Rockshaft not working on 4100

10678 Views 10 Replies 2 Participants Last post by Kennyd, Feb 29, 2012

Sasquatch

Discussion Starter · Feb 19, 2012

Ok, this is on a 4100HST 4x4 with FEL all factory.

Alright, so while hooking up my aux hydraulic spool I needed to raise the three point to put in the new hydro top link. The hydros were all disconnected and so I placed the lever in the highest position and then placed a jack underneath the attachment I had on it so I could move it the inch I needed to get the pin out. Well. I got it all back together and tried to lift it. Nada. Hydros aren't dead headed and all the other functions work well ie (steering and fel)

So here's what I did to troubleshoot.

1. Checked for dead heading as sometimes happens if the aux's aren't plumbed correctly. No issue, the tractor's not bogged down and other functions ok.

2. Checked that the lowering speed adjuster was in the open position and the lever for height adjustment lever moves through the range. A little sticky, but it works ok.

3. I reinstalled the oem pb kit to see if it was a flow issue. No change.

4. I went ahead and removed the rockshaft assembly and inspected for mechanical damage. None seen. checked the linkages, etc and hadn't noticed any physical damage etc. When reassembling I noticed the control valve for the rockshafts relief valve was jambed in the plate it rests in. The plate was slightly ascew so I loosened the three screws that hold it in and it was still off so I smoother out the hole a little so it would rest in it like shown in the manual. Reassembled and no change.

5. Removed control valve again and completely disassembled it figuring it may have some debris in it since it's supposed to be the last in line to receive fluid and it may have gotten something in it since I installed many new components. Didn't see anything and it appears all the valves in the control move like they're supposed to.

6. While the control valve is out of the rock shaft assembly I blew through the return line on the aux hydros and did see flow from the return port inside the rock shaft housing for what it's worth.

I did notice that if you use the fel to the point it starts to bypass and then let off really quick it'll make the rock shaft move up about an inch. It does this consistently. It will lower correctly when ordered to.

I'm beginning to wonder if I didn't tweak the eccentric shaft(or inside levers) that the control lever is mounted to causing the control lever to not engage the control valve spool enough to raise the rock shaft.

I guess I should have checked the engagement of the actuating mechanism with the control valve installed in the rock shaft when I had it out.

Anyone encounter something like this?

See less See more

Save

1 - 11 of 11 Posts

Kennyd

· #2 · Feb 20, 2012

Wow, quite a story SQ...lets try to break this down into small pieces to get this figured out.

Alright, so while hooking up my aux hydraulic spool I needed to raise the three point to put in the new hydro top link. The hydros were all disconnected and so I placed the lever in the highest position and then placed a jack underneath the attachment I had on it so I could move it the inch I needed to get the pin out. Well. I got it all back together and tried to lift it. Nada. Hydros aren't dead headed and all the other functions work well ie (steering and fel)

What valve did you use? With or without PB plug?

3. I reinstalled the oem pb kit to see if it was a flow issue. No change.

Was this PB kit already installed on your tractor, or did you add this as part of the spool install project? If you just added this, then I know what the problem is...

Answer these then we will continue please. And I moved this to the Hydraulics forum, seems to fit better there.

See less See more

Save

Sasquatch

Discussion Starter · #3 · Feb 20, 2012

Kennyd said:
Wow, quite a story SQ...lets try to break this down into small pieces to get this figured out.

What valve did you use? With or without PB plug?

Was this PB kit already installed on your tractor, or did you add this as part of the spool install project? If you just added this, then I know what the problem is...

Answer these then we will continue please. And I moved this to the Hydraulics forum, seems to fit better there.

The PB kit is a oem job and functioned well before I started installing this: http://www.surpluscenter.com/item.asp?item=9-7863&catname=hydraulic

What I did was splice the prince valve in after the OEM bracket that mounts out back I took the return line (or as JD calls it the IN port) after the bulk head fiting on that bracket and connected it to my IN on the prince and took the OUT from the valve and plumbed it back to the return on the section near the scv valves. Essentially splicing it in the return (or IN) line after the bulk head fitting where the OEM QDs are. I'll get a pic to clarify.

The set screw that re routes the fluid to the PB was installed when I installed the PB kit. I think that's what you were thinking:wink: Wonder if it came loose though? I know I torqued on it.

Hope that clarifies it. I know I have a problem explaining things.

See less See more

Save

Kennyd

· #4 · Feb 20, 2012

Diagram Text Design Parallel Technical drawing

Auto part Text Diagram Line Automotive engine part

Diagram Text Auto part Technical drawing Plan

Here are all the related pictures from JDP.

The set screw that re routes the fluid to the PB was installed when I installed the PB kit. I think that's what you were thinking:wink: Wonder if it came loose though? I know I torqued on it.

