My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

[EE_Bota]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

Looking at the pictorial of the lowering speed control valve on my 2200 makes it look like there is a spring and check ball that keeps it from also being a raising speed valve.

I'm not sure this helps at all...but it could be possible to remove the ball and spring that does the check portion, and instead plug the port the ball blocks only one way so it is blocked both ways. This might deny it it's full speed up path, and force all oil through only the part controlled by the twist knob.

 

[Navigator7]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

I'm just having fun with this theory.

Hello Harvest Moon!

I'm not familiar with your piece of equipment....I didn't read all the posts....but am I to understand you are trying to smooth out your boom so it's perfect and not jerky?

Your post somewhere else drug me over here.
I know a bit about hydraulics and if your machine wasn't doing what you wanted in the first place...that's where you need to get back to.

Cun you speel out your problem for us publicall edukated yoots?
;-)

 

[Rockyridge]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

Hydraulic basics for dummies: My understand is that with power beyond valves the high pressure fluid passes through each valve in series until one of the valves redirects it, or a portion of it, to a cylinder to operate the cylinder. The rest of the fluid continues to downstream valves for use as necessary and finally back to the reservoir. The FEL valve can redirect a small portion of the fluid to move the cylinder very slow or all of the fluid to move the cylinder fast. Is the problem that the 3ph valve on these specific tractors does not allow for redirecting only a portion of the fluid as the FEL valve does? Is it all or nothing with that valve, but only on some tractors? Additionally, in the parts manual, the valve control look very similar to valve control for tractors that work smooth.

Another question comes to mind, is the valve is all or nothing, or is the feed back mechanism over reacting. Would it be a reasonable test to disconnect one end of the feedback rod (under the seat), , and slowly move the valve end until the 3ph went up to see if still jerked while controlling it that way. This would remove the hand lever linkage and verify that the feedback is not over reacting.

I would to do the test myself (and will if nobody has done it by the time it warms up a little) but I don稚 have a heated place to work on a tractor and we have minus 35 degree wind chill right now.

 

[slowzuki]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

The videos look exactly like on a large ag tractor when you adjust the 3 point hitch to have a fast raise response with a light implement.

It can be pretty violent on the implement and tractor.

I think it just adjusts the flow to the 3 pt hitch but I could be wrong.

 

[Navigator7]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

Another question comes to mind, is the valve is all or nothing, or is the feed back mechanism over reacting.

If the pump providing the flow of oil is a gear pump type, when you put a load on the flow of oil via a power beyond valve, that which is downstream can suffer a little or shut off all the oil.

If the pump is pressure compensated, like an excavator, all the valves will see the pressure and flow up to the limits of the pump.

 

[Harvest Moon]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

Hi Navigator7, if you didn't have a chance to read all 101 posts the first post #1, canoetrprs great ideas in post #65 & #72 and my experiment results in #81 will get you the gist of it. There are lots of ideas, suggestions and other input throughout. As for the pump, I'm just about positive it's not a pressure compensated pump.

Rockyridge, I've pretty much been convinced that there are two problems. A) the valve I have is lousy. The valve from the L3010 is much better and B) The flow to the hitch is too fast.

I haven't put much though into the feedback lever or the power beyond aspect. If or anyone wants to see if adjustments to the feedback linkage make a difference that would be great but I think the feedback linkage is overpowered by the bad valve and high flow.

I'm still holding on to hope changing the LSV out for the better one will help smooth out the performance with the L3010 PCV valve and the only problem left will be that the hitch is a bit on the fast side. I've pretty much asccpeted that we won't get L3010 performance because the L3010 probably has a larger cylinder but it would be nice to hear from someone with the specs. on that.

I have an order in for the L3010 PCV. $372.63. Should be in my hands next week. Oh how I love spending money.

 

[Reg]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

Reg, I'm thinking if we rule out the $5 parts with the 15 minute task then we can move on to more advanced solutions.

As far as factory set up, well, I think all L3400's with the lousy PCVs demonstrate similar malfunctions. Many thousands of them but I've only seen a few. The only solution I'm aware of to date is to replace the PCV with the one from the L3010.

There is definitely over shoot and quick stop. The quick stop first then the overshoot as the momentum throws the implement up past the stopping point. This is allowed by the one way/float nature of the 3 point.

I wonder if that can have a resonating effect on the linkage system or not.

Having not seen this...
I would take overshoot and the sudden stop as symptoms that it is not acting proportionally on the difference signal.
It is most likely going on at full speed until the sign of the difference signal changes.
Whether this is by (lack of) design or improper set-up - as I said, I havn't even seen one, not even just standing there switched off.

SOMEONE must have a shop manual for this and at some level of detail there has to be a set-up procedure for the rods, bell-cranks, whatever dingus thangs send the position signals back.
I'd want to do whatever set-up, calibration, alignment on all that FIRST.
My guess is that mis-adjustment there would/could/might cause some/most of the symptoms described, so I would want to get the set-up done to eliminate it, resolve the problem, or at least reduce the problem.

A reasonable theory might be that the set-up isn't being done at the factory and isn't part of pre-delivery check either.

 

[GMtb42]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

Progress report ?
Work , not work ?

 

[Harvest Moon]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

Progress report ?
Work , not work ?

I think what you are looking for is back in post #81. Still hopeful that the LSV change will affect a positive outcome. Still waiting on the L3010 PCV valve.

 

[Rockyridge]

Re: My quest for "Grand" 3 point performance from my "economy" tractor. The L3400

This weekend I was able to test the 3ph feed back and it was not any better raising the 3ph using feed back than the normal lever to move the 3ph, still jerked when moving up.

I did learn that the 3ph is not going all the way to the top though. I should be able to get an additional inch or so higher at the top arm by adjusting the feed back rod. This should be two or three inches at the end of the bottom 3ph links. Might be just what I need to keep the PHD from dragging.

There has been some discussion about the capacity of the pump in relation size of the 3ph cylinder. I know that there are many variable to calculate this but we may be able to learn something about their relative capacity by the observing the speed that the 3ph goes up.
For example with two systems with the same size pump capacity, the one with the smaller 3ph cylinder will go up faster and react quicker while the one with a larger cylinder will move slower but will have more power lift capacity.

After warm up plowing snow for about an hour, my L3400 (jerky 3ph) went from all of the way down to the top limit in just a little over 2 seconds running at 1000 RPM.

How about someone with a smooth 3ph timing how long it takes for their 3ph to move from all the way down to the top at 1000 rpm?

Thanks