Volvo 160BLC vibration during start and stop of swing

If a guy is willing to learn and ask questions, most folks will step up and help when and where they can. I try to stick with Volvos as its about all I know . It translates to quite a few other lines as well. If you pay attention to what you're reading and question what doesn't make sense, you'll pick up a lot. The fact that you've got your hands in it, the lessons are likely to stick. You always get more when you have skin in the game.

Good day Upta-maine
The question was a serious enquiry to you who come over as inquisitive mind - it is something our team has been considering. I would be interested if others who follow the HEF threads would be interested, the negative aspect is that we could not do it without costs. I must admit administering such a program to be more or less universal does seem a little daunting, see what the comment brings.
Kind regards
Uffex

Here's the rub, I and others are helping you troubleshoot a symptom. We're not there, we don't know your skill level, or for that matter, how much common sense you have. It puts us in the trick bag as, could we possibly get this guy hurt, while trying to help him out? I'm not saying you in particular, but any person who asks for help. There are certain things I'll feel someone out before I start sharing information. It's too easy to get hurt or killed. Some things you only get one chance to do it wrong. It could be the last. Ain't trying to scare anyone, just instill a healthy respect for things that could hurt them.

To clear up a few things on this thread.

• The last document uffex posted is incorrect in that the SH and PG ports on the brake valve are labeled opposite. The PG should be on the left and SH on the right. The way it is shown would allow the brakes to not release completely and a delayed release as you would be releasing with signal oil from the joystick and not pilot oil.
  
• The MU port is connected correctly in your pictures. MU is make up oil and is connected to the return circuit in the MCV. this oil goes through back pressure check valves on its way to the reservoir and is slightly higher pressure than tank pressure. This primarily used on circuits hat require make up oil or regeneration.
  
• Drain oil is case drain and any drain oil from any circuit than needs to drain back to tank without the added pressure from the back pressure check valves. This oil from the swing motor does go through the case drain filter.
  
• On uffex's last document where the cutaway shows the A and B port. As you look from left to right the passage first comes to the rebound dampening valves, in the middle are the 2 anti-cavitation valves and on the right are the 2 relief valves, The relief valves provide circuit protection and braking force when you stop swinging as has been stated. The check valves allow make up oil into the low pressure side of the circuit when needed and the rebound dampening valves allow for the upper structure to stop smoothly and not bounce back and forth.

I probably would have had you measure case drain pressure and also the swing relief valves before you removed the swing motor but that is too late now. I would also measure swing bearing play and inspect the swing gear grease bath to see what condition that is in.
If you can swing the upper stricture with the arm out and bucket off the ground the brake is not working correctly.

funwithfuel said:

Here's the rub, I and others are helping you troubleshoot a symptom. We're not there, we don't know your skill level, or for that matter, how much common sense you have. It puts us in the trick bag as, could we possibly get this guy hurt, while trying to help him out? I'm not saying you in particular, but any person who asks for help. There are certain things I'll feel someone out before I start sharing information. It's too easy to get hurt or killed. Some things you only get one chance to do it wrong. It could be the last. Ain't trying to scare anyone, just instill a healthy respect for things that could hurt them.

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FWF - I completely understand your point. You have a wide range of folks who come to you and ask for advice without you knowing anything about them. I am obviously the benefactor here. Screening folks before getting too far down the road is important and I'm sure everyone's situation is different. For me - I own a machine that is for my own use. I do not have it on jobs for customers and, because of that I do not have the ability (financial or otherwise) to drop the machine off in Volvo's yard and write them a blank check to fix it. I guess I should also say I really don't want Volvo fixing it behind closed doors because, in the end, I will be the one running the machine and I would like to have some idea what is really happening inside the machine. I want know what actions hurt the machine and how to feel for things that are not normal during the course of operating the machine. My own opinion - good operators know how to work their machines inside and out.

Upta-Maine said:

My own opinion - good operators know how to work their machines inside and out.

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Quite honestly this this far from accurate. The vast majority of what would be considered good operators know little about their machines. A small percentage may, but often what they think they know is wrong. Owner operators maybe a little better but still many of them don't understand their machines fully.

Ben Witter said:

Quite honestly this this far from accurate. The vast majority of what would be considered good operators know little about their machines. A small percentage may, but often what they think they know is wrong. Owner operators maybe a little better but still many of them don't understand their machines fully.

