describe would be for the control spool to be partially siezed or some odd debris. Both pretty unlikely unless the system was recently serviced.

ISZ

 

[dangreneau]

I think you shoud also check the knuckle bearings and bolts on the left side.

 

[texasjohn]

I think you shoud also check the knuckle bearings and bolts on the left side.

welcome to tbn