Yeah idk what it is but i just a deep through the floor and steering wheel vibration when i acelerate. It is consistant with rpms so its engine related. It started yesterday after i drag raced my brother with his f150...

Also the pinion seal is shot on the front diff, i want to drop it down and replace the fluid. how hard is it to drop the front diff?

 

You could have spun the harmonic balancer,or worse broke a piston crank or cam

 

and technically there is no way of finding this out right?

 

Does is still do it when you let off the gas? like does it slow it down at all?

 

if i let off at around 60 it does it for a lil then goes away... but i was idling and rev'd it to 2500 and i felt it viberate... and its not a wicked omg vibrate, its just where i can hear a different tone in the engine like its deeper and i feel a slight fast vibration.

 

My engine vibrates more at 2500 rpm and the tone is a bit deeper. It has done it since I got it, it just seems to be rough in that rpm range.

 

could it be worn enigne mounts????

 

Don't these engines have a balance shaft? I had a Honda that lost the "B" belt, balance shaft. Engine ran fine just wasn't as smooth with out it. Found it doing a timing belt replaced it and it was so smoooth when running I tried starting it while running a couple of times. Learned to look at the tach to tell if it was running.