Feelin these good vibrations? or bad...
 

So, thanks to everyone who made suggestions for me already on my brake job.

Here's the newest issue, or at least the latest I wish to attack.

My truck is VERY vibration-y at higher speed, 35 on up. I have noticed that 90% of the time its only when I'm on the throttle, unfortunately I need to keep my foot on the gas to keep up my speed.

My theory... bad motor mounts? I'm not really sure where to even look, but its definitely engine vibrations I'm feeling and not road vibrations. PCV valve is new, oxygen sensor is new and I'm throwing no codes...

Any suggestions?

Thanks,
-Justin

Check the motor, trans and driveline. But I would make sure its not axle wrap, these older trucks the springs eventually wear out and you wind up like I have been doing-chasing a vibe for months only to find out its axle wrap due to weak springs.

Get your wheels balanced?

check driveline slop also.

I had extremely old tires on my truck that I replaced in 99 I think, got an extremely bad vibration at low speed that lessened at higher speeds. Turned out I had several busted belts in three of my tires, so that's an option also.

Shouldn't be bad tires, or even unbalanced. As I said, it's only when I'm on the gas. I can coast at 70, more or less vibration free.

How do I check for this 'drivetrain slop'? And what parts of the drive train should I be looking at? And how does one check for axle warp?

Thanks a lot, guys
-Justin