Yes, that is exactly what I was thinking-hoping really for you! I know it burned me when I installed my PB kit, and I have seen and helped many others who have done the same thing.

I am struggling to find any more suggestions:think: I am trying to relate how jacking up the implement would cause this problem and drawing a blank.:banghead:

I know this is stupid but are you sure one of the hoses is not binding the linkage? I know it's tight in there...

I did notice that if you use the fel to the point it starts to bypass and then let off really quick it'll make the rock shaft move up about an inch. It does this consistently. It will lower correctly when ordered to.

This has me confused as well, that is a symptom of a valve in parallel and not in series.

See less See more

Save

Sasquatch

Discussion Starter · #5 · Feb 20, 2012

Yeah, it's got me baffled. I thought maybe the prince was restricting the flow/pressure to the rockshaft since I heard it's last to receive flow in the system. So I removed the valve and hoses I installed and replaced it with the original hose for the PB return line hoping it was a flow restriction and it didn't help.

One thing I noticed when it the control valve was removed is that there's three holes for the valve in that bore on the Rockshaft housing. The first one is the one that goes to the rock shaft hydro cylinder, the next I assume is the IN for the rock shaft control valve (the return flow from the other valves) When I disconnected the return line from the PB QD and blew threw it and it came out of that hole. There's another that's definitely a return since it's not connected in that bore and can't be connected to (looks like it dumps directly into the housing and back into the trans since it doesn't have a tank). Thinking about it I bet that's the port for the relief valve. While everything was control valve was out I lowered the FEL and noticed fluid coming out of the third hole. I would think that if the relief valve was ok no fluid would come out of this hole unless it was in bypass to relieve pressure. I would think that the normal return would come out of the second hole to supply pressure/oil to the components later in the system. Think I need to study up on the schematics.

See less See more

Save

Sasquatch

Discussion Starter · #6 · Feb 20, 2012 (Edited)

Ok, I studied the diagram and I am correct about the series of holes. The third hole is a pressure dump hole to relieve system over pressure. I don't think it should be dumping fluid unless it's relieving pressure. I think that's my problem. I think the rock shaft jumps because the slight bit of a pressure bump overrides the pressure relief valve and gives it to the rock shaft for a brief moment. I'm going to take a look at it as soon as possible. In a few days since I have a weird schedule at the moment.

Edit: After further looking the fluid I saw was normal. Still not discounting that the relief pressure might be bad, but I'll inspect it. I probably need to get a pressure gauge in their somewhere to test the psi of the nominal pressure. But there isn't a number given for it.

See less See more

Save

Kennyd

· #7 · Feb 20, 2012

Sounds like you have a good handle on it SQ, let me know if I can help in any way...

Save

Sasquatch

Discussion Starter · #8 · Feb 23, 2012

Well, I removed the relief valve and I didn't see anything wrong. This weekend I'll start it with the control valve removed to see if it's getting good flow through the port that's supposed to supply it with pressure. I'll also pick up a pressure gauge to test the relief valve to see if it's actually working well. It'd have been nice to A. Have a pressure test port for the rock shaft side of the system as well as a schematic that shows the system with the scv valve installed.

See less See more

Save

Sasquatch

Discussion Starter · #9 · Feb 24, 2012

Well, I've been playing with some HID lights the wife bought me for being good and not using our tax money to put a down payment on my dream bike, but... I did mess with the green thing a bit.

Bought a pressure gauge and some fittings from the hydro store to check the relief valve and nominal flow pressure readings. Not sure what the nominal flow pressure is. It've been nice for them to publish that.. Maybe I'm not looking in the right area...

I did start it up sans the control valve for the rock shaft and it flowed quite nicely out of the supply port for it. That being said flow doesn't = pressure.

I'll reassemble the control valve and install it this weekend and re test it. Never know, maybe I inadvertently fixed it. Hope so. Although I don't like phantom fixes.

See less See more

Save

Sasquatch

Discussion Starter · #10 · Feb 29, 2012

It's fixed!

So after reviewing everything I did pre and post mortem I've come the conclusion of my investigation.

I believe that the balancing valve was stuck in the rock shaft control valve. I'd taken the back end apart a few times and didn't see anything wrong. The last time around I took the front end of it apart. In the front there's something called a "cartridge" this cartridge is aka the balancing valve. I didn't notice anything suspicious when I dissected it, but upon reassembly I noticed the actual spool valve that is actuated by the rock shaft draft linkage was quite a bit stiffer than before. I did check to make sure that spool moved before installing the balancing valve. So, I put it back together and installed it into the housing and tested. Viola! Works correctly! So that issues corrected. Now I just have to put all the other stuff back together. That'll happen this weekend when it's a bit warmer.

Thanks for all your help!

See less See more

Save

Kennyd

· #11 · Feb 29, 2012

Wow, what a story! Your persistance certainly paid off!

Save

Reactions: 1

1 - 11 of 11 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month