Weird shaking at 60+ mph

So i noticed it for a while now and I really interested in knowing whats causing this shaking. When I drive on the freeway I notice that my passenger seat starts to shake a like and same with my shifter knob. I can also feel it on the floor when I have my left leg on the floor. Does anyone know whats causing this to happen?

 

A shake in the steering wheel is usually an out of round tire or an out of balance tire in the front. A shake in the seat or the floor is usually from the rear. I would have your tires checked first. Also, check your shocks to make sure they arent shot and then if all of that is fine, check the balance of your drive line.

 

I just got my tires rotated a couple days ago. so that's not the thing. the shocks are fine. and how would i check if my balance of my driveline?

 

was it doing the shaking before you rotated your tires? Could very well be an out of round rear tire/out of balance rear tire that was moved to the front

 

yeah its been doing it for a while now..

 

Did the shaking change at all after the rotation? They don't always balance tires during a rotation. You can also check for play in the carrier bearing.

 

They balanced my tires during the rotation and how would i check the play in the carrier bearing?

 

Get under the truck and grab driveshaft and shake it to see if excessive play is evident. Try pushing it up,sideways etc. Might help locate your problem.

 

...and if it's not the carrier bearing?

I don't want to hijack the thread, but I've experienced the same thing. I've had a new carrier bearing installed, new Firestone tires, new icon shocks and LR upper control arm. One fortune later and still she shakes.

Bent frame maybe?
Dunno...I have no more ideas....

 

Ever take your driveshaft off? Checked to see if balance weight still on driveshaft.
Greased your u-joints? Motor mounts, trans mount rubber or loose bolts on these?

 

i can't say i've checked any of those, but I appreciate the leads...
thanks and sorry op for hijacking.

 

I'm not saying take drive shaft off though. Sometimes people take them off to replace something and don't put them back where they were originally in balance.GL

 

I'm guessing the trans mount should have a rubber bushing in it right? Cause mine doesn't....

 

Take a decent photo of it, and post.

 

I'm with tan4x4 on this. Only know the 95.5 and 96 reg cabs 5 spds. of mine do. On top of crossmember.

 

I guess theres a little bit of a bushing.. but it looks really worn out. maybe thats what I get that shaking. and I also checked the drive shaft and when I push on it it doesn't really move, so I dont think thats the problem. what should the motor mounts look like? since thats the next thing ill check.

 

It's probably not your motor mounts. Should have thick rubber pads(2 mounts) bolted down. Pic didn't work.

 

Guys , the only way to properly check the driveshaft for blown u-joints is by removing it

 

Big tires get cupped, u can't balance that!!