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73-87 Chevy _ GMC Trucks => Body, Glass & Paint => Topic started by: bladerunner on September 01, 2011, 07:25:53 pm

Title: Bed Rattles
Post by: bladerunner on September 01, 2011, 07:25:53 pm
Hey everyone-

So the truck is all inspected and I have been driving it back and forth to work all week, loving it!

One thing however is the bed has a pretty significant rattle to it.  The bed is new and was installed maybe a year ago by the PO.  My father-in-law believes the noise (which is pretty annoying on rough Maine roads) is due to the fact that there is no padding (or some other absorbing material) where the bed meets the frame.  He suggested I spray some expandable foam in between the gaps. I'm not sure about that.  What do you guys think?
Title: Re: Bed Rattles
Post by: muddpuppy01 on September 01, 2011, 07:47:58 pm
I would check to make sure you have bushings in the mounting spots and check to make the bolts have not back off some
Title: Re: Bed Rattles
Post by: VileZambonie on September 01, 2011, 09:16:04 pm
Yeah, no.

Is this a rattle over bumps? Is the converter heat shield loose? Common problem.
Title: Re: Bed Rattles
Post by: bake74 on September 01, 2011, 11:38:52 pm
  He suggested I spray some expandable foam in between the gaps. 

     Why are there gaps between the bed and frame ?  If the bed is loose it will bounce, but I am with Vile, the more common problem is the heat shield.
Title: Re: Bed Rattles
Post by: thirsty on September 02, 2011, 07:01:02 am
Did you check to see if it is coming from the tailgate? I wouldn't use spray foam, it will hold moisture and rot what it is on.
Title: Re: Bed Rattles
Post by: SNWBLL on September 02, 2011, 08:46:16 am
My bed rattle was due to loose shocks. I tightened them up and no more rattle.
I do have a bit of squeeking in the suspension when going thru odd dips and turns.
Title: Re: Bed Rattles
Post by: bladerunner on September 02, 2011, 01:59:05 pm
I wouldn't use spray foam, it will hold moisture and rot what it is on.

Exactly my thought.

I have tried to isolate the noise and am fairly certain it is the bed. Its one of those situations where multiple sets of ears would be real handy.  I expect a fair bit of road noise in an old truck, but this is something else.  Looks like I will first check the bushings and the shocks. I'll keep everyone posted and thanks again!

Title: Re: Bed Rattles
Post by: beastie_3 on September 02, 2011, 02:00:41 pm
Shake the bed and bounce on the bumper.
Title: Re: Bed Rattles
Post by: bladerunner on September 02, 2011, 06:06:30 pm
 
Why are there gaps between the bed and frame ? 

This is what I meant by gaps:

(http://i872.photobucket.com/albums/ab289/bladerunner1337/bed_diagram.jpg)
Title: Re: Bed Rattles
Post by: bigchevyc30 on September 03, 2011, 12:22:05 am
i would think those gaps are normal since the bed has the ridges
Title: Re: Bed Rattles
Post by: Blazin on September 03, 2011, 01:13:53 am
Easy enough to tell if its them. Take a hammer and bang on them some, Se if you get the rattle?
Title: Re: Bed Rattles
Post by: bladerunner on September 03, 2011, 06:40:05 am
i would think those gaps are normal since the bed has the ridges

Yeah, they're normal, my father-in-law wanted me to spray foam in them to cushion the bed, which seems silly to me.
Title: Re: Bed Rattles
Post by: bobcooter on September 03, 2011, 06:45:32 am
If it's squeaking from the rear your shocks may be damaged.  Get someone to stand in the bed and bounce up and down while you get on the ground and listen closely. If it's from the front, grease your front end components and see if it goes away.
Title: Re: Bed Rattles
Post by: bladerunner on September 28, 2011, 08:25:30 pm
One thing I have noticed is that if it is cold out, say in the morning, there is no rattle. The rattles is only present when it is fairly warm, say mid 70s (which is warm for Maine).
Title: Re: Bed Rattles
Post by: bake74 on September 30, 2011, 09:46:10 am
 
Why are there gaps between the bed and frame ? 

This is what I meant by gaps:

(http://i872.photobucket.com/albums/ab289/bladerunner1337/bed_diagram.jpg)

     I am sorry, but does this strike anybody else that in that picture, the cross member is welded to each section of bed.  Did you check like blazin said under your truck at each cross section to see if the welds are broken.  Heat causes metal to contract while cold expand, maybe it is that simple, you have a spot or couple that are cracked and when it is hot enough to contract they can move a little and bounce, metal on metal ?
Title: Re: Bed Rattles
Post by: bladerunner on September 30, 2011, 10:42:14 am
Great idea bake!  I will check that out today and see if there are any broken welds. I'll keep you posted and thanks!
Title: Re: Bed Rattles
Post by: bobcooter on October 03, 2011, 09:13:30 pm
Actually heat makes metal expand and cold causes metal to contract. Probably just a typo.