Originally Posted by l3rian

I don't see how lifting the front of a 2 wheel drive truck changes anything with the drive line other than a negligible shift to the center of gravity. Would probably be the equivalent of adding 50lbs of weight in the bed. But glad you fixed it.

Originally Posted by l3rian

I don't see how lifting the front of a 2 wheel drive truck changes anything with the drive line other than a negligible shift to the center of gravity. Would probably be the equivalent of adding 50lbs of weight in the bed. But glad you fixed it.

Originally Posted by tmh23

By lifting the front it changes part of the math that is used ever so slightly.

Originally Posted by UNBROKEN

Not trying to be argumentative here but no, it doesn't. I don't care if the truck is sitting perfectly level on the ground or if it's sitting on its back bumper pointed to the sky, the driveline angles differences are simple math and those differences will be the same no matter what.

Originally Posted by tmh23

I thought I'd add this to a new thread after also posting it to another thread I started:

This is what I did to fix my vibration issue on my 2015 2WD Lariat SuperCab...

So I researched drivelines to get a better understanding of the theory then applied that knowledge to my own ghetto fix and I'm happy to report it fixed the issue. (Watch the homework video links at the end)

I only added a 2.5 level to the front of my 2WD which doesn't have a block in the back. This leveled the truck perfectly but what it also did was change the angle of the front drive shaft so that the working angles of the u joint at the very rear and the u joint that is on the carrier bearing end of the long second driveshaft were now slightly more out and not canceling the vibration. The fix was to move the carrier bearing mount about 2mm up to get the working angles of the two back u joints about a 1/2 degree closer and thus canceling more of the driveline vibration.
Here's where the ghetto comes in... there are clips with the nuts that clip on the frame mount and the carrier bearing mount then tightens to the bottom of the clips those having about 2mm between the frame mount and the actual carrier bearing mount. Crawl under and look at your carrier bearing and you'll see what I mean. I cut the clips but left the rounded position on that stops the nut from turning until it's snug. Now the carrier bearing moves up the 2mm and bolts tight to the frame mount with no clip in between. The guessing part is bolting the carrier bearing bracket centered so the drive lines are lined up as close as possible. I don't think this is too big a deal as the bearing has a bushing. I eyeballed it.

Took her for drive and the vibration is gone. Now all I feel is the AT tires and of course the ****ty rear shocks that always want to hop and shimmy...that's the next thing getting replaced.

Anyway hope this helps and the theory may apply to 4x4's two. Download an inclinometer app for your phone to measure some angles.

Homework!!! Watch these videos a couple times and it all makes perfect sense.

https://www.youtube.com/watch?v=DDmz0tibVGM

https://www.youtube.com/watch?v=f1m-Fh5kiRU

https://www.youtube.com/watch?v=dt69zYAcXME