SO I was driving yesterday and the beast just randomly starting shaking at 45 mph. It is not present under 45. It is not violent, kinda feel like a wheel is loose or something like that. I do not feel it in the steering wheel. I crawled under her and both shafts are solid (front one is new, 1 year). I rotated the tires and checked the hubs, all looked good. Has anyone ran into this or have any ideas?

2003 D2
4.6l
2" lift
New brakes, front to hubs 1 year old

 

I'd double check the front shaft again.

 

My 03 did this at the same speed and has a lift on it too.

Don't remember the brand, but I swapped the aftermarket front drive shaft I had out for a Tom Woods one and issue solved.

 

I think I am going to just order a Tom Woods DS. I have a cheap aftermarket one. Last thing I need is that thing to pop.

 

things that can shimmy/shake
wheels
d-shafts
harmonic balancer
sometimes the torque converter can oscillate