Driveline Vibe Diagnosis Help

I would remove the carrier bearing drop and see if you can get the front and rear to be within 1 degree of each other and the middle joint to be under 1 degree. I think my front was about 3 with the middle being .6 or .8 and the rear being just over a degree bigger than the front was like 4.2 or 4.4 under acceleration the rear angle decreases. No vibes on accel or decel

 

interesting, you don't think the carrier bearing drop kit isn't helping me?

 

so i just removed my carrier bearing drop kit. .. my new numbers are... trans shaft 4.4, 1st shaft 5.8, 2nd shaft 7.8, rear end still 8.2.

so i'll run the numbers on spicer.. BRB..

 

I would start adding small washers to adjust the carrier bearing down. You will probably want some movement there. You can also unbolt and flip the carrier bearing and it will change the drop height. If you can get the center bearing to 1 degree or less you will probably be really close. I would also drive the truck after each change. It’s worth it to note the changes and where it feels better and worse.

 

can you advise direction on flipping the CB, i'll search for it, but im guessing its straight forward as it sounds..

 

Unbolt, spin 180 degrees and bolt back up. The carrier bearing mounting tabs aren’t on center so it can also provide extra drop or lift depending upon which way it currently is.

 

interesting.. now i'll go try that.. i'll be back with some new numbers again.. lol

 

I think on my truck it was about a degree change.

 

i reset my angle meter, so thats why the output shaft, and rear end numbers changed.. either way the operating angles are changing.. but in the right or wrong directions?

 

I think you're going in the right direction. What I think you want is operating angles 2 and 3 to be as close to each other as possible. Here's a video that really helped me understand
https://shiftsst.com/blog/post/driveline-angles.html

 

food for thought.

 

Would honestly try a 2 degree shim with carrier bearing drop in. I went with wfoconcept shims with new center pins. Solved my low speed vibrations after my deaver expedition leafs. I didn’t notice any significant change when I rotated the carrier bearing

 

so you think this is what i should be installing? knock down that 8.2 something closer to the 4.2 output shaft?

 

Are these your most current numbers?

 

yes..

 

It would help to see the driveline, but the easiest route to go is get the center angle at the carrier bearing close to 1degree, they are not designed to be zero. The carrier bearing drop looks to have gotten you pretty close. And a 2 degree shim should get you within the ball park of a degree difference for operating angles 1 and 3.

 

For what it’s worth, I had exactly what you described after I installed a similar lift a few months ago. Thought it was the drive line but couldn’t solve it.

However, I didn’t use a torque wrench on the lugs. Went back and torqued the lugs properly and all vibrations are gone.

 

i do have a tourqe wrench and i do use it often.. i have operating angle issue.. i think im going to order angle shims tonight.. and a new set of center bolts.

 

Something like this should work. I personally went steel and painted it some some zinc primer and black paint. You don’t have to replace the center pin but I would recommend it, double check the existing size before ordering.

 

Leave one wheel on and drop the axle on the other side, 2 C-clamps to hold the leaf pack together and it’s a pretty quick 2-3 minute swap.you’ll spend more time getting the center pin to line back up in the hole on the axle then anything.