reverser oil flow question

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psprague
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Re: reverser oil flow question

Post by psprague » Tue Apr 24, 2018 1:16 pm

One other thing, has the trans oil pickup screen (filter) ever been inspected? Perhaps it is collapsing under vacuum from the pump?
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dtoots1
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Re: reverser oil flow question

Post by dtoots1 » Tue Apr 24, 2018 2:12 pm

ok now....the original post mentions problem solving with "silicone", somewhere someone on this site...mentioned problems involving the silicone sealants and sensitive valves.....especially when squeeze out occurs....could this be the contaminate and being not cured complete actually coat part of the valving and loosen to create blockage in some manner??? yet cannot be blown out as cured to valve area......would assume would be hard to see to detect......sure seems to be contaminated as worked before silicone and gasketing.

oljoe
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Re: reverser oil flow question

Post by oljoe » Wed Apr 25, 2018 12:38 pm

psprague wrote:
Tue Apr 24, 2018 1:16 pm
One other thing, has the trans oil pickup screen (filter) ever been inspected? Perhaps it is collapsing under vacuum from the pump?
Psprague, the screen has been out at least 3 times. There was never any noticeable derbies, other than a few yellow paint flakes. It was removed and cleaned the first time when I was looking for the fluid leak and the HLR worked fine after that until I replaced the front cover gasket.
dtoots1 wrote:
Tue Apr 24, 2018 2:12 pm
ok now....the original post mentions problem solving with "silicone", somewhere someone on this site...mentioned problems involving the silicone sealants and sensitive valves.....especially when squeeze out occurs....could this be the contaminate and being not cured complete actually coat part of the valving and loosen to create blockage in some manner??? yet cannot be blown out as cured to valve area......would assume would be hard to see to detect......sure seems to be contaminated as worked before silicone and gasketing.
dtoots1, Thanks for the reply. Someone used the silicone to seal the front cover before I got the machine. Pressure blew out the silicone between the front cover and the transmission case causing a leak. The HLR worked fine until I replaced the silicone “gasket” with the home made gasket.

I see what you’re saying. That crap squeezes out everywhere when compressed. It is VERY possible that I missed a string of that stuff when trying to clean it off of the front cover and case.
With the minimal clearance on valves could it be causing one of them to stick open and venting pressure to the case?

I didn’t get a chance to check the pressures at the cooler last night. It’s raining today so it may be later on in the week before I can get back to it.
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Re: reverser oil flow question

Post by big_bgk » Wed Apr 25, 2018 7:00 pm

Hi Joe, I am ready for you to find the answer because it is the same answer that I think I need too. Thanks for doing all that work and posting it for the rest of us.. I'm totally confused inside this tranny, but I can rebuild a motherboard for my computer, Or as my son would say " I stated at a holiday Inn Express last night" cute.. Okay I am waiting and reading... Oh I can not for the life of me find my sel# on this JD450B, the plates where missing when I purchased it, but there is a plate on the engine with a sel# o67113T, so is that the machine sel# too? Thanks I'm no help for you on the tranny..Bill

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psprague
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Re: reverser oil flow question

Post by psprague » Wed Apr 25, 2018 7:27 pm

oljoe wrote:
Wed Apr 25, 2018 12:38 pm
psprague wrote:
Tue Apr 24, 2018 1:16 pm
One other thing, has the trans oil pickup screen (filter) ever been inspected? Perhaps it is collapsing under vacuum from the pump?
Psprague, the screen has been out at least 3 times. There was never any noticeable derbies, other than a few yellow paint flakes. It was removed and cleaned the first time when I was looking for the fluid leak and the HLR worked fine after that until I replaced the front cover gasket.
Going further out on a limb, could there be some foreign object in the bottom of the case that blocks the intake?

