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loud Ratcliffe hydro

georgeofdesert

Member
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Trying to quiet this thing down. Runs about 90 db at idle in the cab.
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Pump under floorboard.
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Wrapped with 2+ layers of 80 mil butyl foil covered self adhesive "sound deadener". Didn't do much.
butyl 80 left.JPG

Made a "tester " for different types of material. Foam types didn't do well. Mass loaded vinyl sheet and plain old rubber stall mat did best.
The mass loaded stuff I bought was 1/4" thick and fairly stiff, about $6 sq ft for the 2 lb. stuff. ;the stall mat is cheap but heavy, about 4 lb sq ft. Baseline shown below is 84 db. 2 layers Mass loaded vinyl gave 74.8 db with the same weight as 3/4 inch stall mat which did better at 71.8. Stall mat is also much cheaper.
2 layer .25 in.  MLV.JPG
stall mat.JPG

baseline.JPG

Cutting and fitting the mats to fit between and around things.
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Ended up here.
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And then started crying
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Melensdad

Jerk in a Hawaiian Shirt & SNOWCAT Moderator
Staff member
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I sprayed the inside of my cabin with a 2 part epoxy that is similar to Rhino-Liner or Line-X. That stuff is a fairly hard rubber like material that is used inside the beds of pick up trucks. It helped a bit. One thing it does nicely is seal panels with a thick layer to help stop sound infiltration, helps reduce some of the vibration noise too. It is NOT a sound deadening material but it helps and looks good too. You can get it in various colors and even custom tint it to match the interior paint color of your cabin.

My best guess is that you will end up combining several techniques of sound deadening, rubber isolators, sound deadening materials, etc.
 

georgeofdesert

Member
GOLD Site Supporter
My best guess is that you will end up combining several....
Exactly right. I went into this project thinking I could pull it off with a tube of caulk and an old yoga mat lol.

more test results. both of these were sold as "sound and heat insulation".

150 mil foam.JPG
150 mil closed cell PE foam

300 mil foam.JPG
310 mil foil backed foam

Baseline still 84.
 

Cidertom

Chionophile
GOLD Site Supporter
The other issue you may be dealing with is conducted noise through frame that then re-emits in the body. Check to see if isolation mounts, flex couplings etc, may have been compromised or removed, or never used.
 

georgeofdesert

Member
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Huh....you may have something there. Never noticed any static oddness, but levering or prying while running might tell something.
 

georgeofdesert

Member
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The other issue you may be dealing with is conducted noise through frame that then re-emits in the body. Check to see if isolation mounts, flex couplings etc, may have been compromised or removed, or never used.
Didn't notice anything with powertrain mounting, although the way all that hose is shoehorned in there it is pretty jammed up.
Unfortunately no flex drive coupling....wish there was, with a clutch.
Did notice pieces of tub bottom vibrating away, unanchored where cutouts were made. Don't know if it is part of the noise problem but needs secured anyway. Thanks for pointing me towards that.
IMG_7150.JPG

L:eek:oking up. Large piece is bottom of tub, attached to vertical sidewall at left, cut off at right.

PO uploaded video of this as "Ratcliffe Tractor", off the tracks. Kid is a smoother operator than I am.
 

georgeofdesert

Member
GOLD Site Supporter
Came across this stuff at Menard's.
IMG_7198.JPG

Seems to work as well as the Mass Loaded Vinyl and is alot more flexible. Cost about $4 sq. ft. Not sure if it is the material or the topography that makes this work. It is a bit quieter on the bumpy side. Pics show the sideboard on the passenger side, engine running.
IMG_7195.JPGIMG_7197.JPG

Plan is to use plastic push pins to hold some to the sides of the tub. Testing some paint to see if color change is an option.

If you need floor mats anyway.......
 

georgeofdesert

Member
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Edit: Came across this stuff at Murdoch's

View attachment 139216

Seems to work as well as the Mass Loaded Vinyl and is alot more flexible. Cost about $4 sq. ft. Not sure if it is the material or the topography that makes this work. It is a bit quieter on the bumpy side. Pics show the sideboard on the passenger side, engine running.
View attachment 139217View attachment 139218

Plan is to use plastic push pins to hold some to the sides of the tub. Testing some paint to see if color change is an option.

If you need floor mats anyway.......
 

alryA

Well-known member
George, seems you are on the right track to lessening the sound. On the floor of the trail bully's I operated, was thick and heavy rubber like mats that may have been 1" thick. Man they were heavy. In these PB 400's, you nearly had the 375 turbo charged engine in the cab with you, but was one of the least noisy machines I ever operated. Like melsdad says, reducing it will take multi levels of modifications.
 

georgeofdesert

Member
GOLD Site Supporter
Yeah, it is quite the rabbit hole. Never appreciated the "treatment" subtleties (absorb,reflect, deaden). I think the foams are overwhelmed by such a strong point source. Was disappointed by the MLV. It is nice to be able to measure sound level changes. There are apps, but I bought this meter for under $20.

