M1008 buzzing bed

[rdc0000]

Do the beds on these trucks just buzz and rattle at idle or am I missed something? I've checked to make sure nothing is touching the frame. The engine, trans mounts are all good. The exhaust is not touching anything. The buzzing is on the bed and the tank so the vibration is frame related. Anyone ever use some isolators to stop the buzz? I know, OCD.

I further researched harmonic balancers and found that the AC Delco is not available and I am anti CCP so I don't really want one any way. These are what I found and I would like your opinion on their quality. All are about the same cost and made in Australia. I am not sure about the Pioneer but, the seller said AU.

ATP 102059 (AU)
PIONEER DA-3790 (AU)
DAYCO PB1102N (AU)

 

[WWRD99]

My exhaust buzzes pretty bad probably because it's rusted inside but the bed sides will buzz some if the idle hits a certain speed on mine too but it's mostly the muffler on mine. As far as the balancer goes you are right that the gm replacement is not around right now and not sure if it will come back. I bought my last one in October of 2021 for 94$ and figured I could get another when I needed it!! There were tons out there then. I can't say if any of the ones you listed are any good but the high end Fluid damper brand is available but expensive. You can get the Dayco in the US too those are at Rock Auto.

 

[rdc0000]

Fluidampr is $564+freight+tax. Nope.

 

[LT67]

Check the skid plate below the fuel tank. It'll buzz like crazy if it gets loose

 

[WWRD99]

Fluidampr is $564+freight+tax. Nope.

Yeah that's nuts plus you don't really need all the tech that it provides...I'll look through some of my surplus guys and see if they have any.

 

[LT67]

Fluidampr is $564+freight+tax. Nope.

I had the balancers on both M1008 trucks replaced with OEM units from Dorman. They work just fine..

 

[87cr250r]

If you want a lower cost non-Chinese alternative to Fluidampr, Dayco sells a made in Australia damper. It's still a rubber type but half the price of Fluidampr. I had a vibrating bed but I haven't run the new engine yet to tell if this makes a difference.

 

[adf5565]

Is your idle set too low? I had to bump mine up a little to ~700 which greatly reduced the rattle as the bed was vibrating as well. I put in a fluid damper beforehand, it helped but wasn’t a miracle either.

 

[M813rc]

Check the skid plate below the fuel tank. It'll buzz like crazy if it gets loose

I second the skid plate check. It took me a while to track the buzz on my M1028 down to that, because it really sounded like it was coming from somewhere else.

Cheers

 

[LT67]

The easy way to check the skid plate is to put your foot on the plate while the truck is running and parked. If the buzzing noise stops, you found your problem

 

[LT67]

My 86 M1008 developed a buzzing noise last year. I knew it coming from somewhere around the rear drive shaft. Turns out the bushing inside the tail end of the transfer case needed to be replaced