reverser oil flow question

Post support questions about your JD350 and newer crawler here
oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Sat Apr 28, 2018 1:23 pm

Thanks Stan, I welcome any input. There are a lot of swirlers in my head right now.
psprague wrote:
Sat Apr 28, 2018 11:47 am
I'm curious if the pump output is enough. Chunks of silicone inside pump passages, out of place gasket blocking part of a passage?
A couple of years ago, trying to fix this problem, I bought a new pump front cover gasket and pump seals from John Deere. After spending more than $600 the problem was not resolved.
psprague wrote:
Sat Apr 28, 2018 11:47 am
The test port pressure starts out a normal 150+ psi and with each shift drop and returns to a lower pressure eventually ending up at 0?

Return times 1 second for H<->L and 1.5 seconds for R<->H shifts?

Sorry if I'm just not understanding you correctly.
The first 3 or 4 shifts of the HLR have normal lag times pressure dropping and returning in a couple of seconds. After that each shift takes more time for the pressure to return and eventually will not return and drops to 0.

I'm working on it now. Just taking a break. I'll share my findings later
Thanks All,
Joe
Straight 450 loader

User avatar
psprague
440 crawler
440 crawler
Posts: 105
Joined: Fri Apr 29, 2016 11:47 pm
Location: Olympic Peninsula

Re: reverser oil flow question

Post by psprague » Sat Apr 28, 2018 2:05 pm

re-reading thread. I see you tested flow already...

RIF :roll:
JD 450c forestry, JD 440A cable skidder

oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Sun Apr 29, 2018 7:19 am

psprague wrote:
Sat Apr 28, 2018 2:05 pm
re-reading thread. I see you tested flow already...
Paul, I didn’t check the flow at the cooler…..but I will. What will this tell us?


The first thing I did was take the pressure regulator valve out. There was no binding and the valve was clean. I Left the valve out, screwed the cap back on and started the engine. There was no pressure at any of the three gauges and the buzzing noise that I heard before was not there. When I put the valve back in and started the engine the buzzing noise returned and the pressures rose to where they were before removing the valve. The pressure point was bouncing from 90 to 160, inlet was 60 and the return was 0.

I removed the top cover and cranked the engine with the starter while watching the clutch lube “vent” where excess oil drains to the case. After 3 or 4 revolutions oil started to come out of the “vent”. I removed the cap that holds the valve and spring in place (think freeze plug) and removed the spring and clutch lube valve. No binding and the valve looked good. I checked the fit of both valves placing them in their respective bores and pressing down to make sure that they bottomed out in the bores, pulled them up a little and back down. I could hear a tap when they reached the seat.

I removed the steel lines that run from the case to the accumulator and clutch/bearing lube. Both lines were clean. I removed the valves from their bores and blew compressed air into the passage in the case where the clutch lube steel line was removed. Air came through the clutch lube valve bore, the clutch oil supply (accumulator) bore and through the “vent” to the case. I used my fingers and an old line to plug the holes and blew air again. The air was still coming out in the case somewhere below the gears and above the oil level. The cooler lines are still plugged with the gauges. Shouldn’t this passage be blocked with the cooler bypass valve since I’m putting pressure on the back side of the valve and forcing it to the seated direction?

With the cover off I checked the operation of the clutch circuit by applying compressed air to the oil supply inlet on the accumulator housing. I could see the accumulator spring compress and release as I shifted the HLR through the positions. The correct clutches applied at the correct shift positions.

Can anyone think of any other tests that I can do before removing the engine to get to the front transmission cover to check the oil cooler bypass valve and pump?
Straight 450 loader

oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Sun Apr 29, 2018 7:53 am

psprague wrote:
Sat Apr 28, 2018 11:47 am
The clutch lube valve should have little to do with flow through the cooler. If the valve is open with high flow, then the pressure would be near zero other than any residual backpressure. With no flow, it's position is not relevant.

