Truck Cab / Body mounts

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Old thread revival, sorry guys.
I'm just wondering how much a rubber mount dampens much when a bolt/washer still contacts a hard surface?
Wouldn't it be better to find a urethane or rubber with impregnated stud integrated in it.........okay. Let me think this through more. Guess that wouldn't work.
How about this....layer by layer.

Bolt, washer, rubber biscuit mounted on top of body mount flange, another biscuit, frame, another biscuit, washer, nut.

I know that's a lot, but wouldn't this allow more verticle movement and isolation between the steel body mount surface and steel frame surface?
Perhaps I'm over thinking this but I would figure just the bolt would transfer lots of vibrations through the body even with a single biscuit in place.
 
Something I have been wondering about as well, jml ...

When I took my '94 fullsize Chevy pickup apart, the body mount rubbers (4) were about twice as thick as the bed mounts (3 per side), and bolt-washer-mount-rubber-body-washer-nut. The bed rubbers are about 3/4" thick and the body almost 2".

When the '49 International body goes onto that frame, there is no way any of the original mounts are going to line up, so your idea of layers might come in handy for this with bolt-washer-thin rubber-frame-thin rubber-body-thin rubber-washer-nut. Oh shoot, I'd be one rubber short (don't say it!). May be over-thinking this too ... Don't really want to have to keep an eye on metal to metal wear (as mentioned) and want to drive this thing a lot !!!
 
Something I have been wondering about as well, jml ...

When I took my '94 fullsize Chevy pickup apart, the body mount rubbers (4) were about twice as thick as the bed mounts (3 per side), and bolt-washer-mount-rubber-body-washer-nut. The bed rubbers are about 3/4" thick and the body almost 2".

When the '49 International body goes onto that frame, there is no way any of the original mounts are going to line up, so your idea of layers might come in handy for this with bolt-washer-thin rubber-frame-thin rubber-body-thin rubber-washer-nut. Oh shoot, I'd be one rubber short (don't say it!). May be over-thinking this too ... Don't really want to have to keep an eye on metal to metal wear (as mentioned) and want to drive this thing a lot !!!


I'm scratching my head now trying to remember the mounts on the cab of my 03 dodge. I know ther have multi layered isolaters but can't remember how it went. I don't think it was this complicated, but I certainly remember at least two isolaters.

P.s. I'd rather be one rubber short then one nut short. For the bolt, ya know. Wouldn't have a good mount that way :rolleyes:
 
LOL ;)

I was just reading a thread on another forum where a guy had the rear body mounts rust through on a Chevy pickup and he was doing a repair and asking for advice. Seems he went with a "simple fix" using BIG washers on both sides of the mount to clamp back onto that surface, and had upper and lower rubber pieces with a sleeve. One fellow was saying it was mostly to keep the body from coming off in an "incident" and that some flex was good for such, but also for noise reduction and comfort. I got lost when the discussion got into engineering and over-complication. K.I.S.S. Hopefully one of the sages from THIS website will have something we can understand!
 
K.I.S.S. -
Bolt the body solid to the frame.
Isn't that what any unibody car is like? Vibration damping is by rubber mounting the drivetrain and suspension components.
Fancy rubber body mounts on trucks were made to quiet them down to make them more civilized and widen their appeal to the masses. Remember the old Ford ads, "Works like a truck, rides like a car"?
You wouldn't want too much flex between body and frame as it could cause unhealthy movement in the steering linkage - lots of factory setups compensated for this with the steering rag joint.
I've always solid mounted the bodies on my builds, my thinking is that a decent frame solidly bolted to the body will create a more stable whole with more predictable handling - if the structures are properly built, there should be no cracking.
Just my 2 cents worth....
 
Good explanation, thanks! A solid mount to the frame also takes away that uneasy "mushy" feeling in corners which is more likely the body rocking on old mounts rather than suspension and chassis slop. So as long as the suspension bushings are good, then there is really no need to worry. Let them do their job and get more connection via the seat of the pants. I like it !!! :)
 
I don't care for the solid mount idea. My brother has a 40 International rat that has a solid mounted cab. For one thing, it is loud. There's no headliner, carpet or anything else to dampen the noise. Everything little sound/vibration from the chassis reverberates right into the cab. Along with the open headers, it can drill right into your head.

The bigger problem is that it's a 2 piece cab. The 2 pieces join at the beltline. As the pickup has flexed for these number of years, it has loosened the cab up and broke some braces in the back of the cab. Rubber isolators are the way to go to isolate some noise and to make your cab last.

Pickups are working machines. They were built to drive through country ditches and to chase coyotes through the pasture. They are built to flex more than what a car needs to. That's why the cab is separate from the box. Look at some of those driveways you have to drive into. They can put a terrible twist and torque on your ride. You need the rubber isolators to absorb some of that twisting or you will be driving a rattle trap pretty soon.

We are building a 47 Ford bobber right now and are going to use Jeep rubber isolators. The brackets are very basic and an easy build.
 
I used conveyor belt about 3/8" thick between cab and frame mounts on my 31. The pipes exit right behind the cab where they make 90 degree turns out to the outside and just ahead of the rear tires. It's so loud, I can't tell if it helped any body noise or not. I placed them mostly so as not to have any vibration cracks in the cab. I don't feel alot of vibration in the cab sheet metal and no rattles that I can hear...
 
I like to use the rubber rollers for boat trailers that the boat rides on, hole is pre drilled, theyare about 2" round, cut with a hand saw to desired thickness.
 
This is something a little different but it's cheap and has worked for me. I buy the cheap plastic cutting boards from WalMart. I've used them for spring spacers, body mounts, shims, etc.......... Heck I even used the smaller ones to make the fuse panel in my truck. Oh and as a foot pedal extension. Worked great...... :rolleyes:
 
See............ :cool:
 

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This is something a little different but it's cheap and has worked for me. I buy the cheap plastic cutting boards from WalMart. I've used them for spring spacers, body mounts, shims, etc.......... Heck I even used the smaller ones to make the fuse panel in my truck. Oh and as a foot pedal extension. Worked great...... :rolleyes:

I hear ya, when ever they go on sale I buy a hand full. They come handy for a bunch of things, using a hole saw you can make any size spacer, they make great backers for trailer license plate to protect the plate from rock rash etc
 
Factory body mount bolts aren't supposed to be zinged in really tight. If you remove any of the GM truck bolts they have Lock Tite on the threads, on Ford trucks the bolts screw into the mounts on the front and have a nut on the top, all to allow some twist movement.
 

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