vibration at 45mph to 55 mph

05 tj 4 inch lift 33" tires 4.0 with a auto
added lift and tires and now i have this vibration at 45 to 55 mph
feels like its in the transmission ?
any thought

drive shaft-pinion angle ?


Did you do a T-Case drop, or install a SYE and adjustable control arms when you installed the lift?

probley need a t-case drop or a sye

Is it on and off throttle? Is it I’m the whole jeep or the steering wheel?

With a 4" suspension lift it most likely is pinion angle as others have stated. 3" is about as far as you can push it without a transfer case drop or a sye. If money is tight then remove the bolts on the transfer case skid plate (good luck by the way) and add in some washers between the frame and skid plate along with longer bolts. This should reduce / eliminate the vibration. You will need to adjust or get a lowering bracket for the t-case shifter. A sye although cost more is a better option and is not difficult to install.

sorry it has a transfer case drop it came in the kit

and the vibration is on the gas only

and not in the steering wheel
more transmission transfer case area

T-case drops are more of a band-aid. First, its unlikely they will exactly dial in the pinion angle. Second, and most importantly, they reduce clearance. We have plenty of pictures of mangled t-case drops in the Pictures forum.

The ultimate solution is a slip yoke eliminator (SYE) with double-cardan rear drive shaft and then adjustable control arms. The adjustable control arms allow the pinion angle to be dialed-in for your specific Jeep.

Check your ujoints in the rear driveshaft also check for a worn tranny mount. I’ve been there and back again with this type of issue

I had this on a jimmy and I found my ujoints were worn. I would inspect for play on the read shaft ujoints and the granny and tcase mounts.

thank you all for the suggestions
i will look into all of them
if i was to go with the sye and suggestions on brand and place to buy ?

Crown Automotive and then Cockcroft in East Providence for the driveshaft.

super short SYE from advanced adapters and a Tom Woods driveshaft.

^^^ X2. That’s what I’m running on my TJ (and adjustable control arms) and have never had any driveline issues with a 4" lift. Check around, there are a lot of sites that offer a package deal on the AA SYE and TW driveshaft combos. Got mine from Savvy offroad several years ago, they had the best combo deal at the time.