[613Duramax]

Hey just joined and planned to post one question at a time

but

I have a 2001 GMC 2500HD with ~183000kms on it. When driving slow (40 to 60 km/h) over bumpy roads, I get an awful banging sound from the back end. Sounds like pieces of metal being hit together. Don't notice it at higher speeds, but it could be drowned out by the wind etc...

Any thoughts?

thanks

 

[ob_1jr]

Check your spring stack. the overload springs should have a rubber/plastic disc on each end to isolate them from hitting. If they are missing, go to gmdieseltech.com and buy the rubber o-rings for the spring stack. the stock ones just fall out of place.

 

[jdp_509]

Do you leave your reciever hitch in the socket? It rattles pretty bad on bumpy roads.

 

[613Duramax]

I don't leave my receiver hitch in. I will get those o-rings.

I will let you know thanks.

 

[idrivebowtie]

does it do it when you put the truck in drive and reverse from a stop?

 

[n0useforaname]

My truck did that when I bought it brand new....and it ended up being a mixture between what OB1jr said and my running boards. So if you have running boards...you might want to check them...it rattled my whole frame!

 

[613Duramax]

does it do it when you put the truck in drive and reverse from a stop?

Not sure what you mean. I have not tried reversing over the same bumps that cause the banging sound when I am driving over them.

I did check my overload springs and it looks like the plastic disc is missing. Ordered some of the o-rings and we will see if that does the trick.

 

[ob_1jr]

Not sure what you mean. I have not tried reversing over the same bumps that cause the banging sound when I am driving over them.

I did check my overload springs and it looks like the plastic disc is missing. Ordered some of the o-rings and we will see if that does the trick.

I believe he was talking about noises it would make when you put it in drive and reverse. That could mean something else. While you are waiting, you should check and make sure the rear shocks are tight too. I had that happen with the first set of replacement shocks I put on.

 

[613Duramax]

The sounds don't happen when I shift into drive or reverse from a stop. Thats seems (and sounds) normal. The sounds only occur at around 40 to 60 km/h. Any slower and it doesn't happen and any faster it doens't seem to happen.
I am still running the stock shocks, but I will check them for tightness. I will also check my running boards. The bolts are tight, but they may be pushed up against the frame and making some sounds.

 

[613Duramax]

I have orderd my rear spring insulators from Merchant. BUT I had the truck loaded up with some bricks last night and the overload springs were compressed so they were touching the rest of the springs and I was still getting the sound. It didn't happen as much but it was still there. It was more like a rattle rather than a banging sound.

Any other thoughts? I have not checked the shock bolts, I will tonight.

 

[ob_1jr]

It could still be the shocks or even the overloads when the truck comes off the over loads. Have you checked to make sure your spare tire isn't moving around? That is pretty much all I can think of.