I put a 4" lift kit on my 2000 TJ the other day and used the t-case drop bracket because I don't have a SYE. Well I had a lot of vibration so i loosened the 4 nuts that hold the trans mount and wiggled the t-case and trans around to help seat it better since i didn't loosen them when I put the drop bracket on. Well it seemed to help out a lot but the vibration came back today and I did the same thing as I did last time but no results at all... Any help on what might be happening

gotta do a SYE. Anything more then 2.5" and you need it to cure the problem

I am going to get one in the near future but why did the problem get better the first time and no results the second time?

You can try replacing the u-joints for the new angle and see what you get. U-joints settle in at a certain angle. When you change that angle, you change the needed use of the u-joints. All manufactures don't bring up changing u-joints when changing angles of opperation. Every time I make a change to my suspension system, I change my u-joints to allow a new "seated in" wear time. Just like rebuilding a motor. Gotta change out the old to deal with the new.

Any suggestion on which SYE is the best for the money to go with?

Any suggestion on which SYE is the best for the money to go with?

Just go with a unit that replaces the main shaft for a fixed yoke for a spicer 1310 u-joint. Look for the ones that replace the main shaft for a larger 4340 Chromo set up. You will need to change out the rear shaft for a CV one. Stay away from the hack and tap jobs out there. Not worth it IMOI. I bought mine through Sky jacker(7 years ago) and went with a Tom Woods CV shaft(7 years ago) and zero issues to this day.

How is your pinion angle?

Pinion angle looks good

Pinion angle looks good

4" of lift, no SYE, and pinion angle looks good? Do you have upper adjustable control arms? Have you thought about doing a 1" body and MML to decrease the drive line angle? Sometimes adding washers between the skid plate and frame will help.

I went with the Advance Adapters kit on ours and the Tom Woods CV shaft. So far no problems. You will probably need upper adjustable rear arms if you don't have them already. Then you can pretty much tweek it just like you need to eliminate any vibration.
We have no vibes and we are running a 3.5 RE lift, no skidplate drop, and a 1.25" body lift on 35's

I went with the Advance Adapters kit on ours and the Tom Woods CV shaft. So far no problems. You will probably need upper adjustable rear arms if you don't have them already. Then you can pretty much tweek it just like you need to eliminate any vibration.
We have no vibes and we are running a 3.5 RE lift, no skidplate drop, and a 1.25" body lift on 35's

I did the Advance Adapter SYE / Tom Woods combo as well. There is a step by step write up on the Tom Woods Web site in the DYI link. The Adjustable control arms are a must IMO. Each Jeep is different, when I did the R.E. 3.5 lift to the Little Jeep, I had vibes even with the TC drop. I don't have a BL, so I ended up changing rear axle, adding the SYE, adjustable control arms, etc. No vibes now.... No money in bank either :eek::eek: