Go BottomJohn Deere BH 46
 | wingwiper
Join Date: Jun 2004 Posts: 676 
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2006-05-01 128640
As we were writting about and discussing last fall, my BH 46, back boom will drop 1 inch per minute with the engine running. I was told to run it with the travel pin in, because I had complained that by the time I could drive to the other side of the hole, the boom would tilt and cause the bucket to drag.
They cam out in November and replaced an SCV Valve, claiming that John Deere had gone to a different Manufacturer about 5 years ago.
This weekend was the first chance I have had to hook up and use the BH 46 since the repair. IT MADE ABSOLUTELY ZERO DIFFERENCE, it still drops just as fast as it did before.I didn't even get the hydralics up to a Hot temp and it was dropping. I just got off the phone with the dealer, no other ideas for solving this annoying problem. Keep in mind, this is under NO Load and with the engine running.
Oh Yeah Hey Dr, have you had a problem with that Grease fitting mounted on the very bottom of the boom I am referring to, shearing off? I have, everytime a rock rolls down and hits the back of the BH, it usually will shear off that grease fitting, I replaced it twice yesterday. I refer to the base of the boom where the two cylinders that make it go left or right, under that pivot, on the bottom side is suppose to be a Grease fitting, if you are like me, it probably looks like a Dipple.
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Add PhotoJohn Deere BH 46
 | DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada 
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2006-05-01 128642
I had better go out and look after breakfast.
The basic cause for the droop has to be the scv valve. I have often wondered if they could be matched with another brand or rebuilt to tighter tolerances at a good hydraulics shop.
If I asked this before pardon my memory flux.... What sort of hydraulic oil are you using? ....
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| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-01 128643
I had it serviced (50hr was actually 80 hr) in August and they put in the JD stuff, Purple, Yellow label on a white jug. I still have some in the container out in the yard.
They replaced the SCV Valve after I told them I had two friends who bought the Orange and they do NOT have a problem, at all.
DR the grease fitting is a 1/4" short and it won't come out with an extractor bit, I just drilled it and screwed the new one right in, twice. ....
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| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-01 128644
I had it serviced (50hr was actually 80 hr) in August and they put in the JD stuff, Purple, Yellow label on a white jug. I still have some in the container out in the yard.
They replaced the SCV Valve after I told them I had two friends who bought the Orange and they do NOT have a problem, at all.
DR the grease fitting is a 1/4" short and it won't come out with an extractor bit, I just drilled it and screwed the new one right in, twice. ....
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Add PhotoJohn Deere BH 46
 | JasonR
Join Date: Jan 2006 Posts: 142 Northern Indiana 
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2006-05-01 128646
ww, sorry to hear about your issues...
My 46BH will drop maybe an inch per hour with the engine off. I have not noticed any dropping with the engine on.
No issues with the grease fitting either, but then again I don't do much work with rocks. You may need to bolt/weld on a small guard or something.
Jason ....
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Add PhotoJohn Deere BH 46
| DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada
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2006-05-01 128647
First: I think I am looking at the same grease fitting and it points UP on mine and is protected .... no chance that a rock could hit it.
Second: Read the label on that oil. If it says Low-Vis it is a big part of the problem. ....
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Add PhotoJohn Deere BH 46
 | Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
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2006-05-01 128655
Based on past experience a hydraulic cylinder that self-lowers is usually caused by internal cylinder seals and NOT the seals in the SCV's themselves.
This is not say it cannot be a defective or otherwise compromised SCV seal.
Basically if you think of a hydraulic system under pressure like a chain, the weakest link will always let go first. In a hydraulic circuit that is almost always the cylinder seals.
This is because they are NOT protected from shock loads by the relief valve when in system is in the "hands off" position, and why they give you a 'travel pin' in the first place, to mechanically protect the boom seals (the most vulnerable) from shock loads in this 'hands off' situation. Doing things like driving while carrying large rocks or stumps or logs with the BH can destroy a seal in seconds.
Once a seal has been compromised it is garbage and must be replaced. It's not tough to do, nor even expensive, but it does mean the cylinder must be removed from the machine to do it. Luckily in the case of the boom cylinder this is remarkably easy.
This kind of seal failure is easy to diagnose in a BH, but is sneaky since it mimicks a SCV failure or leak because there is no oil visible, all the oil leaking past the seal stays on the inside.
BTW, the same is true of a FEL or 3PTH lift cylinder, exceeding load capacity can cause a seal to be FUBAR in seconds, and cause a major PITA.
Best of luck. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-01 128659
DR
Points up?? How can it point up? are you sure you are looking at the same fitting? There is one that you grease that points up, on top for the left to right movement, but look at the base of the boom that is closest to the tractor and you will see the bottom most pivot, where the back boom pivots up and down from. There is No fitting on the inside top, only the hose going to the cylinder, on the very bottom of that pivot, is where the fitting was put. Not only will a small rock rolling down get it as it did yesterday but if you scarpe the bottom of the BH over dirt or whatever it will also shear it off.
I believe it is Low-visc and was told to use it in Summer months, the dealer was the last to put the hydralic oil in, I will be putting new oil in, in about 15 hrs.
Murf
Supposedly the dealer checked the cylinder at the 50 hr service and again when they brought it back in November to replace the SCV Valve, they said it is NOT the seal. It has been doing it from Day one. It is very annoying and a hassle to always have to keep jumping off and inserting the travel pin.
I have worked many a Hydralic Appratus and have NEVER had a unit drop so badly, WITH THE ENGINE running as I do with this BH. Damn thing works like crazy but drops like crazy too. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-01 128660
I also doubt I am going beyond Load Capicity, because if it can lift it, I am OK. If it can't lift it, then I would say I am beyond load capicity. I think it is more SNAFU
I have no problems with any other section of the BH, 3 ph or FEL, just that one boom. ....
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Add PhotoJohn Deere BH 46
| Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
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2006-05-01 128664
WW, that's why I said it's a sneaky one to diagnose.
Lifting is one thing, if the cyclinder seal is gone, as long as you're pouring in more fluid than can leak out, it will lift normally.
The problem only shows when you let go of the SCV, then the fluid that is leaking out is not being replaced, and down she goes.
The motor running has no bearing, on either the SCV seal, or cylinder seals, since the SCV, in a 'hands off' situtation, has no fluid going in or out to or from the BH, or whatever else is downstream of the SCV.
The test is simple, if you have quick disconnects, it's really simple. With QD fittings, put the BH boom all the way up, and QUICKLY unplug the fittings. If the boom still settles down, it's the cylinder seals, if it stays up the cylinder is OK. If you don't have QD's, you have to put a 1/4 turn ball valve (of suitable pressure rating of course) between the BH, and the SCV on both boom cylinder lines. Same drill, put the boom all the way & quickly close both valves fully.
Best of luck. ....
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Add PhotoJohn Deere BH 46
| Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
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2006-05-01 128665
Forgot to say, SHOCK load can easily bump a 50% load to many, many times the ratings.
If you want an easy (and dramatic) experiment sometime, put a hydraulic pressure guage between the line on the lift side of your FEL lift cylinder, and the SCV, riught at the valve where you can see it.
Put a moderate load in the bucket, and go for a little drive, you will be amazed to see how far up that needle jumps on even a relative small ripple in the driveway. A curb will usually peg the needle for a moment.
BTW, a simple $20 guage also makes a dandy weigh scale for guess-ta-mating stuff using the FEL. Put a 500 pound, 750 pound, etc., object in the bucket and just mark where the guage ends up in a 'hands free' state parked.
Best of luck. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-01 128667
Murf
Understand SHOCK and I am sure there may be a difference between CONTINOUS LOAD and SURGE LOADS. I would hope that JD had calculated this in to the design and has allowed a Govenor per se to ensure that the Lift rating will be far below the Spike rating. If their design has NO margin of allowance, WOW! I am surprised.
I refer to Speakers where they may be rated for 100 watts RMS and that means 100 watts contiuous and will handle in excess of 200 watts for brief periods with no damge. i would like to think the Engineers who design the Hydralic systems take in account that if they advertise a tractor to be able to lift 888 pounds, it means it will lift and transport it. Hell! what good will it do me if all I can do is lift it and then have to put it back down???? Of course I am going to have to move it and I doubt everyone lives on a paved parking lot type of enviroment.
I will tend to agree with your theory of the Seal, I do not know the tests that they ran for the cylinder and do hope their competence is good enough to be able to effectively test a cylinder, they sell some mighty BIG stuff there. I may just take DR's advice and replace the Low Vicosity with High and see what happens. I will probably have to change it for Winter.
DR
did you find where I was referring to for that Grease fitting yet? You bought yours before I bought mine, cuz I followed YOUR advice, SO I am sure mine on the Bottom is NOT an UPGRADE. LOL
....
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Add PhotoJohn Deere BH 46
| Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
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2006-05-01 128673
WW, I agree, JD "should have" engineered it to be able to easily withstand 'everyday' type stuff.
However, my experience (with most manuf., not just JD by any means) is that when they do something like including a 'travel pin' it tells me that the safety margin is not exactly generous if you get my drift.
DRankin has an excellent point about the viscosity, it may be all that is necesary to prevent the oil bleeding past the cyl. seals.
At least as I stated before, if it is the cyl. seals they are VERY easy to change. There are probably also stronger 'upgrade' seals available for your cylinder, if you had it apart it would be worth the few (literally) dollars to put the beefier seals back in.
Your comment about the dealer having 'big stuff' leads to think even more strongly that it's a cyl. seal. If their experience is with large const. equip. then the chances they have ever come across an overloaded cylinder are slim to none. Large stuff is over built like Mil. Spec. stuff is, they wouldn't be thinking cyl. seals. It's the small stuff that gobbles up seals.
Best of luck. ....
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Add PhotoJohn Deere BH 46
| DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada
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2006-05-01 128678
I thought you were describing the lower swing pivot, and I get now that you are referencing the lower boom pivot.
Mine is fine. Never been replaced.
As to the oil..... I would change to regular Hy-Gard, then cycle the FEL, BH and what ever else you have, and then drain and refill with regular Hy-Gard again.
The goal would be to dilute as much of the Low-Vis in the system as possible. The sump holds 3.9 gallons. My log splitter holds about a gallon by itself. I would guess that between the splitter, back hoe, FEL and top/tilt there is nearly double the sump volume.
If you consult your owners manual you will find that regular Hy-Gard has an operating range of 0 degrees F to +122F. The Deere web site specs say that the pour point is -40 degree F. I keep it in mine the year around.
You will also see in the Owners Manual that Low-Vis has an operating range of -40F to +80F. I don't know how it is where you are but it gets a LOT hotter here than 80 degrees in the summer.
You can warm up Regular Hy-Gard on cold days prior to use, but you can't do anything to keep Low-Vis cool when it is over 80F in the summer.
BTW, you won't find any information about Low-Vis on the Deere parts web site. It just isn't there, but the is a lot of info on Regular Hy-Gard. They just don't push it.
There is a big difference in the rate of droop with a thicker oil. It does not disappear completely, but it is much more manageable.
....
Link:
Click Here
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-01 128681
DR
Is that 80 degrees for Hydralic Oil temp or for the weather? My operating temp on the BH when the dealer tested it after 1/2 hr of average use was 135 degrees. So wouldn't that in itself decide I have the wrong stuff and why do they even make the low-vis and even the reg. if the max for either is 122 degrees? I think I just confused myself.
I was greasing my BH Sunday and I noticed that sometime last fall I must have sheared the fitting, I repaced it and I was digging and had to pile between me and the hole, had a wall on both sides and a rock about the size of a football rolled down the dirt pile and smacked the underside of the BH and I said "I wonder" yup! it sure did, that fitting lasted about 3 hrs. Glad I bought a pkg. ....
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Add PhotoJohn Deere BH 46
| DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada
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2006-05-01 128683
All the references are to the air temperature in which you operate the tractor.
In the winter my FEL will stay up almost all day. In the summer heat it stays up about 45 minutes.
As I continued to dilute the factory fill of Low-Vis I suspect those times will improve. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-01 128693
DR
Can I ask a STUPID question?
What is the difference whether the air warms the oil to 135 degrees or working it warms it to 135 degrees, isn't the NET result the same?
....
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Add PhotoJohn Deere BH 46
| DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada
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2006-05-01 128694
I am not sure where the 135 degrees comes from, but the transmission oil in my tractor is a lot hotter on a 100 degree summer day doing dirt work than it is on a +25 degree winter day plowing snow.