With the cooler bypass valve stuck open, there still should be a normal 58 - 72 psi at the cooler outlet if the lube valve is working. But a wonky bypass valve might dump enough oil to cause a high-pressure drop to where the pump and the pressure regulator just can't keep up.
Just re-read this.....letting it sink in.
Straight 450 loader

User avatar
psprague
440 crawler
440 crawler
Posts: 105
Joined: Fri Apr 29, 2016 11:47 pm
Location: Olympic Peninsula

Re: reverser oil flow question

Post by psprague » Sun Apr 29, 2018 11:24 am

You said previously about flow and I forgot about it until I reread the thread:
When I had the metal supply lines off of the transmission case I turned the engine over with the starter to check the oil flow coming from the pump. It took a couple of revolutions of the engine to send oil out of the pressure port. When the oil started to come out it was a steady stream until I released the starter.
Can you explain this a bit more?
I removed the top cover and cranked the engine with the starter while watching the clutch lube “vent” where excess oil drains to the case. After 3 or 4 revolutions oil started to come out of the “vent”.
If this refers to the downstream vent of the clutch lube dump valve, is there 58 - 72 psi pushing the valve open, for oil be coming out of it?

I guess I keep coming back to why there is no back pressure in the clutch lube circuit. Is that valve somehow not working or is there an extra escape passage for the oil?



On my second cup of coffee this morning...



Paul
JD 450c forestry, JD 440A cable skidder

oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Mon Apr 30, 2018 8:52 am

psprague wrote:
Sun Apr 29, 2018 11:24 am
You said previously about flow and I forgot about it until I reread the thread:

When I had the metal supply lines off of the transmission case I turned the engine over with the starter to check the oil flow coming from the pump. It took a couple of revolutions of the engine to send oil out of the pressure port. When the oil started to come out it was a steady stream until I released the starter.

Can you explain this a bit more?
The metal supply lines that I'm referring to are the lines that run from the front of the transmission case to the accumulator housing and the clutch and output shaft lube. There are 2 lines and both screw into the front of the transmission case. One line supplies pressured oil through the valves to apply the clutches and one supplies oil, at a lower pressure, to lube the clutch and output shaft.

The lines were removed and I could view both holes in the transmission case. When the engine was spinning with the starter I could see oil flowing from the hole that would supply pressured oil to the clutches. I didn't notice any oil coming from the lube pressure hole. I need to check that when I get the regulating valve and clutch lube valve back in place. Shouldn't there be flow and pressure at both locations?
psprague wrote:
Sun Apr 29, 2018 11:24 am
I removed the top cover and cranked the engine with the starter while watching the clutch lube “vent” where excess oil drains to the case. After 3 or 4 revolutions oil started to come out of the “vent”.

If this refers to the downstream vent of the clutch lube dump valve, is there 58 - 72 psi pushing the valve open, for oil be coming out of it?
This IS the downstream vent for the clutch lube dump valve. Wouldn't I have to have 58 - 72 psi at the cooler return line before the clutch lube dump valve would open?
psprague wrote:
Sun Apr 29, 2018 11:24 am
I guess I keep coming back to why there is no back pressure in the clutch lube circuit. Is that valve somehow not working or is there an extra escape passage for the oil?
oljoe wrote:
Sun Apr 29, 2018 7:19 am
I removed the valves from their bores and blew compressed air into the passage in the case where the clutch lube steel line was removed. Air came through the clutch lube valve bore, the clutch oil supply (accumulator) bore and through the “vent” to the case. I used my fingers and an old line to plug the holes and blew air again. The air was still coming out in the case somewhere below the gears and above the oil level. The cooler lines are still plugged with the gauges. Shouldn’t this passage be blocked with the cooler bypass valve since I’m putting pressure on the back side of the valve and forcing it to the seated direction?
There may be an extra passage...but I'll have to narrow it down with a few more air tests.
Straight 450 loader

User avatar
psprague
440 crawler
440 crawler
Posts: 105
Joined: Fri Apr 29, 2016 11:47 pm
Location: Olympic Peninsula

Re: reverser oil flow question

Post by psprague » Mon Apr 30, 2018 11:34 am

Hi Joe,

A couple of ideas from re-reading everything again.

You made a pump gasket. Then I read you bought a JD one.

Is it possible to assemble any of the valves backward?
Pressure check point=90-160 psi to start and dropped to 0 psi after a few shifts of the HLR. When the pressure dropped to 0 at the check point the inlet line pressure remained at 60 psi and the outlet at 0.
Why is there pressure at the cooler inlet, yet none at the transmission test point? At speed, the pump is pushing out a gallon every 6 seconds, it gotta be going somewhere :)
If the clutch lube valve was stuck in the up (bypass) position or the spring was broken the oil would vent straight into the case and no pressure would be present at the cooler return line. The pressure would be 0 and there would minimal flow toward the cooler. Does this sound correct?
Yes. The cooler bypass valve is a compensating design though; it should produce about a 60 - 80 (58-72) psi differential. With the clutch lube circuit at 0 psi, the bypass valve appears to be operating correctly.
What if the cooler bypass valve was plugged on the inlet side? There would be no pressure on the return line or to the clutch lube circuit.
If the bypass is plugged, wouldn't that increase pressure on the cooler and the clutches?