When I was fishing around elbow deep in the clutch sumps on mine, there where some interesting creatures living in the goo at the bottom. I've never done that to the trans but could there be a big enough flap of silicone to restrict the intake flow?
oljoe wrote:
Wed Apr 25, 2018 12:38 pm
dtoots1 wrote:
Tue Apr 24, 2018 2:12 pm
ok now....the original post mentions problem solving with "silicone", somewhere someone on this site...mentioned problems involving the silicone sealants and sensitive valves.....especially when squeeze out occurs....could this be the contaminate and being not cured complete actually coat part of the valving and loosen to create blockage in some manner??? yet cannot be blown out as cured to valve area......would assume would be hard to see to detect......sure seems to be contaminated as worked before silicone and gasketing.
dtoots1, Thanks for the reply. Someone used the silicone to seal the front cover before I got the machine. Pressure blew out the silicone between the front cover and the transmission case causing a leak. The HLR worked fine until I replaced the silicone “gasket” with the home made gasket.

I see what you’re saying. That crap squeezes out everywhere when compressed. It is VERY possible that I missed a string of that stuff when trying to clean it off of the front cover and case.
With the minimal clearance on valves could it be causing one of them to stick open and venting pressure to the case?

I didn’t get a chance to check the pressures at the cooler last night. It’s raining today so it may be later on in the week before I can get back to it.
I think flow and pressure at the cooler will be telling.
JD 450c forestry, JD 440A cable skidder

oljoe
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Re: reverser oil flow question

Post by oljoe » Fri Apr 27, 2018 12:06 pm

The pressure test at the cooler was telling, but I’m not sure what it’s telling. I have an idea where the problem might be but I’m not saying anything yet. I hope for some unbiased input from someone.

Inlet line pressure=60 psi.
Return line pressure=0 psi
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.

Here is a quote from the tech manual for testing the cooler bypass valve and the clutch lubricating bypass valve. “Pressure at the gauge on the cooler return line should be 58-72 psi. The differential between the gauges in the cooler inlet line and the cooler return line to be 80-100 psi. If deviation from these pressures is observed, check the valves and springs”

The cooler bypass valve is in the front cover and requires removal of the engine, clutch housing and the front cover. The clutch lube valve is under the transmission top cover in the case. I have had the cooler bypass valve out several times and the clutch lube valve out once. Both valves were clean and moved free in their bores.

Please share your opinions. Thanks, Joe
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psprague
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Re: reverser oil flow question

Post by psprague » Fri Apr 27, 2018 1:18 pm

That doesn't sound right. Cooler outlet pressure should be the lubricating pressure to clutches and output shaft and there seems to be either no pressure or resistance to flow. The manual says to control the pressure by the clutch lubricating bypass valve. If you open the cooler outlet fitting (since its 0 psi), do you get a trickle or a firehose? (ETA: I'd be real careful about doing this) Its suppose to pump 10 GPM so a big mess fast. (Amos, how is the clean up going?) Does the cooler get warm fast?

Cooler inlet pressure should be the 80 -100 psi (+outlet) differential set by the cooler bypass valve.
Pressure at the gauge on the cooler return line
(Fig. 16) should be 58-72 psi. The differential between
gauges in the cooler inlet line and the cooler
return line should be 80-100 psi. If deviation from
these pressures is observed, check the valves and
springs.
The initial transmission pressure seems suspect too. At the trans test point:
Run engine at 1800 rpm and record oil pressure.
Correct engaging oil pressure to H-L-R clutches is
170 to 180 psi with oil at 150-180° F.
When shifting from reverse to high or high to
reverse, the oil pressure at the by-pass valve in the
accumulator housing should drop from and return
to engaging oil pressure in 1.5 seconds average.
If deviation from this time is observed, readjust
clutch oil manifold needle valve. Always check
clutch adjustment before attempting to readjust
the needle valve.
When shifting from high to low or low to high,
the oil pressure at the by-pass valve in the accumulator
housing should be 170 to 180 psi in 1 second
maximum time after start of shift.
JD 450c forestry, JD 440A cable skidder

B Town
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Re: reverser oil flow question

Post by B Town » Fri Apr 27, 2018 5:24 pm

Plugged cooler?

