Dynamo Hummmmmm

[rusty_tlc]

Where's that humm coming from?

Zappa reference aside, we have a nice humm that starts at 65mph and escalates as speed increases. It also pokes it's head up around 45MPH (on my non tire corrected speedo) and drops off at just under 50MPH.

I had Spresso take the truck for a ride last week, he pretty much confirmed my suspicion that it is a drive line related problem.

As soon as time allows (we have family in town this week) the plan is to drop the front DS and lock the CDL then take it for a drive. If the problem is still there I'll replace the front DS and drop the rear, rinse and repeat.

If I still have a problem , I'll borrow Spresso's spline-less drive flanges and see if it is a CV axle that is the problem.

Stay tuned for further updates.


BTW: The first action was to have the tires rotated and balanced, sorry if that was your first guess too.

 

[spressomon]

I sure do miss Frank Zappa!

 

[TheFuzz]

I sure do miss Frank Zappa!

Frank Zappa --- Montana - YouTube

Poo Poo, Ta Na Na....and Poo Poo, Ta Na Na.

Epic. Good ol Frank.

And as usual I have nothing helpful to offer to the actual topic.

 

[bwallen149]

Just chased what sounds like the same issue. Your on the right track with dropping the dive shafts one at a time. Mine ended up being the rear u-joint on the rear drive shaft. The odd part is the old one felt perfect, as in felt smooth and zero play even when prying with a screwdriver. Only advice I would give is to start with the rear. From my searches on here, rear drive shaft u-joint issues seam more common that the fronts. Also, the rear is a little less protect, more chance of damage or knocking a balance weight off. Good luck...