The engine/pump mount is simply donuts with a bolt. If it is ever pulled that will be upgraded.

Shame to have to add dead weight. Removing 30 lbs of old steel aux fuel tank makes me ok with it for now. Were the mats in the PB 400's factory?
 

Snowy Rivers

Well-known member
Chasing noise can be a real problem.
Back in my days working building mill equipment we had to make sound enclosures for some of the machines.....A hole the size of a dime can let in tons of noise......

We used a rubber sheeting that had barite in the rubber (Very dense material) . And the egg carton like foam helped where it could be used (Operator cabs)

Conducted noise as mentioned can be tough to suppress.....All the drive components must be isolated from the frame...

Like automobiles....The engine/power pack is isolated from the frame and then the cab is isolated separately from the frame.

Any expanse of sheet metal can "Drone" and transmit noise.....

Good luck with quieting the beast.....noise can be annoying to say the least.
 

Snowy Rivers

Well-known member
I was looking at some pics of the machine a bit ago..
I had a similar type 6x6 rig ....The cab is the chassis and this is going to make dampening the noise much harder to do....You are literally sitting right in the machine itself.......

I think that the egg carton foam glued to the interior walls of the cabin (Where practical) along with what you have done will likely be about the best you can hope for.....
 

georgeofdesert

Member
GOLD Site Supporter
Well, there are gaps in the armor, alright. That will be added to the list. But I"m now learning that I'm chasing symptoms, so thanks to the greybeards for that.. Better isolation of the power pack would have been a good thing. Don't know how the builders missed that, my problem now I know, but otherwise the drive has been solid. So the hydraulics guy knew what he was doing, and the systems integration people blew it.

But it's quieter with the doors closed than open, so that's progress. Now I'm wondering if I really need the dual glass packs.
 

Snowy Rivers

Well-known member
Anything you can do to cut any and all noise will NOT HURT a thing.

We had a small MAX 4 six wheeler a few years ago.....It had a single cylinder air cooled engine with a planetary type drive.

We added a full roll cage....and then a soft top....OMG the noise was just nasty with the rag top on.

Full and total isolation of the passenger compartment is optimal to get anything nearing QUIET.
 

georgeofdesert

Member
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Wondering why the instrument panel was so loud...

IMG_7202.JPG

Realized the hydraulic tank mounted behind the dashboard was yelling...
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Covered the inside face with mat.
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The pump suction line appears to be a shop fabricated high pressure hose about 10 inches long. Must be turning the tank into a drum. Conducted noise others have warned of. Don't know if it is the rigidity of the hose or pulses thru the fluid. Turns out that high pressure hose is a poor selection for a suction line anyway. Needs redesign.
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Blue hose is suction line.
Also added mat to sideboards
Wrapped hose with painted mat for now.

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So the thing is still loud but no longer painful. Next season --overhaul powerpack mounts, replace (reroute) suction line using flexible hose.
Well, all summer and $300 for 12 stinken decibels, sigh.
 

georgeofdesert

Member
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lol Certainly would have been a more efficient solution.
I should have added a snark tag at the end above. 12 db is alot of energy.
Wouldn't want to discourage anyone from trying....there are apps and meters are cheap so it's easy to see what works.
 

mlang2005

Member
Is it engine noise Or hydraulic whining?
without hearing it my guess is the hydraulic pump is cavitating. Hydraulic tank loud? Foamy oil?
Hydraulic pump should not be loud, particularly if it’s just running no load.
Does it get louder or quieter when a function is performed?

if hydraulic is suspected
I’d be investigating the oil supply to the pump. Plugged/restricted suction screen or Ive seen separated suction lines, foreign object in the suction plumbing restricting flow.
pull the hose off at the pump and let it flow into a bucket, it should really pour out fast.
you mentioned the suction hose It’s possible someone undersized the suction hose, generally the suction will be much larger diameter then the pressure line.

if all that checks out could be something up with a relief valve or misplumbed or a dozen other things lol
 

georgeofdesert

Member
GOLD Site Supporter
Mostly hydraulic noise. Oil seems OK. Never could hear the exhaust tone until now. I don't think it is cavitating, it has a charge pump gauge that registers about 100 psi.
The way I understand the system (if anyone has a book plea$e jump in) most of the flow just recirculates between the pump(s) and motors, some flow being bled thru screens and cooler back to the tank. No suction screen.

Plan is to overhaul suction line, that will hopefully get that bug out of the loop.
 
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