Vibes driving me crazy

Still getting vibes after lift. 2.5" front 1.5" rear aal, bilsteins all around. I put in the ecgs bushing and changed the pass CV axle. Also put in a new carrier bearing in the rear. Any suggestions? It's not the tires and wheels either. I would really like to figure this out but am tired of spending money. I did lifted the front a week before I did the rear but didn't notice the vibe until I did the rear. It just sounds like it is coming from the front

 

Diff drop??

 

I have the same issue with a four inch lift, and like you, replaced the carrier bearing. I had a CB drop, which I eliminated. I eliminated the CB drop because it puts the CB at an angle. The CB sees lots of revolutions, and dropping it puts it at an angle. Keeping the stock height, even though it puts more of an angle at the diff and after the CB, seems to work better. To me, the drop is bad news. It actually helped removing the CB drop.

I made one giant mistake - I did not put the driveshaft back together mated up. I marked them and forgot to line them up. I plan to have the whole thing re-balanced to see if it'll help.

A lifted rear end with a sharp drive line angle form the CB to rear diff is known to cause issues.

Hope my experience help you some.

 

Diff drop is definitely a good idea, regardless if you have vibes. If you remove the rear driveline and drive around it "front wheel drive" and the vibes go away, you've just isolated the vibes to the rear.

Have you considered angled shims for the rear axle? A lot of people run a CB drop and don't have issues. You shouldn't need much, maybe 1/2".

 

Diff drop is on its way. I thought about shims for the rear but I haven't been really messing with anything back there because the vibe seems to be coming from the front. But I could be wrong, noises can be deceiving.

 

For you and the OP...
i cant confirm but some say you have to have it indexed, ie same orientation as when you took off the driveline. One way to check if the vibe is from the rear is to remove the rear driveline completely and drive with 4x4 engaged, if the vibe goes away you know it was in the rear, could be an indexing problem, worn ujoints/cardan joint and or carrier bearing. Also make sure the carrier bearing is inline with the axle front to back. there is some play you can get from from side to side which also could affect it. I would think adding bushing or washers to drop the carrier bearing would lessen the angle on the axle and should theoretically reduce tension...just my .02cts....

 

Video on how to check the driveshaft phasing. If it's out of whack it causes vibes. Return the diff drop that wont do anything and can even make the situation worse.
https://youtu.be/dt69zYAcXME
Pick up one of these to check the angles, super useful for a ton of other stuff.

$31 Johnson Level & Tool 1886-0000 Magnetic Digital Angle Locator w/ 2 Buttons, Orange, 1 Locator

https://www.amazon.com/Johnson-Leve...ocphy=9021648&hvtargid=pla-493230952983&psc=1

Also check for bad u joints, pump some grease in them while you are at.

 

Adding CB drop does lessen the angle at the diff and just south of the cardan joint. My issue with dropping the CB is, doing so will put the driveshaft at an angle and carrier bearings are not meant to be run at an angle. Another way to say it is, the carrier bearing will be at angle to the driveline if it's dropped. An angled carrier bearing will definitely wear sooner than later.

 

If I pull the rear drive line is it a good idea to run at around 60mph with just front wd?

 

4wd high range can be run at any speed, so yeah, you should be fine. just make sure you don't have any brackets flopping around.

Oh, and the diff drop is generally good for 2.5"+ lift anyway. It's more about helping your CV angles, not for reducing vibes. Some will disagree because it doesn't lower the diff "that much" however it does lower the diff some, which IMO is better than none, making your CV angles better than before.