Soundproofing the B3030 Cab and found something interesting

[WaxMan]

Since I wanted to change the bushing on the Hydro pedal on the floor anyway, I figured it was a good time to think about sealing up and sound proofing the floor of my cab.
After some disassembly what I found was the whole weight of the Seat, Operator, Floor and Fenders rests on top of the transmission, metal to metal. (no wonder all the transmission noise in the cab)
If you look at the first picture the sound proofing was flatten to nothing you can see the outline and because of a weld not being ground off it was hitting the floor causing a worn out mark in the metal floor.(metal to metal)
Also the heads of two bolts were grinding into the floor as pointed out in the photos.
I ordered some Dynamat sound proofing to cover the floor panels, which now rings like a tuning fork when hit.
I want to find some rubber Isolators to place between that plate on the top of the transmission ( shown in the fourth picture) and the floor so all the weight will not be supported by the transmission plate metal to metal.
I can't believe all the weight, operator and all, rests on the transmission of the b3030 cab. Rests directly on the transmission for support. The transmission holds up the floor and nothing else.
I think I have room for a 3/4 inch rubber isolator to keep the floor off the transmission. The cab has four rubber isolators on the four corners But the center of the floor rests completely on the transmission for support, without anything to isolate the noise. Getting the floor off the transmission has to cut down on the transfer of noise, Metal to metal that is what I have now and most likely you do too.

 

[Bladehauler]

I've used old shock absorber rubber bushing for a lot of different things, do you think theyd work here ? most shops have a bunch laying around.

 

[WaxMan]

I've used old shock absorber rubber bushing for a lot of different things, do you think theyd work here ? most shops have a bunch laying around.

Thanks for that suggestion , Maybe, I know what you mean, I have used them many times on different projects. For this I'm looking for something much more soft and flexible about 1/2 to 3/4 thick, maybe a stack of a few 3 inch discs 1/4 of a soft rubber so all the weight is just on the rubber sliding discs. Any other idea's?

 

[Bladehauler]

any dirt tracks around ?? Sprint car rear tires are soft rubber with nylon cords and only about a 1/4 " thick when there wore out .

 

[My Hoe]

Subscribed.

 

[WaxMan]

Rather then putting a 2 or 3 inch mount , I'm thinking of this pad, so instead of the indent in the foam (shown in the first picture) where the cab rests on the transmission, the isolator will be in that area. This way the floor won't have any extra stress balancing on a mount, the weight will be as it was just now rubber isolator instead of flatten 3/8 useless foam. That metal plate in the second picture will be covered with the waffle pad. Anyone see any problems arising with that? Or would it be better to cut the pad into four squares to have less contact?

MASON Vibration Iso Pad, Waffle, 6x6x3/4 In - Vibration Isolator Pads - 2LVR7|2LVR7 - Grainger Industrial Supply

 

[Scrounger]

I would think the pad would be better in one large piece. How do you plan to attach it? Any adhesive at all?

 

[RFB]

Waxman,

How difficult was it for you to remove the cab, and how did you go about it?

Thanks

 

[WaxMan]

I would think the pad would be better in one large piece. How do you plan to attach it? Any adhesive at all?

I agree one piece, I think it will stay in place better. I was only going to cut out for the four bolts shown it won't slide off that way, so no adhesive planned at this point.

 

[WaxMan]

Waxman,

How difficult was it for you to remove the cab, and how did you go about it?

Thanks

I did not remove the cab at all, just the floor panels what you see in these pictures. Very easy to do, just a lot of bolts to remove.

I received the Dynamat Xtreme and the Dynamat 1/2 Dynaliner today. Much better then the foam that came with the tractor, heaver, more dense, water and rip resistant, all that old foam will be replaced plus all the other panels will now have it. I"ll post some pictures as I go if anyone is interested.

 

[Coyote machine]

I'd consider double sided sticky tape or contact cement to make it all stay where you want it to. Good solution. Realize that true sound isolation occurs when there is a void between surfaces so that sound gets trapped in the void and cannot transfer from surface a to surface b. You're effectively dampening the sound transfer in the padding vs. eliminating it by stopping the sound waves from getting across the 'void'.

 

[srs]

I'd consider double sided sticky tape or contact cement to make it all stay where you want it to. Good solution. Realize that true sound isolation occurs when there is a void between surfaces so that sound gets trapped in the void and cannot transfer from surface a to surface b. You're effectively dampening the sound transfer in the padding vs. eliminating it by stopping the sound waves from getting across the 'void'.

