Drone noise around 70 mph

[rdunagan]

I installed a 4" rough country lift about 2 or 3 months ago. didnt do the shim kit till last month and i just replaced all my u joints and carrier bearing and this "drone" started about a month ago. it rides fine with a slight vibration (which i think is the tires) but when you roll into the throttle and get to 75-and on it got a bad humming/droning noise. its not my exhaust system i know that nor is it the tires. u joints all look good but i cant figure this out. it only does it around those speeds and gets louder the faster you get. and i might mention you can feel it in the seat and in the petal when it does it. also it will do it every time. i cant tell if the shim kit is causing it or if its the axle or what. its driving me nuts being that i have replaced the u joints and carrier bearing

[2004 F250]

Hey my 2004 does the same thing.. I noticed it more after the 6.5" lift, i am positive its the drive shaft angle and pretty sure balancing the drive shaft would help, but cash is tight, so I will live with it.

[lenzhotrod]

Is youir driveline phased properly?

[2004 F250]

Hello, I just got back from a 250 mile round trip and the noise is getting worse.
I had a shop install the lift back in 2004 after I purchased new, and it spaced the drive shaft center support lower, but I dont think its phazed, I will crawl under it this evening and see if the transfer case output and the pinion are parallel. I noticed yesterday that in neutral with the ebrake set that there is alot of rotational play at the pinion flange , I am thinking maybe the spider gears are toast? I am hoping that that is all it is, since I am broke and out of work... 87,000 miles on the truck, ford rebuilt the limited slip at 60,000 miles.
Thanks for the help!

[2004 F250]

Sorry, didnt mean to hijack this thread, so I started a new one under driveline phasing. .