Shaking at 70-75

I have had this shaking for awhile now. Sometimes It seems worse than other times. I have replaced the carrier bearing, made sure the tires are balanced perfectly, my u joints look and feel fine. I'm thinking it's the rear transmission mount maybe ? It's an 02 with 183000 miles.. What do you guys think ? I forgot to add.. The shaking feels like it's in the rear .. The wheel doesn't shake

 

Move both back tires up front, see if the vibration moves as well.

 

Good idea I'll try that tomorrow and see what happens

 

Any other things I could try ?

 

Ive got the same thing, figured its just the MTs

 

look for weights that may have fallen off the drive line, but that would cause it to shake at other rpms as well.also drive line faze is important usually your yokes should be exactly say one is from 12 o clock to 6 o clock the other should be 3 to 9 ..anyone taken off your drive line without knowing what theyre doing?

 

Been chasing this for a while too.

 

think about it the only things that spin is flywheel,to clutch,to trans input bearings gears output bearing,drive line ,carrier bearing pinion bearing to pinion shaft differential gears to differential spider to both axle shafts wheel hubs and drums and wheels ,,,my best guess is tires. all others would shake at other rpms exept all rear axle components which have never been known to cause vibration...hope you best of luck..

 

if you have at or offroad tires that more then likely the speed at which yhey go out of balance for a few mph then go back in due to rotation and how they balloon

 

and try changing lug nuts sounds dumb but my grabbers would shake on the highway at about the same speed, but at 100,000 lug nuts are supposed to be changed due to stretch. i installed gorilla lugs and it helped

 

does the vibration go away when you let off the gas completely? my truck just started vibrating at 70mph turns out to be my double cardan joint.