I can put my hand on the Tn'T SCV and feel the temperature of the oil flowing through the open center valve body. It will raise a blister in the summer. It's just toasty warm in the winter.
I would imagine the effect of the fan forced oil cooler is factored in just like it would be with the engine cooling system. There has to be an air temperature at which the radiator will no longer cool the engine sufficiently to keep the coolant from boiling.
The Deere specs suggest that above 122 degrees air temp for Hy-Gard and 80 degrees for Low-Vis, the oil in a hard working tractor will retain enough heat after going through the oil cooler to either break the oil down or render its viscosity so low as to cause performance problems.
Whichever it is, if it is that hot(122)outside you will find me under a nice shade tree with a cool drink, and not flogging the tractor. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-03 128769
Dr
The 135 degrees comes from when the Tech came to my house and after about 1/2 hr of Normal work put a temp gauge on my hydralic line (looked like an Amp meter) and measured 135 degrees and then measured the drop over a 3 minute period. It dropped 3 1/2 inches back at the pivot in 3 minutes and he said it was accpetable, I only laughed.
Figuring a person with a fever can get to 104 degrees another 31 degrees for a working hydralic system doesn't really seem to be that Hot. So if hydralic oil is good ONLY for 122 degrees what do you mean BOILING? that is 212 degrees for water. ....
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Add PhotoJohn Deere BH 46
 | kwschumm
Join Date: Feb 2003 Posts: 5764 NW Oregon
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2006-05-03 128774
The JD numbers DR was talking about were recommendations for ambient air temperature, not hydraulic temp. When the Tech says it's in spec that doesn't mean diddly unless the JD rep agrees with him. Escalate the problem to the service manager, then owner, then the JD rep as necessary. Be polite but inquisitive and firm. They will likely stop talking to you if you lose your temper. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-03 128775
KW
I did all that already and that is when they replaced the SCV Valve and that made no difference.
Ok! I now have a STUPID question for you ( I am trying to understand everything I think I don't understand)
If the specs refer to ambient air temp and the ambient air temp is 100 degrees how will that have any affect on a hydralic fluid that is running at 135 degrees. Yes! I know that is I was in -40 degrees that the fluifd probably would never heat up that much due to the real cold ambient air, but when it is only a few degrees different from the operating temp, what difference does it really make? Can 95 degree outside air keep the 135 degree hyrdralic oil from raching a Boiling point versus if the outside air was 105 degrees? would there be a 10 degree difference in the oil? or is there a ratio like a 10 to 3 or whatever? ....
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Add PhotoJohn Deere BH 46
| JasonR
Join Date: Jan 2006 Posts: 142 Northern Indiana
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2006-05-03 128781
ww
Does your BH drop at the same rate for all of the following conditions?
1. Engine running
2. Engine off
3. BH Quick Disconnects disconnected (as I beleive Murf recommended).
I only mention the engine running vs. off, in the rare case where your SCV is out of adjustment, and it's actually 'powering' the BH down (like gently leaning on the control handle). ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-03 128784
Jason
You bring up a excellent point but...... I had the DCV Valve replaced, could there be an adjustment at the lever that is putting the pressure on the Valve and not with the walve itself???
Engine running it drops fast, I haven't really checked with engine off, for I usually have the pin in.
I know Murf sugessted the disconnect routine, call me a coward but I really don't want to disconnect the main line with pressure and engine running. I was trying to think of way doing it by releasing the pressure first and haven't been able to come up with an idea, so I have ignored his suggestion for the time being. ....
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Add PhotoJohn Deere BH 46
| DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada
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2006-05-03 128791
I got to thinking it about it. Murf is on the right track. It has to be the cylinders.
I have to tie up the stabilizers while the backhoe is off the tractor or they will eventually droop all the way to the floor.
In any case, the problem is much, much, worse with Low-Vis and warm temps, which points to viscosity and seal issues. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-03 128792
DR
I think you are right and I forgot to check the 5 gal pail in my yard last eve. I like Jason's response as well and I wonder if there is a lever adjustment, like is my lever out of whack and keep the valve open just a tad? That makes sense and I know there are som eset screws on it and will have to mess with it a bit and see what happens. WOuld be great to be that simple. ....