WaxMan, with what Coyote machine is saying is there a way to create a "void" between the surfaces so the sound is eliminated vs dampening it? Doesn't sound like there is enough room to create a void, which is a shame, but I can't tell by the photos if there is some way to create the "void".

 

[RFB]

I"ll post some pictures as I go if anyone is interested.

Yes please, I am very interested because I also want to try to seal up the cab from dust migration. Did you also have to remove the seat?

 

[WaxMan]

WaxMan, with what Coyote machine is saying is there a way to create a "void" between the surfaces so the sound is eliminated vs dampening it? Doesn't sound like there is enough room to create a void, which is a shame, but I can't tell by the photos if there is some way to create the "void".

The only place the middle of the floor touches anything is that plate on top the HST It's about 6 x 8 inches. That is what supports the floor in the middle. It cannot be made into a void. The only thing, which was my first though is put one 2 or 3 inch rubber motor mount there but that would put all the stress on that one spot.

Over time the floor might crack/ sag ? where the one mount is because it is not reinforced for that one spot.Then I thought of putting 4 rubber 3/4 dia. mounts hitting only in four spots. Then I found the rubber pad Using the rubber pad shown previously, it has many voids in the 6x6 area but it still covers almost the exact spot that Kubota designed the floor to be supported by, only instead of crushed foam bringing it down to metal to metal it will have that rubber piece with many void areas in the rubber.

If you zoom in on the rubber it has many voids and only the outline of the squares rest on the floor and HST. I think that is the best I can do for voids, unless someone has a better idea? I'm open for any suggesting.
The floor has to be supported some how, it can't just hover over the HST. It always has to end up in dampening somewhere in a horizontal application with weight on top. Only way it can be a complete void is vertical between walls or something where weigh is not a factor.
The more I think about it that mat seems like it will work pretty good. I ordered a 3/4 inch thick and a 3/8 inch thick 6x6 mat. I'll have it tomorrow. I think the 3/4 will work OK, but if not I'll used the 3/8 which I know will work because that is the thickness of the foam before being crushed to metal contact which probably happens the day it was assembled at Kubota.

 

[WaxMan]

Yes please, I am very interested because I also want to try to seal up the cab from dust migration. Did you also have to remove the seat?

Yes only because when you remove the floor panel the seat is just dangling there, it's only four bolts and gets it out of the way. You don't have to remove the sheet metal the seat is resting on. Although now that I see how nice the new soundproofing is I might redo that area too.
It's very easy to remove the seat and floor panels. This is not a hard project to do, How much will it deaden the sound is the question.
From what I have seen so far it should make a big improvement. This picture will give you a better idea of what has to be removed.

 

[Coyote machine]

What you plan to do should significantly dampen the sound transmission from the trans, and possibly from the engine as well, into the cab. It would be virtually impossible to eliminate all noise transferred because the cab has to be attached to the frame/chassis of the tractor. I'm sure you will notice significant improvement from your efforts.
Keep us apprised with pics of your process.:thumbsup:

 

[srs]

The only place the middle of the floor touches anything is that plate on top the HST It's about 6 x 8 inches. That is what supports the floor in the middle. It cannot be made into a void.

It's a shame Kubota did not put some type of floor brace or strut to support the floor to separate the it from the transmission. Regardless you've got some expensive and very good products to suppress the noise and vibration. Keep up the good work! Stanley

 

[RFB]

Waxman,

Thanks again for the photos; they help me to think through the process before attempting it. What area(s) do you think is/are responsible for the dust/dirt ingress?

Have you imagineered a solution for the dust issue?

Also, I did a search for Mason Iso products and found these:

http://www.amazon.com/s/ref=bl_sr_industrial?field-brandtextbin=Mason&node=16310091

 

[chim]

The link RFB posted is a good place to start. We do some vibration isolation with equipment. The one thing some people don't consider is isolating the bolts. If you have a machine that produces vibration, any bolts fastening to it should be isolated as well. If you insert a pad between the vibrating piece of steel and the part you want to isolate, the bolt should be installed using rubber bushings and washers so the bolt doesn't short-circuit the isolation material. Otherwise the bolt will conduct the vibrations from one surface to the next.

 

[srs]

the bolt should be installed using rubber bushings and washers so the bolt doesn't short-circuit the isolation material. Otherwise the bolt will conduct the vibrations from one surface to the next.

Chim, that makes a lot of sense but the only problem I see with the B3030 is that there isn't a lot of room between the bolt and the floor. Can you suggest a remedy for this? Thanks for your advice.