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Ben - Thanks for correcting my opinion. I appreciate it.

Was this problem ever resolved? Had the same vibration in cab when stopping. 2006. Was sold some bad fluid, that wreaked havoc on my hydraulics and that was one of the symptoms I was left with after bad oil was drained.

PTA - I just got the swing motor out on the machine and into my shop. I plan to get help rebuilding the motor from someone who has done it a few times before. It will be awhile before I get it rebuilt but I will continue to post my progress on this forum.

More to.come.

Scott

Uffex / FwF - I wanted to do a little "common sense" testing now that I have the swing motor on my workbench. Obviously there is something wrong if I have hydraulic fluid rising up and out of the dipstick tube. I'm not suggesting that there isn't some external (block drain line, dirty/wrong case drain filter, etc) causing this issue but absent of all of that I should be able to see if my lower seal is bad. I set the motor on my workbench and placed a clean/dry container directly below the main output shaft. Using a small pouring container I filled my drain port to the top with hydraulic fluid and left this for 48 hours. Tonight I tipped the motor up and found a decent amount of hydraulic fluid in the container....maybe 8-10 tablespoons. Considering that the only force pushing this fluid is gravity - I am fairly convinced my lower seal is shot. As you guys know I don't have all the tools to perform elaborate/accurate testing of the various systems but I'm hoping you would agree this "common sense" test is valid. Your thoughts? I will attach some pics.

BTW......I ordered a filter cutter that should arrive by this weekend so I can take a look at any debris in the case drain filter.

Good day Scottt
Common sense prevails that is a good start well done, I will try to get you that section of the manual I assume you do not have it. Movement in the shaft will result is seal failure so please check it out - the original fault you described of the noise should be fairly obvious, if there is little obvious damage suggests that the fault is most likely generated from the one of the valves. You could pressurise the motor to test the repair the pressure is very low 43 p.s.i max
Kind regards
Uffex

Uffex / FwF -
Sorry for the delay - been busy with my regular job. The filter opener that I ordered off Amazon arrived and I was able to quickly and easily open the case drain filter. Please keep in mind the previous owner of this machine claimed that he had gone through the entire machine and changed all filters/fluids just before he sold it so that "the new owner would be all set to go". I'm hoping that was truly his intention and not to try to hide anything that possibly could have indicated issues. So when we look at the results of my research please keep in mind I have only run the machine for less than 4 hours since this filter was supposedly changed.
The photo below is the debris that was filtered out (using a piece of the wife's best satin sheets) from the gearbox fluid below the swing motor. There is a good chance that not all of this debris was in the gearbox since the drain for the gearbox is in a very dirty area that is tough to avoid contamination when draining the fluid. I did smoosh/spread-out the larger particles to make sure they were not chunks of metal and in all cases they were clumps of greasy type material that very well may have fallen into the container I was collecting the fluid in. Also - the gears look perfect. I think the planetary gears and the gearbox are in good shape.

Now for the filter. I was really hoping to find an obvious "smoking gun" but was immediately disappointed when there was not a bunch of debris left-over on the cloth. However with a very close look I did find one fairly large particle, one medium and a few small flakes. All particles I believe to be made of brass (or a material that looks very much like brass). I was still a little disappointed not having more to share with you guys (and for my own piece of mind). So I decided to carefully remove the top and bottom sheet metal rings that make up the filter itself. I opened up the filter material from its original round, accordion configuration and stretched it out on the table with input side up. It took me a while but with a good light and careful examination I found more (and larger) particles of a brass type material caught in various places on the filter material. There were chunks and flakes. I gathered them all together on one blade of the filter and put a ruler in the picture to give you a reference (the ruler has divisions of 1/32"). With this find and the particles I found in the fluid itself and considering that there has only been a few hours run with this filter in place I would definitely say I have an issue related to a component that is made of brass or directly interfacing with brass....which leads me to my last bit of info in my next post.

