I imagine those 35's on stock gearing would have something to do with it. I'm running the IRO 6.5" LA, and mine rides just fine. I'm on 33's, stock gears (waiting until Christmas), and running the same shocks as you.

 

No sure if this is going to be helpful but, some options to look into/think about.... I'm running the 5.5 IRO LA on 33's

You can try drop the t case down to the lower holes and see if that helps at all....even with the sye.

You can try throw the front driveline on the rear to see if your new rear d line has anything to do with it.

 

yeah the IRO crossmember is made to drop the t-case if you want. If you use the last bolt on the top of the crossmember that gives you a 1" drop so that may help with the vibrations. If not i would plan on regearing, make sure you check your axles (spider gears, axle shafts, unit bearings, or even a bent housing) the axles are on alot of stress with 35's

 

I think I've come to the conclusion that it is my axles, the bearings to be exact. i looked up a couple videos of what bad bearings sound like and its a very similar sound. its really not that big of a deal being I planned on rebuilding my d30 w/ 4.88s and chromoly shafts and truss and building a f8.8 with 4.88s and an ultimate 88 4340 kit with rear truss. im going to let you all know, because I know I'm going to get crap for building a d30, i dont wheel it all to hard. its still my dd (mainly for winter and rainy days) and I probably go to an offroad park 2 times a month. it'll work for what i need. this all should be done within a couple weeks so ill let you know if that was really the problem.

 

You said your caster is at 1.6 and 1.2 degrees positive? Get that fixed first, its free and easy and can cause vibrations, bumpsteer, and a jeep that is hard to keep on the road.

And what was the rc lift that was on it before? same height?

 

I had a 3" short arm with 2" shackles and spacers. I will be fixing the caster on Tuesday. luckily i have another ride till i get this situated.

 

So you had about the same lift height. Just changed the lift components, and think some bearings in your axle just went bad during the lift install?

 

no? from the other lift I felt every bump and only heard the noise from the suspension, which was the reason i upgraded. after upgrading I heard different noises, thinking it was the suspension which was the reason for me making this thread. i hadn't heard what im hearing now. so I asked you guys to see what you thought did a couple things you guys suggested. not all the noise got fixed so i talked to some other people and had them listen and they suggested it might be something in the drivetrain so i googled drivetrain noises and i came to the conclusion its possibly my bearings.

 

oh, so you think the suspension masked up the bearing noise.

 

thats my guess