[DougK20]

Can I flat-tow with full-hydro?? RESULTS!!!

The real question is, do I need to un-bolt the hydro ram from the tie-rod? Or, will leaving it attached damage the hydro system? I know linkage is not neccessary as it tracks & turns based on the castor angle of the axle. My only concern is damaging the hydro system. Nothing long-haul, just looking to get 30 miles to the local trails and back.

In case it makes any difference, I'm running an open-center, load reacting Danfoss steering unit w/ Howe aluminum TC pump

 

[[email protected]]

Assuming I'm seeing what I think I'm seeing, you've got a single-end cylinder on there; it won't correct track properly with the reactive valve, so I'd recommend against it. Whether it'll damage the hydro system, I'm not sure. It could.

 

[TONY K]

Seems to me that you'd push all the pressure out of the system kinda like if the motor is off and you keep turn the steering wheel. I don't know if that's bad or not??? I'd guess you'd be dry starting it when you fire it back up???

Basically I've been no help. Good question.

 

[Station]

As long as you do some short distance safe testing ( I also reccomend you try to do this on a lower traction surface like gravel just to be sure you will never have a tracking problem) to prove that you will be building enough centering force through your steering to make it track correctly , then you have nothing to worry about.

No you will not hurt the hydro system, and yes it will track properly.

With Danfoss valves there is absolutely no problem running single ended cylinders with load reaction , and it is even approved by Danfoss's top worldwide applications engineer for hydrostatic steering among other things.

I can not speak for other brand valves at this time as I use only Danfoss , and that is the extent of my knowledge/experience.

On a side note, I am sure Howe could have answered ..... oh wait .... never mind.

Sean

 

[hybrid-theory]

i use to flat tow with my truck with full hydro, was a major pain in the ass! most of the time the wheels would not turn in the corners, and would push the ass end of the truck sideways. it did work sometimes. i tried it with the tires at 25psi, then at ten, didn't make a difference for me.

 

[hybrid-theory]

oh yea i forgot to mention DO NOT disconnect the ram from the tierod, i tried that and the wheels went crazy, back and forth. would not recomend it. thought it it was going to pull me off the road.

 

[Tim84K10]

The man hath spoken.

 

[89TrailXJ]

oh yea i forgot to mention DO NOT disconnect the ram from the tierod, i tried that and the wheels went crazy, back and forth. would not recomend it. thought it it was going to pull me off the road.

Wonder if you had the ram disco'ed and a steering stabilizer in its place if it would still do that.

 

[jstarnes]

No you will not hurt the hydro system, and yes it will track properly.

With Danfoss valves there is absolutely no problem running single ended cylinders with load reaction , and it is even approved by Danfoss's top worldwide applications engineer for hydrostatic steering among other things.

You care to post up a Hydraulic schematic of these valves you speak of?

On a side note, I am sure Howe could have answered ..... oh wait .... never mind.

Sean

or are you just gonna talk smack blindly with nothing to back you up?

the reason I ask is because the schematics I have seen say you COULD have a problem, and it MIGHT not track correctly due to the small amount of fluid that would have nowhere to go when the cylinder retracts which would lock up the cylinder which COULD blow the seals depending on what pressure the cylinder was built to handle

Granted in my scenario all the dots would have to connect for this to happen BUT it could happen

 

[SHERPA]

I have no clue/input regarding towing with full hydro, but,, I wouldn't tow
much of anything with that tow bar.... maybe a VW bug........

I can tell those 1" tubes are about .120" thick.......... I'd be worried about those bars bending during turning at slow speeds, (lots of force) and bending
under severe braking..........

--Sherpa

 

[muddinmike]

what if you put a line conecting the two lines that run to each end of the cylender with a ball valve in it? So when you want to tow you open the ball valve and fluid is free to flow both ways while turning and not pass through the steering valve but when you want to drive it you shut the ball valve allowing the fluid to move the ram instead?

 

[stadlerm]

I disconnected my ram from the axle and tierod, and bungied it to the frame. I tried towing with it a little and doesn't work because as said above the tires won't turn around corners and won't reallign to track straight afterwards. You should be fine without the ram or steering stabalizer if you have proper castor. The mud terrains usually limit your speed more than anything.
mike

 

[DougK20]

Interesting responses. Now, what if I kept the ram attached to the tie-rod and left the truck running during tow? Would the circulation of fluid prevent system damage? Yet, still allow "return to center" based on axle castor angle? If it returns to center when I'm driving it, it should return to center when I'm towing it???

I realize this is all speculation. But, I will be hooking it up and testing it out this week. I'll let you know how it works!

 

[Station]

There is no difference if the truck is running or not. I will scan and post diagrams with an explanation of the circuit monday if time permits.

Sean

 

[Jason R]

why don't you disconnect the ram and replace it with a piece of tub w/ heim or some sort of joins on the end. That way the steering is locked. Or do you want the truck to be able to turn when flat towing mode? I dunno?

 

[DougK20]

Yes, I do want it to turn when turning.

Thank you Sean! I'm getting anxious to hook it and try it!

 

[cucvzuz]

hey doug what's the deal with the inverted bottom leaf spring??

 

[Trango]

I flat towed my buggy with my deuce a few times. It was totally fine, aside from being a total pain in the ass to air those big meats up and down. Full hydro, load reactive valve. It didn't try to push the ass end around at all... but my deuce DOES happen to weigh about 13.5k.

Dude I need to finish my trailer and put an end to my idiotic flat pull tomfoolery.

Bob

 

[jstarnes]

I flat towed my buggy with my deuce a few times. It was totally fine, aside from being a total pain in the ass to air those big meats up and down. Full hydro, load reactive valve. It didn't try to push the ass end around at all... but my deuce DOES happen to weigh about 13.5k.

Dude I need to finish my trailer and put an end to my idiotic flat pull tomfoolery.

Bob

single ended cylinder or duel ender?

the question is not will it work with a double ended cylinder because IF you have a reactive valve AND you have enough force to move the tires they will move

the question in my mind is how well will it work with a single ended cylinder I think it would work OK 50% of the time (flat towing) but what you have to ask your self is if I have a 32oz cup on one end and a 44oz cup on the other and you try and swap fluid between the two sides where will the extra 12oz's go

this is what you would be dealing with when you try to connect the 2 ports of a single ended cylinder with a hose and try to push/pull the cylinder rod

on a reactive valve the cylinder ports are tied together THROUGH the orbital valve's gerotor and valve SO the fluid has to move through the valve to tie left and right of the cylinder together

SO WHERE WILL THE EXTRA FLUID GO?

 

[Tim84K10]

Back into the reservoir probably.

I'd just borrow or steal a trailer.