clunking in rear

[the_legend_1981]

I get a clunk when i hit bumps in the rear. I thought it was the spare so I took it off. The noise is still there. I'm thinking maybe loose shocks? how much play should they have?  And how much play should my axles have? Any ideas?

[Irish_Alley]

jump on the four corners of the truck. see if you can pin point where the sound is coming from

[the_legend_1981]

yeah if i jump on the back i can hear it. no help to look for it tho

[1980c10]

If the truck is lowered with shackles check to see if they are hitting the bed brace.

[Blazin]

Get under neath with a couple wrenches and check the shocks. If they arent lose check the bed. Shocks shouldn't have any play in them!

[1979C20]

Is your tailgate loose? My buddies truck clunks around a bit because of the tail gate.

[Irish_Alley]

does it clunk no matter what corner you jump on

[78 Chevyrado]

did it just start clunking for no apparent reason or have you done any work back there recently?

if you have a prybar, go under there and pry on this and that to look for play.  sometimes a rubber hammer can be quicker and easier too.  

check all the rubber parts, visualize the hole the rubber is in and see if the bolt going through it appears centered in the hole.  check the exhaust, gas tanks and bed bolts to see if theyre loose.  check for bare metal or clean spots that would show something contacting something else.

[the_legend_1981]

Could it be the catalytic converter? when i hit it there something loose inside...

[Captkaos]

Check the upper shock mount, they are know to wallow out...

[bake74]

     Also check your shackles, springs for cracks, etc. etc, anything you find loose will or can cause the sound.

[timthescarrd]

A bad cat will give you rattle/clunking sound.  The catalytic converter has this honeycomb looking brick inside of it.  When it goes out, that "brick" will break into pieces and rattle around inside.  You probably notice it most when accelerating if that's the problem.

[the_legend_1981]

My cat is rattling. Will it pass emissions like this? It passed less than a year ago and was only close on hydrocarbons.

[timthescarrd]

It probably won't pass if the cat is rattling, the rattling means that the catalyst inside has broken down into small pieces It's hard to say for sure though but my guess would be that since it has gotten broken down it will not be filtering as well.

[bake74]

It probably won't pass if the cat is rattling, the rattling means that the catalyst inside has broken down into small pieces It's hard to say for sure though but my guess would be that since it has gotten broken down it will not be filtering as well.

      If it is in one piece you might have a shot of passing, but the more it clunks the more it will break down.  I would plan on a new cat. before you go to get it smogged.