You mention a buzzing noise. In the cacophony mine makes, I do not hear a buzz from the transmission. One of the valves vibrating? Broken spring? Pulsations from the pump? The cooler bypass and the pressure regulator would be the ones under high pressure.


Paul
JD 450c forestry, JD 440A cable skidder

oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Mon Apr 30, 2018 3:27 pm

Paul, Thanks for taking the time to have this discussion with me. It’s good to have someone to talk with that has knowledge about these reversers.
psprague wrote:
Mon Apr 30, 2018 11:34 am
You made a pump gasket. Then I read you bought a JD one.
Yes....When I discovered that the leak between the front transmission cover and the transmission case was caused by the silicone blow out I made a gasket for the front cover. That is when the symptoms that I am currently experiencing began. When I tore it down the second time to find out where it all went wrong I decided to go with OEM JD parts.
psprague wrote:
Mon Apr 30, 2018 11:34 am
Is it possible to assemble any of the valves backward?
Yes....some will swap ends but...I checked and double checked the tech manual each time I removed and replaced a valve. The manual shows pretty clearly the direction and location they need to be placed.
psprague wrote:
Mon Apr 30, 2018 11:34 am
Why is there pressure at the cooler inlet, yet none at the transmission test point? At speed, the pump is pushing out a gallon every 6 seconds, it gotta be going somewhere
“Oil is sucked from the transmission case reservoir by the clutch oil pump and constantly delivered to the pressure regulating valve. This valve divides the oil and sends it “on demand” to the H-L-R clutches for engagement or to the oil cooler to be cooled and filtered and returned for clutch lubrication.”

The pressures that I am experiencing make no sense according to this quote from the manual. If there is 60 psi at the cooler inlet there should be 60 psi at the test point and should be a close match at any pressure.
psprague wrote:
Mon Apr 30, 2018 11:34 am
If the bypass is plugged, wouldn't that increase pressure on the cooler and the clutches?
Yes..It should if everything is working.
psprague wrote:
Mon Apr 30, 2018 11:34 am
You mention a buzzing noise. In the cacophony mine makes, I do not hear a buzz from the transmission. One of the valves vibrating? Broken spring? Pulsations from the pump? The cooler bypass and the pressure regulator would be the ones under high pressure.
Mine did not make the buzzing noise when it was working properly. It started when I made and installed the gasket. Yes I do think it is one of the valves vibrating. The buzzing is tied in with the pressure at the test point. It dies off when a shift is made (pressure drop) and comes back when the clutches engage (pressure rise). When the pressure drops to nothing the buzzing will stop. I thought this was a missing oil cooler bypass spring because I found a spring, around the area I was working, a few days later. Then I lost it or couldn’t remember where I put it. I ordered a new spring when I ordered the new cover gasket. When I removed the front cover the spring was in its proper place and in good condition. The other two springs are out on the bench and seem to be in good shape.
Thanks,
Joe
Straight 450 loader

User avatar
psprague
440 crawler
440 crawler
Posts: 105
Joined: Fri Apr 29, 2016 11:47 pm
Location: Olympic Peninsula

Re: reverser oil flow question

Post by psprague » Mon Apr 30, 2018 5:13 pm

Hi Joe,

It's almost like 2 things going wrong.... :)

I think I'd try adding shims to the pressure regulator, to start. You are saying the transmission test port pressure is "90 -160" and the books says a more steady "170 -180".

There aren't too many other things that can be adjusted too.

Paul
JD 450c forestry, JD 440A cable skidder

oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Tue May 01, 2018 12:23 pm

psprague wrote:
Mon Apr 30, 2018 5:13 pm
It's almost like 2 things going wrong....
I agree there may be 2 problems happening in conjunction with each other.
psprague wrote:
Mon Apr 30, 2018 5:13 pm
I think I'd try adding shims to the pressure regulator, to start. You are saying the transmission test port pressure is "90 -160" and the books says a more steady "170 -180".
I have tried the shims add at the pressure regulator. I added 2 or 3 I can’t remember now. I think I ordered 6 from JD when I got the other parts.