I contacted the guy who was recommended by a friend to help me tear-down and analyse my swing motor to determine what the path forward to fixing it will look like. He asked me to explain in detail the issues. As soon as I got done he said he has seen this before and believes he has a theory on what went wrong to cause my two major issues (vibration and oil coming out of the gearbox dipstick). He said it was not on a Volvo but he has worked on swing motors from either a Cat or Komatsu (or maybe both - I can't remember) and has seen the exact same symptoms. He says there are 9 pistons in the swing motor that ride on the swash plate using small brass feet (called slippers) connected to the piston with a small universal type joint. He said in the motors he has seen this happen that one of the nine slippers broke. Because only one broke it is a vibration or thumping that increases with the speed of the rotation (exactly as mine does) as opposed to a constant noise or grinding if I suffered a more catastrophic failure with multiple pistons/slippers. He also said that when this happens it causes the swing motor to leak a ton of hydraulic fluid. This fluid uses the case drain circuit to return to the tank but when the condition worsens the case drain circuit is too small to handle the large amount of fluid that is now dumping out of the swing motor. When this happens it creates pressure on the inside of the case and the first thing component to fail is the main seal. It doesn't really fail as much as the rubber lip on the main shaft seal, which normally always points towards the fluid it is trying to hold back, gets hit with this pressure and it inverts the rubber lip so that it is now pointing away from the fluid (towards the gearbox). He said it will still provide and small amount of its original function but no where near the reliability of the original design.
This seems to fit my situation very well. I have evidence of brass in the case drain filter - the slippers are made of brass. I have a vibration that follows the speed of the rotation - a single piston malfunction would do this. I have fluid that is slowly building and coming up out of the gearbox dipstick - if my main shaft seal was flipped it would hold back some fluid but there would be an amount that leaked into the gearbox with no place to go but up the dipstick tube.
Oh...almost forgot to mention - the guy said he would be happy to have me join him in his shop to tear down the swing motor. He said he would show me the components as we went along and then, based on what we find, make a decision whether this swing motor is fixable or whether it may make more sense to look for a used or rebuilt one.

Your thoughts? Am I missing something that could introduce doubt to this theory?

Thanks,
Scott

Good day Scott
May I say it is easy to get lost in the haze of comments and we can loose sight of the original issue 1/ fluid coming from the swing transmission = over pressure from the drain line or motor seal failure 2/ Noise or vibration both from beginning the swing motion or stopping = either an issue with the swing brake releasing or a swing pressure issue both can be detected with a pressure gauge installed in the main line. I have taken a look at the wife's laundry but it is difficult to comment from this distance. In your shoes I suggest taking the motor unit to the bench splitting it down and giving it a close inspection but before taking that action to put a gauge in the line and observe what is happening at start & stop. Regarding be aware of what you are dealing with a contact posted a short video to me that makes a good example.
https://drive.google.com/open?id=18C7-U70OBHVSw9gIoqEirvhap0mHiUts
Take care
Uffex

The theory is strong. If a shoe is bad, odds are, there's nothing left of the rotating assembly to rebuild. Better off (cheaper) with reman exchange with a warranty. Had a travel motor blow like that. When I measured case drain it fired like a machine gun. The flow should be nothing more than a trickle. Rule of thumb is no more that 10% of max flow @ full throttle and full load.
Never turn down the opportunity for free education. If the guy is willing to walk you through it. I have a vendor here in Illinois who specializes in reman Volvo components. Competitive prices and a solid no BS warranty.
Not associated with, just had plenty of good experiences.

Thanks to both of you guys.

Uffex -
On my computer I click on the file name of the image and, when it opens, if I click again it allows me to zoom in to a decent granularity. I took as high a resolution photo as possible with my phone. Hopefully your computer allows some magnification.

FwF -
I have contacted H&R Construction Parts in Buffalo, NY. I have heard they are about the biggest around. I spoke with them and I'm still waiting for a call back as the guy was going to get me a "ballpark" price on a used swing motor. Once we have torn down the swing motor and determine the exact cause of the issues (if it is OK with you) I would like to ask you for the info of your place in Illinois. I get a feeling it is going to be pretty pricey to fix this (considering I use the machine for personal use and don't have a huge budget for repairs) but it is what it is. Big toys come with big price tags when things break.

Thank you in advance for the help,

Scott

Hi Scott
The image is a MP4 file I have checked it with moth Mac & Linux it works normally I am not so sure about other platforms. May be your platform is different not allowing MP4 files.
Kind regards
Uffex

Uffex, that was awesome. Guess he shoulda read the ops manual.