Vibrating drive shaft

[fdjizm]

It started after the 4.10 install if I remember correctly, before that no vibes.
Bent axle, maybe? the wheels look dead straight when spinning though.
If I had a bent axle wouldn't I feel/hear something before 90mph?

 

[Napoleon85]

It started after the 4.10 install if I remember correctly, before that no vibes.
Bent axle, maybe? the wheels look dead straight when spinning though.
If I had a bent axle wouldn't I feel/hear something before 90mph?

I would think so - but I'm not sure what else you could even check. Have you had the wheels/tires checked out to make sure everything is good? No slipped belts and the wheels are still true?

 

[fun4me]

I would think so - but I'm not sure what else you could even check. Have you had the wheels/tires checked out to make sure everything is good? No slipped belts and the wheels are still true?

He swapped the fronts to back I think.

 

[fdjizm]

Didn't check the tires at a shop but did swap the fronts to the backs with no change, but I think I will try to get them re-balanced anyway. Did this with the original set of tires also which I changed out a few months ago. I don't know what it could be, when it happens the mirrors blurr whole car vibrates and decelerating is like running over rumble strips till it gets back down to under 90 or so.

 

[Gabe]

Didn't check the tires at a shop but did swap the fronts to the backs with no change, but I think I will try to get them re-balanced anyway. Did this with the original set of tires also which I changed out a few months ago. I don't know what it could be, when it happens the mirrors blurr whole car vibrates and decelerating is like running over rumble strips till it gets back down to under 90 or so.

Have you checked other things that might not normally be related?
Like tierods, balljoints, wheel bearings?

If any of these are worn / loose, a vibration can develop, and it could be a huge safety issue if one of them fails at those speeds ...

If the car was an automatic, the rumble-strip comment would make me think "bad torque converter" ...

 

[fdjizm]

Have you checked other things that might not normally be related?
Like tierods, balljoints, wheel bearings?

If any of these are worn / loose, a vibration can develop, and it could be a huge safety issue if one of them fails at those speeds ...

If the car was an automatic, the rumble-strip comment would make me think "bad torque converter" ...

I had the rear up on jacks spinning it up to test the changes, no tie rods or ball joints are involved. shit is crazy!

 

[Napoleon85]

If it makes you feel any better - I've had similar issues since day 1 with my 2011. Ford has (unsurprisingly) insisted that "it's normal." No amount of balancing, rotating, etc have made it better.

 

[fdjizm]

thats some BS, I was at 130-140 with 3.31's with no vibes.
the 4.10's up the DS speed but maybe it just makes the whole metal body of the car resonate?
If that is the case then it would never be fixed unless I went back to 3.31's while I will never do lol.

 

[BlackDragon]

thats some BS, I was at 130-140 with 3.31's with no vibes.
the 4.10's up the DS speed but maybe it just makes the whole metal body of the car resonate?
If that is the case then it would never be fixed unless I went back to 3.31's while I will never do lol.

Does it make any sort of noise? Humming? Whirring?

Or is it strictly a vibration?

 

[fdjizm]

I would lean more towards strictly vibration which also creates the noise but more a fast vibe that anything else, there is no rythm.
It's just like when a cell phone vibrates (that same speed/tone) but it takes over the whole car.

 

[frank s]

If the vibration first appeared after the 4.10 installation, I'd be trying a re-install with new everything that rubs on anything else. Maybe flawed bearing race, displaced bolt hole, eccentric bearing?

 

[BlackDragon]

I would lean more towards strictly vibration which also creates the noise but more a fast vibe that anything else, there is no rythm.
It's just like when a cell phone vibrates (that same speed/tone) but it takes over the whole car.

Betcha dollar to donuts they installed the pinion incorrectly...

 

[fdjizm]

hmmm like torque wise or something?