I own a 2004 3500 Dually Cummins 5.9L with 87,000 miles. I just recently (86,500 miles) had the front drive line and both axle U-joints replaced because at highway speeds the truck vibrated. The vibration is still there but not a noticeable. Now I have a heavy vibration/shaking at at low speeds (about 20 mph and lower), park idle and stops (still in drive). I seem to remember that normal idle was around 1,000 rpms but now sits at 750 rpms. Is this from the idle being to low or is something else causing the vibration/shaking? I live in Alaska and and bought the truck here new.

 

Normal idle is around 750 - 800, so you're good.

My first guess, if it's shaking at idle, is that you have an injector going south.

Please tell me that you don't live near Anchorage and have to deal with that shady azz dealer that is the only one within 400 miles or some crap.

Because honestly, your best bet right now is the dealer. The truck needs to be hooked to the StarScan or StarMobile and they need to do an injector kill test and figure out if that's the cause.

I'm betting that you'll find one, or more, of them is getting ready to die.

 

I live in Anchorage now and there are two Dodge dealers in town now. When in Fairbanks, always to truck to Gene's and always received good customer service.

Well looks like Anchorage Chrysler is getting a call tomorrow morning.

For some reason today was not as bad as the past few. It still vibrated/shaked but not as rough. Weather today was cooler with over cast and precip.

Thanks for the advice Coal Train.

 

That's the one I was thinking of.

You are THE first person that I've heard say that.

Everytime I've heard Gene's mentioned, it was something scathing.

 

C.T., thanks for the advice. The dealership was a little suprised when I told them what needs to happen and you were on mark. Sorry took me so long to get back. Anchorage Chrysler replaced all 6 injectors along with the fuel filter (to which I had to pay). The vibration and shaking is gone at low speeds but still have a vibration at 65-70 mph. Coming up on 90k service and will hae the tires balanced and rotated. Will see if the takes care of the high speed vibration.

 

Glad to hear you got the injectors taken care of.

That 65-70 MPH shake is more than likely tires being out of round......not out of balance, out of round.

Usually, if the shake is in the 5 - 15 MPH range, it's a u-joint or a carrier bearing. If it's in the 45 - 60 range, it's usually a tire out of balance. If it's 55+, it's usually a tire that is out of round.