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Re: reverser oil flow question

Post by B Town » Fri Apr 27, 2018 5:32 pm

I have heard and known of several large Cat power shift rebuilds that the owners tried to do "on the cheap". They didn't replace the cooler. And I every case, that I remember, the power shift failed prematurely. I have been told the cooler MUST ALWAYS BE REPLACED. I'm not sure I have ever heard this in our crawlers.

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Re: reverser oil flow question

Post by psprague » Fri Apr 27, 2018 6:28 pm

oljoe wrote:
Fri Apr 27, 2018 12:06 pm

Inlet line pressure=60 psi.
Return line pressure=0 psi
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.
Also curious is the pressure test port (barrel plug between feet) drops to 0 while cooler inlet pressure maintained 60 psi. Is oil circulating to the cooler but not into the whole control valve assembly (or at least a lot slower)? Is it shifting until the accumulator is exhausted?
JD 450c forestry, JD 440A cable skidder

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amos
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Re: reverser oil flow question

Post by amos » Sat Apr 28, 2018 6:20 am

psprague wrote:
Fri Apr 27, 2018 1:18 pm
That doesn't sound right. Cooler outlet pressure should be the lubricating pressure to clutches and output shaft and there seems to be either no pressure or resistance to flow. The manual says to control the pressure by the clutch lubricating bypass valve. If you open the cooler outlet fitting (since its 0 psi), do you get a trickle or a firehose? (ETA: I'd be real careful about doing this) Its suppose to pump 10 GPM so a big mess fast. (Amos, how is the clean up going?) Does the cooler get warm fast?

Cooler inlet pressure should be the 80 -100 psi (+outlet) differential set by the cooler bypass valve.
Pressure at the gauge on the cooler return line
(Fig. 16) should be 58-72 psi. The differential between
gauges in the cooler inlet line and the cooler
return line should be 80-100 psi. If deviation from
these pressures is observed, check the valves and
springs.
The initial transmission pressure seems suspect too. At the trans test point:
Run engine at 1800 rpm and record oil pressure.
Correct engaging oil pressure to H-L-R clutches is
170 to 180 psi with oil at 150-180° F.
When shifting from reverse to high or high to
reverse, the oil pressure at the by-pass valve in the
accumulator housing should drop from and return
to engaging oil pressure in 1.5 seconds average.
If deviation from this time is observed, readjust
clutch oil manifold needle valve. Always check
clutch adjustment before attempting to readjust
the needle valve.
When shifting from high to low or low to high,
the oil pressure at the by-pass valve in the accumulator
housing should be 170 to 180 psi in 1 second
maximum time after start of shift.
psprague,
Thanks for asking! Clean up is complete. Tests showed clean,all documents correct,etc. Took 11 yards of clean fill to fill the holes.But it gets better: Yesterday a friend/vendor of mine came to office and asked about the truck stuck on the railroad tracks on the north side of my property. Huh? Walked out with him and sure enough,there was a Ford 3/4 ton 4WD high centered across the tracks. Driver was walking around with a $100.00 dollar bill asking for anyone to get him off the tracks. On the other side of the tracks there is a concrete plant and they were just shaking there heads too. Anyway,called the police AGAIN and they arrived(3 cruisers this time) along with the railroad police,a fire truck,a Union Pacific work crew,a Missouri Pacific work crew and assorted R/R supervisors and reps from the oil field service company who employed the idiot driver who tried to cross the tracks.Train traffic stopped and eventually the truck was lifted from the tracks and we ALL looked for a fuel or fluid spill as truck had serious undercarriage damage. No spill though.
Now it gets interesting: my friend knew the Houston based VP of operations for the service company and sent him some pics. Another exec showed up about a half hour later and in the interume idiot was hooked up by the police then un-hooked. Turns out the idiot was suspected of having a meth issue. Did I mention he was(WAS) a supervisor for the oil field service company? $100,000.00 a year position.Fired on the spot by the last exec to arrive. Meth: is does a body BAD.
Can't get no worse right? Leaving work and a crack ho was lounging under the trees by the now clean spill site.Real nice there now. I stopped and pointed to the No Trespassing sign on the tree she was lounging by and told her nicely to move along. Then she proceeded to cuss me up one side and down the other.Back on the phone to police (then she decided to move along)and when I left they were looking for her for a "talk".
Went home and picked up my wife and we went to the farm to get away from the town craziness for a few hours.
Amos
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Re: reverser oil flow question

Post by oljoe » Sat Apr 28, 2018 8:44 am

I think that the clutch lube bypass valve may be the problem here.

