B7200 hydraulic steering

[TheOldHokie]

Any reason I can't simply swap the steering arms (red and green arrows) from side to side ? I'll have to measure properly tomorrow, but they appear to be parallel (I would have expected them to be angled a little inwards). This would allow the steering cylinder to mount to the front of the axle as in a BX.

View attachment 170351

View attachment 170352

Not that it helps much but the OEM option was power assist not hydrostatic.

 

[Russell King]

@Paul Allwood

I don’t see how mounting the hydraulic cylinder where you indicated would work.

I believe it is supposed to be mounted transverse to the direction of travel. As I see it, you need to remove these two rods on the existing steering system.

The steering cylinder should replace the lower tie rod bar. But I am not that familiar with what you have and how it works really so I may be way off base. I think that the cylinder must be mounted rigidly and the rod has to move freely.

I believe the steering box will also be removed and that the controller will be mounted somewhere in that box’s position since the steering wheel must be connected to the input shaft of the controller (as I understand it).

 

[TheOldHokie]

@Paul Allwood

I don’t see how mounting the hydraulic cylinder where you indicated would work.

I believe it is supposed to be mounted transverse to the direction of travel. As I see it, you need to remove these two rods on the existing steering system.

View attachment 170364

The steering cylinder should replace the lower tie rod bar. But I am not that familiar with what you have and how it works really so I may be way off base. I think that the cylinder must be mounted rigidly and the rod has to move freely.

I believe the steering box will also be removed and that the controller will be mounted somewhere in that box’s position since the steering wheel must be connected to the input shaft of the controller (as I understand it).

Problem is the knuckles in a B7200 are designed to be driven from just one side. The steering box drives the left knuckle. The left knuckle then drives the right via the transverse tie rod. The double ended BX cylinder isnt well suited to that.

Dan

 

[Paul Allwood]

@Paul Allwood

I don’t see how mounting the hydraulic cylinder where you indicated would work.
.....

Thanks Russell, but I don't see why it wouldn't work. The long arm is pushed in and out by the existing mechanical steering box to push the arm on the steering knuckle back and forwards.

Replacing the mechanical steering box and this long arm with a hydraulic cylinder would do the same thing. If I go this way I just need to mount it so that an end of the cylinder is "fixed" with the rod allowed to move. Not as easy as mounting a single ended cylinder but I don't think it's impossible. And it still gives the benefit of even left and right steering.

 

[TheOldHokie]

Thanks Russell, but I don't see why it wouldn't work. The long arm is pushed in and out by the existing mechanical steering box to push the arm on the steering knuckle back and forwards.

Replacing the mechanical steering box and this long arm with a hydraulic cylinder would do the same thing. If I go this way I just need to mount it so that an end of the cylinder is "fixed" with the rod allowed to move. Not as easy as mounting a single ended cylinder but I don't think it's impossible. And it still gives the benefit of even left and right steering.

I dont think that cylinder changes length. The barrel is fixed and the rod shifts left and right pulling and pushing the two knuckles.

Dan

 

[TheOldHokie]

I would be tempted to go simpler.

https://www.steinertractor.com/CKS3869-Power-Steering-Cylinder

Dan

 

[Paul Allwood]

I dont think that cylinder changes length. The barrel is fixed and the rod shifts left and right pulling and pushing the two knuckles.

Dan

Yep. So if I fix an end of the barrel to a bracket I'll make, the rod will move in and out and push or pull the left side steering arm. I'll just need to allow the barrel to pivot but not move back or forwards with the bracket. Probably re-purpose one of the tie rod ends.

Maybe not the simplest, but I like to try and use the bits I already have.

 

[Paul Allwood]

Not that it helps much but the OEM option was power assist not hydrostatic.

View attachment 170354

This probably does help. I think it supports the case for fitting a cylinder where the above power steering cylinder goes. Do you know if there were any issues with the steering connections downstream from the cylinder on these power steering setups ?

 

[Paul Allwood]

@Paul Allwood
....

I believe the steering box will also be removed and that the controller will be mounted somewhere in that box’s position since the steering wheel must be connected to the input shaft of the controller (as I understand it).

Correct. The existing mechanical steering box and steering shaft gets removed. I'll either mount the steering control valve directly to the steering wheel or with a shaft between it and the steering wheel. Will decide locations when I pull that but apart.

 

[TheOldHokie]

This probably does help. I think it supports the case for fitting a cylinder where the above power steering cylinder goes. Do you know if there were any issues with the steering connections downstream from the cylinder on these power steering setups ?

The OEM system used a priority flow divider so nothing downstream

 

[torch]

Oh and you would use the Mid PTO pump to run just the loader.

I don't know if the B7200 is quite the same, but on the late B7100 the mid-PTO only works when the rear PTO is in the high-speed position. Could be a PITA if something was connected back there at the same time. Plus it's a unique spline on the shaft so some sort of adaptation would probably be required.

I think I'd rather adapt something to the front of the crankshaft and use that for power steering.

But as I said, I don't know if that applies to the B7200.

 

[Paul Allwood]

I don't know if the B7200 is quite the same, but on the late B7100 the mid-PTO only works when the rear PTO is in the high-speed position. Could be a PITA if something was connected back there at the same time. Plus it's a unique spline on the shaft so some sort of adaptation would probably be required.

I think I'd rather adapt something to the front of the crankshaft and use that for power steering.

But as I said, I don't know if that applies to the B7200.

I've already decided to mount whatever pump I ended up with on the front as I have a mid mount mower. Might swap it for a 3PL mower one day, but that's it for now.

 

[Paul Allwood]

The OEM system used a priority flow divider so nothing downstream

Sorry, I was thinking of the mechanical steering linkages. Wondering how they fared with the addition of the power steering cylinder.

 

[TheOldHokie]

Sorry, I was thinking of the mechanical steering linkages. Wondering how they fared with the addition of the power steering cylinder.

I have no direct knowledge of the OEM system but this issue has been debated on other forums.

The load on the steering components is determined by front end weight and ground conditions. Adding power assist does nothing to change that.

What PS does is reduce the amount of motive force the operator has to supply via the steering wheel. In the case of the B7200 the OEM system assist was applied at the steering link. That reduced the force going through the failure prone steering gear box which is a big improvement.

Dan

 

[North Idaho Wolfman]

Take the left knuckle and move it to the right, and vice versa, ditch the drag link and the tie rod and install the cylinder in the front of the axle.

 

[Paul Allwood]

Take the left knuckle and move it to the right, and vice versa, ditch the drag link and the tie rod and install the cylinder in the front of the axle.

View attachment 170398

Haha - glad you're keeping an eye on this and thanks for the suggestion....same as what I posted as a question above at post #60. Makes me feel good when someone who knows stuff makes the same suggestion as me.

 

[North Idaho Wolfman]

Haha - glad you're keeping an eye on this and thanks for the suggestion....same as what I posted as a question above at post #60. Makes me feel good when someone who knows stuff makes the same suggestion as me.

Dang, I read back 2 pages playing catch up, and that was one more page back on the 3rd page.
I think it should work, the B7100 uses the same setup, yet the drag link is in the rear and the tie rod is in the front.

 

[North Idaho Wolfman]

Do you have this part?

 

[Paul Allwood]

Do you have this part?

View attachment 170401

Nope. Looks like it should go between the steering control valve and the steering wheel but on the Messicks exploded view the steering wheel attaches directly to the valve shaft.

 

[North Idaho Wolfman]

Awww yes you have the orbital valve that already has the adapter on it.