Full hydro steering issues

[Frodo]

A friend of mine has a 2002 F-250 with a 6.0L Powerstroke on 2006 Superduty axles on 44 x 19.5. When we did the axle swap he also switched to full hydro steering with a 2x8 inch single ended ram. It has never been able to turn left, which is the weak direction on his ram. last we checked the ram was getting 1400 to 1500 psi to either side when it was trying to turn. The pump and all the hydraulic components are new. We did the upper ball joints this last weekend, and it will turn some when its cold or in reverse now. We have a 2.5" ram we're going to try tonight, other than that the only other thing we can think of it replacing the lower ball joints. Is there anything else we should be checking?

 

[JohnnyJ]

With the ram disconnected and tires off the ground, can the steering be freely cycled by hand?

What backspacing on the wheels? Is there a lot of scrub?

 

[Frodo]

I'm not sure about the first, I'll check tonight. There might be 2 inches of back spacing. There is a ton of scrub.

 

[JohnnyJ]

Unless you feel something wrong cycling with the ram disconnected, or if there's obviously mechanical issue like sloppy joints; then I don't see that throwing consumable parts is going to solve the issue.

Good chance if you had a "good" steering valve for 2x8 ram, it'll be slow for the 2.5x8 and painfully slow for 3". Billavista moved all his calcs to his own site, he has one for hydro steering.

BillaVista.com-Hydraulic Steering Calculator Tech Article by BillaVista

 

[Bebop]

2" is fucking tiny

 

[JohnnyJ]

2" is fucking tiny

Especially for 20" wide tires with massive scrub radius. #prayfortheballjoints

 

[Frodo]

2" is fucking tiny

Especially for 20" wide tires with massive scrub radius. #prayfortheballjoints

Its closer to 4 inches, but yes still tiny. He bought the wheels and tires used and that's what they were.

It turned easily in the air without the ram attached.

They threw the 2.5" ram on before I got there last night. It turns fine in 2wd now, but not in 4wd. they rotated the ram so it extended the other direction and that didn't do anything.
I did pass on the link to Bill Vista's site.

 

[RadialDynamics]

Do you know the rod diameter of that 2x8 single ended ram? If he is struggling to turn it in the direction of the ram retracting then yes, it sounds like the ram is undersized. If you can confirm the rod diameter, I can run through the calcs for you

edit: just read further and saw that reversing the ram direction did not fix it. Can you grab a picture of the axle/ram setup?

 

[Frodo]

Do you know the rod diameter of that 2x8 single ended ram? If he is struggling to turn it in the direction of the ram retracting then yes, it sounds like the ram is undersized. If you can confirm the rod diameter, I can run through the calcs for you

edit: just read further and saw that reversing the ram direction did not fix it. Can you grab a picture of the axle/ram setup?

I can. It will be a few days though.

 

[Frodo]

Do you know the rod diameter of that 2x8 single ended ram? If he is struggling to turn it in the direction of the ram retracting then yes, it sounds like the ram is undersized. If you can confirm the rod diameter, I can run through the calcs for you

edit: just read further and saw that reversing the ram direction did not fix it. Can you grab a picture of the axle/ram setup?

We thought about it later, and without moving mounts reversing the ram wouldn't help. We are trying to get it running for tomorrow, so he just slapped a 4x8 ram on it and now it turns left. The steering wheel is 9 revolutions lock to lock, so its a good thing we don't go fast.