450C Clutch Control Valve (HLR)

[DrLoch]

Has anyone played with the clutch control valve? Here is an issue that I have had with mine and maybe someone can shed some light. When I'm in 2nd speed gear and have High Range selected. If I stop by pressing in the clutch, when I release the clutch it takes some time before the clutch pack fully engages/locks up. If I'm up against a load in 1st or 2nd gear range, pushing dirt ect. if I push on the clutch to stop and then release it, it takes longer before full engagement. (When I refer to pushing on the clutch, I'm not fully pressing in the clutch like you would to change speed gears, 1 thru 4.) If I put the range selector in neutral and select forward Hi, Low or Reverse it seems to shift and lock in what I consider a normal time set by the needle valve. It's had this issue since I got it but now it's more noticeable now that I've been working in a valley area.

If I shift from forward to reverse without pressing the clutch, again it appears to be shifting and locking normally. As a test I've gone against a load pressed on the clutch to stop pushing and then released the clutch. If it was a heavy load and I selected high range it may not even try to push the load, but if I pulled back both steering handles I can feel the high range clutch fully engage and if I let go of both handles the loader will push the load. Hopefully I'm explaining it in manor someone else can understand what I'm saying.

If I'm in 1st speed gear it doesn't act the same which is understandable because of the gear multiplication. Generally speaking if I'm pulling stumps I will be using 1st speed gear since I may have to grab em and go forward and reverse to break the tap root. A lot of the trees I've cut down are gum trees and and sometimes the tap root is larger than the base of the tree on top of the ground. So as a generally rule I will go up and push against them blade, the 4:1 bucket opened up. If starts to push over I grab it with the bucket and continue to push and lift to get it out of the ground. If it doesn't move I go to the next stump, I'll come back for it later.

From what I'm seeing and understanding it appears the issue may be with the clutch control valve. In the manual I see that there is a screen but I don't see where the screen is in the circuit drawings to see if that may be causing what I'm seeing. BTW where is this valve?

[TexasJD]

Looks like there is a small screen in the accumulator valve. I don't see any kind of filter in the manifold and shift valve.

[DrLoch]

TexasJD, that is the filter I seen as well. Depending on where it's located in the circuit it could be causing the issue I'm seeing.

[TexasJD]

Looks like that screen is in the accumulator itself. According to the Tech manual the accumulator is in the range change compartment of the trans. Looks like the cover would need to come off to get it out.

[DrLoch]

I agree, looks like the cover will be coming off.

[DrLoch]

Go the issue resolved. I went through the clutch adjusment procedure and it made a huge difference. Now I believe I need to adjust the needle valve to slow the shift down. I generally always used the (hyd) clutch for my forward to reverse shifts anyways. Also, mine didn't have the filter screen in it. If you looked at the other post http://www.jdcrawlers.com/messageboard/ ... php?t=9347 I had a problem getting the accumulator pressure checking pipe plug out so I did have to take the top cover off.