Driveline question

[PaulJohnson]

I have a 2007 QTD 5. 9 and it has the 70mph or 1800rpm vibration. I have been reading around on this and many peaple have been saying that extending their drivelines and adding a double cardan joint has fixed their problems. Anyone else found anything to fix this vibration problem. I do have a 6 in. lift but it was making this noise before I lifted it. Dealer says it is driveline drone and it is normal. BS!

 

[sag2]

If you have a six inch lift you might be running into 2nd order vibration which is angle related. If it was there before the lift and is exactly the same, it is most likely first order vibration or balance related. First thing to do is pull the front shaft and see if it goes away or is better. Once the front shaft is eliminated as the source you can balance the rear. If it goes away with the front shaft out then use the procedure below for the front shaft after doing it for the rear. Get two hose clamps and start with one clamp with the head of the clamp next to any of the weights at the rear of the rear shaft. Mark the spot and drive it. Is it better or worse? Move the clamp 90 degrees and drive again repeating every 90 degrees until you are back to the starting point. I like to number each 90 degrees 1-4 and then I can go back to the best spot. Next repeat the process with the front of the rear shaft (take the clamp off the rear) and record which spot is best. If you're getting an improvement then take two clamps and split the clamps apart some at the spot that was the best. Move them several times again noting better/worse. Repeat again for the front of the shaft and you have just balanced the shaft on the truck. Then leave the clamp(s) in the best place and paint mark them for reference in case they get disturbed. When I do them I try and get two exits on the freeway about a mile apart and just keep getting off the exits and moving the clamps when I'm in a safe spot. Your fine unless you pull the shaft, then make sure you mark the rear yoke to joint position and the front yoke to output shaft position or you will have to repeat the process. Take a piece of cardboard and a 5/16 nut driver and you can get it done in about an hour.



EDIT-find your friendly Snap-On, Mac, or Matco dealer and buy a 3" long or longer #40 Torx bit to remove the front shaft. You will be glad you spent the money in the long run.

 

[PaulJohnson]

Great info!!!! My truck is a auto, and I pulled the front shaft and found that it made no improvement. I will try to balance the rear today with thr method you spoke of. The drone I have does it as soon as I shift into overdrive and it stop if I let off the pedal. It is driving me crazy now.