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 | ncrunch32
Join Date: Dec 2003 Posts: 762 Kingston, NY 
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2006-05-03 128796
On my 47 I have to have it pinned all the time when not in use. When the JD dealer delivered it to the house the head mechanic warned me to tie the stabilizers up. He had had customers who parked the tractor in the garage, stabilizers dropped in a few days and damaged the car in the next bay.
If I leave pins out while running the tractor I have to remember to go back and raise the boom back tight about every hour or so. I can imagine with Low-Vis it would be much worse. ....
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Add PhotoJohn Deere BH 46
| JasonR
Join Date: Jan 2006 Posts: 142 Northern Indiana
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2006-05-03 128797
ww
I don't think you need to disconnect the BH with the engine running. Once the engine is off - simple disconnect the BH and see what drop rate you have - this is to determine SCV vavle vs. Hydraulic cylinder seal issues.
Also, if it looks as if it's the SCV valve out of adjustment, what should be a simple test is to reverse the hoses going to the boom and see if it raises 1" per minute while running.
Jason ....
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Add PhotoJohn Deere BH 46
| Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
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2006-05-03 128802
WW, you brought up a slender point I missed mentioning, but Jason is right, you would of course disconnect with the engine OFF.
I don't believe you will find an adjustment, per se, since the detent is an integral feature of the valve, the control cable or rod if it is a remote valve could be out, but the detent doesn't change, just the lever position would.
As for the engine running / not running, again, I go back to my previous point, the detent that closes all the passages to the BH is internal and an integral part of the valve, there is no 'adjustment' in the valve that could cause that.
A bad O ring could, but that is why I said to seperate the BH from the valve, that one 5 minute test will tell you which side of the disconnect the problem lies on.
Bear in mind here, there is a real catch 22 when it comes to seals in cylinders and valves, if they are too tight they will make for hard operation and VERY premature wear, if they are too loose they will leak, as I believe is the case here. They are like piston rings, the balance is a very delicate one, a definite compromise.
This being the case, a leakdown from fluid bypassing the seals, the higher viscosity will definitely help the situation. As an example, my big backhoe runs 68 weight oil all year round!!
As for ambient temperatures.... The only dumb question is the unasked one, because you don't learn from it!!!
The oil cooler, etc., can only create a temperature differential of "X" degrees, and the system needs to run below "Y" degrees, so for example, if the max. difference is say 80°, and the fluid temp. needs to stay below 160°.
If it is 32° outside, and the fluid can only get to 80° higher than that, 102°, then the system will be running well below it's design maximum temp. If however, DRankin is digging a hole and it's 120°, and the system can only keep the fluid 80° hotter than that, at 190°, then he has a 30° differential problem!!!
Make any sense or did I just confuse the daylights out of it now?
Best of luck. ....
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Add PhotoJohn Deere BH 46
| wingwiper
Join Date: Jun 2004 Posts: 676
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2006-05-03 128804
Ok!
I know I am going with a higher Visc.
I need to reverse the two hoses at the SCV to see if the opposite happens.
I need to disconnect the main feed of the Bh and see if it still drops, if it does it is the Seal and not the Valve.
The cooler will only keep thje oil x degrees cooler that the outside temp, the X is unknown and the hotter the day the higher to the 122 I will be getting. That makes sense.
I know that earlky this spring when it has been cool out, I have hosed the tractor down after some FEL use and got steam off of my lines by my seat.
O rings or seals are metal and not rubber, so the tolerance is more critical, do not want it to be to small for I will get uneccasry wear and shorter life of the cylinder sleeve. Too loose and I will be getting sloppy holding times.
Well I can see I have my day off already planned for checking out the BH.
Thanks everyone ....
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Add PhotoJohn Deere BH 46
| Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
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2006-05-03 128807
Ya gott'r right between the eyes!!!!
You may also want to look into other items to help keep temps. down even though you're changing to hish vis. hyd. oil.
Basically anything that will help keep the engine cooler will also help keep the hyd. fluid temps. down as well. Things like adding "water wetter" to the rad., making sure the fan shroud is as close a fit as possible, keeping rad. as clean as possible, etc., will go a long way to helping overall.
Best of luck. ....
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