My manual says 140 – 150 psi for the test port but I have a straight 450 manual and machine.
I will try some shims on the regulating valve and record the pressures. I may try a shim on the clutch lube valve to insure that it is fully closed and because it’s the only other valve where I have access.

Just a thought...what would happen if the rubber cooler return hose was blocked or was collapsed internally? That would create a 0 psi reading at the cooler check point but I’m not sure how it would affect the other pressures.

Joe
Straight 450 loader

User avatar
psprague
440 crawler
440 crawler
Posts: 105
Joined: Fri Apr 29, 2016 11:47 pm
Location: Olympic Peninsula

Re: reverser oil flow question

Post by psprague » Tue May 01, 2018 1:22 pm

Hi Joe,

That's interesting that you've added shims without seeing some effect, raising the pressure, decreasing pulsations, etc.

It should be a fairly direct relationship between the spring tension and the pressure at the test port. And downstream pressures too:
Initial oil pressure for the oil supply circuit is set by the pressure regulating valve, adjustable by shims. The other valves work in series to regulate oil pressure.
My book says this about the needle valve adjustment failing to have any effect. Talking about the clutch valve is interesting as it's one of the few places where high-pressure oil can vent.
NOTE: If neede valve has no effect on rate of shift, stop engine and turn clutch valve stop nut in until pedal moves away from stop. If unit responds to adjustments, clutch valve was not adjusted properly. If unit still does not respond to needle valve adjustment, remove transmission cover and check bypass valve, accumulator, and pilot orifices and screen for plugging.
Have you read this thread on HLR adjustments?

Some (more :) ) questions, just to fill in some of testing ideas.

Does it matter the time between shifts? Does the transmission lose pressure faster if you are making shifts faster? Does the machine just stop moving after a while even without shifting?

Does the high-pressure reading vary that much 90 - 160 all the time? Is the gauge needle bouncing and swinging a lot?

Does the cooler inlet test gauge show a steady 60 psi or does it vary and why (engine speed, shifting)?

Paul
JD 450c forestry, JD 440A cable skidder

User avatar
psprague
440 crawler
440 crawler
Posts: 105
Joined: Fri Apr 29, 2016 11:47 pm
Location: Olympic Peninsula

Re: reverser oil flow question

Post by psprague » Tue May 01, 2018 1:44 pm

oljoe wrote:
Tue May 01, 2018 12:23 pm

Just a thought...what would happen if the rubber cooler return hose was blocked or was collapsed internally? That would create a 0 psi reading at the cooler check point but I’m not sure how it would affect the other pressures.

Joe
Any blockage should decrease flow and increase resistance in the cooler. The cooler bypass valve would become active and the cooler should remain cold. A reduction of flow around the cooler and not being able to keep up with normal leakage of the clutch lube circuit?

Try a bypass at the cooler? Let it pump directly into the clutch lube circuit?

Paul
JD 450c forestry, JD 440A cable skidder

oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Wed May 02, 2018 1:25 pm

psprague wrote:
Tue May 01, 2018 1:22 pm
That's interesting that you've added shims without seeing some effect, raising the pressure, decreasing pulsations, etc.

It should be a fairly direct relationship between the spring tension and the pressure at the test port. And downstream pressures too:
I’m not sure if it had an effect on the pressure. The gauge needle was bouncing badly enough that I couldn’t get an accurate reading. I do know that adding the shims didn’t fix the problem that I’m having. I bought a new filled gauge and will try it to see if the needle is more stable.
psprague wrote:
Tue May 01, 2018 1:22 pm
My book says this about the needle valve adjustment failing to have any effect. Talking about the clutch valve is interesting as it's one of the few places where high-pressure oil can vent.

NOTE: If neede valve has no effect on rate of shift, stop engine and turn clutch valve stop nut in until pedal moves away from stop. If unit responds to adjustments, clutch valve was not adjusted properly. If unit still does not respond to needle valve adjustment, remove transmission cover and check bypass valve, accumulator, and pilot orifices and screen for plugging.

Have you read this thread on HLR adjustments?
With the top cover off of the transmission I can view the workings of the clutch valve. With the clutch pedal at rest on its stop the clutch valve is bottomed in the bore. When the pedal is depressed ½” to ¾” a lever makes contact with a roll pin at the top of the valve and causes it to raise. It seem to be set correctly. I have read the post before and reread it again to see if I missed something.
psprague wrote:
Tue May 01, 2018 1:22 pm
Does it matter the time between shifts? Does the transmission lose pressure faster if you are making shifts faster? Does the machine just stop moving after a while even without shifting?
Just after I replaced the silicone with the home made gasket I “drove” the loader about 300 yards and shifted to neutral. I got off to check for leaks and when I got back on it would not move in any gear. I shut it down and walked back to the shop to get a tractor and chain to pull it back to the shop. I can’t remember how long that took maybe 30 minutes. When I got back to the loader I started it, to raise the bucket, and decided to see if it would move before towing. I shifted the reverser into reverse, if memory serves me, and backed to the shop. When I stopped it would not go into high, low or reverse. I am relatively sure I used the clutch both times I stopped. After it sat for a while I was able to start it and pull onto the concrete slab. After that it has not left the yard. The travel distance has been 3’ to 75’ using the reverser. I DID use the clutch pedal last time I was testing. One thing that I noticed was the buzzing noise stopped and the pressure dropped as soon as I pressed the clutch. I let the clutch pedal back out and was pondering my situation when the buzzing VERY slowly returned but was more intermittent. The pressure rose and fell with the buzzing. When the buzzing and pressure became steadier the machine began to move again but seemed to be slipping in the HLR clutch pack. It pulled well enough I was able to get back to the concrete slab. During this test I didn’t completely disengage the clutch disc it was just the clutch valve. I'll have to see if it looses pressure without shifting. I can't remember if I've tested that.
oljoe wrote:
Tue May 01, 2018 12:23 pm
Does the high-pressure reading vary that much 90 - 160 all the time? Is the gauge needle bouncing and swinging a lot?
The gauge needle is bouncing rapidly from 90-160 and continues bouncing until it reaches 0. When it reaches 0 the buzzing also stops. The old gauge that I have been using is not an oil filled gauge. I bought a filled gauge for the main test point but haven’t used it yet.
psprague wrote:
Tue May 01, 2018 1:22 pm
Does the cooler inlet test gauge show a steady 60 psi or does it vary and why (engine speed, shifting)?
The cooler inlet gauge stays at 60 psi and doesn’t move even when the main pressure hits 0 and the RPMs change.

Joe
Straight 450 loader

B Town
1010 crawler
1010 crawler
Posts: 265
Joined: Fri Dec 11, 2015 7:04 pm
Location: Western Iowa

Re: reverser oil flow question

Post by B Town » Wed May 02, 2018 2:01 pm

Could the buzzing noise be pressure escaping through a faulty valve? Which one? Pressure builds up from the pump, so the pump is good, right? This normal pressure overpowers a faulty valve, causing valve to open and spill pressure down to zero. Buzzing noise is the vibrating valve. Faulty valve can't control pressure until engine is off ? I agree with previous posts that there is more than one common problem. If it were one common problem, your efforts would have found that problem by now. Wish I was able to physically be there, Bruce

oljoe
430 crawler
430 crawler
Posts: 81
Joined: Mon Feb 13, 2012 10:53 am
Location: Windsor, Missouri

Re: reverser oil flow question

Post by oljoe » Thu May 03, 2018 2:34 pm

B Town wrote:
Wed May 02, 2018 2:01 pm
Could the buzzing noise be pressure escaping through a faulty valve? Which one? Pressure builds up from the pump, so the pump is good, right?
I think the buzzing IS a valve. The only noise that I can say is similar is when a main hydraulic system has a low oil level. Isn’t it correct that it is air in the system that makes the valve vibrate because air will compress where the oil won’t? It seemed as though it was sucking air but I haven’t been able to find any place that air could be entering the system. Some of the air pressure tests that I have done for leaks have been inconclusive. I need to figure a way to test the valves for leakage and operation while they are in their bore.

We had rain and a couple of storms around last night so I didn’t get anything done. There are supposed to be more tonight. I’m ready to get back working on this thing instead of thinking about It.
B Town wrote:
Wed May 02, 2018 2:01 pm
Wish I was able to physically be there
Maybe I could load it on a trailer and head to western Iowa. :wink:
Straight 450 loader

Post Reply

Who is online

Users browsing this forum: No registered users and 6 guests