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?

Another thing occurred to me this morning during my morning constitutional. 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. The only thing that bothers me about that theory is, the pressure drops to 0 at the pressure test port after a few shifts of the HLR. There would have to be an issue with the pressure regulating valve also.
B Town wrote:
Fri Apr 27, 2018 5:24 pm
Plugged cooler?
B Town wrote:
Fri Apr 27, 2018 5:32 pm
I have heard and known of several large Cat power shift rebuilds that the owners tried to do "on the cheap". They didn't replace the cooler. And I every case, that I remember, the power shift failed prematurely. I have been told the cooler MUST ALWAYS BE REPLACED. I'm not sure I have ever heard this in our crawlers.
Thanks for the replay B Town, I think the cooler should be replaced if there was a clutch or bearing failure. It would be possible for contaminates to be trapped in the cooler and dislodge at some point sending them through the valve system. This is a case of a “simple” transmission leak. I’m relatively sure “I” introduced some contaminate into the system by making the front cover gasket.
psprague wrote:
Fri Apr 27, 2018 6:28 pm
oljoe wrote:
Fri Apr 27, 2018 12:06 pm

Inlet line pressure=60 psi.
Return line pressure=0 psi
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.
Also curious is the pressure test port (barrel plug between feet) drops to 0 while cooler inlet pressure maintained 60 psi. Is oil circulating to the cooler but not into the whole control valve assembly (or at least a lot slower)? Is it shifting until the accumulator is exhausted?
The accumulator discharges with each shift of the HLR. The pressure check point is at the bypass valve in the accumulator valve system. It closes each time the pilot valve passes one of the venting orifices (neutral and high to low) and opens when the orifices are closed off.

I’m going to pull the top cover off today and see what I can find.
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dtoots1
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Re: reverser oil flow question

Post by dtoots1 » Sat Apr 28, 2018 8:47 am

Amos,
long tongue in cheek.......!!! Now what do you do for entertainment????

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psprague
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Re: reverser oil flow question

Post by psprague » Sat Apr 28, 2018 11:47 am

oljoe wrote:
Sat Apr 28, 2018 8:44 am
I think that the clutch lube bypass valve may be the problem here.

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?

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.

I'm curious if the pump output is enough. Chunks of silicone inside pump passages, out of place gasket blocking part of a passage?

There needs to be a smiley for WAG's. :D


oljoe wrote:
Sat Apr 28, 2018 8:44 am



Another thing occurred to me this morning during my morning constitutional. 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. The only thing that bothers me about that theory is, the pressure drops to 0 at the pressure test port after a few shifts of the HLR. There would have to be an issue with the pressure regulating valve also.

...

The accumulator discharges with each shift of the HLR. The pressure check point is at the bypass valve in the accumulator valve system. It closes each time the pilot valve passes one of the venting orifices (neutral and high to low) and opens when the orifices are closed off.

I’m going to pull the top cover off today and see what I can find.
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.

Paul
JD 450c forestry, JD 440A cable skidder

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Stan Disbrow
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Re: reverser oil flow question

Post by Stan Disbrow » Sat Apr 28, 2018 12:38 pm

Hi,

I usually stay out of 450 discussions. About all I know about a 450 is it ain't at all like a 440 even if it is only 10 larger and a 440 is a lot like a 430 for that particular 10. :P

But, oil coolers. Seen a lot of them. Many have inserts inside the tubing to force the oil to swirl as it passes. So, the flow rate winds up lower than it would appear from the tubing size. But, the heat transfer is much improved.

It occurs to me that if those swirlers were in the cooler and a piece of silly-con gasket were trying to pass thru, that could be a real issue.

So, just something I thought I oughta share. Back to reading the mail wishing I knew what was going on.....

Stan
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