why vibes why!!!!!!

ok searched did almost everything that comes to mind.wheel bearings,tom woods sye and driveshaft,new tires new wheels that have been balanced checked for being true and out of round,angles look good on both driveshafts.the jeep has 6.5 of lift 36 radial tsl's.were 33's then 35's all with the same vibes.the jeep has not been through much since i've lifted so i doubt i've bent an axle tube and when i had them out to put in gears they looked fine.seems like the vibes are coming from under the console to the dash.could it be the tie rod ends?

If it started when you put the lift on, have you checked the axles to make sure they are centered?

If not then a set of adjustable track bars might take care of it. After the adjustment you should be able to tell, but then need to get it aligned if the front was off too.

the lift came with a new adjustable track arm.whats the best way to measure if the axles are centered?would'nt les schwab checked this when i had the alignment done?

oh forgot to say that it is pulling hard to the right after putting on the 36's.but usually when a alignment is needed it pulls but does not vibe.and the vibes dont feel like their coming from the front but hell at this point and money spoent i dont know

Is your front axle a disconnect type? If not, pull the front drive shaft out and test for vibes again. If you still have vibes, pull the rear shaft and drive it using the front only. This should isolate the problem. I'm assuming you've already measured the shaft angles? Often, with a large lift like yours, the front shaft angles are wrong, resulting in vibration with non-disconnect axles.

Another thing, with the Jeep sitting on its tires, measure the distance from the center of each front tire to the spring tower; should be the same on each side. If not, adjust your track bar.

I see your rolling on 36" tsl's , try a stock set of tires and see what happens to your vibes , alot of the vibes might be the style of tire (tread type). I just had some bad vibes alittle while ago , could not find what the problem was , put my stock tires on and the vibes went away. after closer inspection it was one of my rear tires (32" tsl radials) , I had developed a "bubble" under the outer edge of the tread.changed that tire out with the spare and I was good to go . might not be your problem but it's worth a try.

Is it a high frequency vibration or low frequency? They are entirely different types with very different causes. It'd help to know which one you're dealing with before throwing your wallet at the thing.

my axle is non disconnect what are the spec angle that the front is suppose to bein. can i shim it to see if that helps?trailboundxj; i have tried this with stock right after i lifted 33's,354's, and now 36's and to tell you the truth these radials run alot better.jjacobs: it is a high frequency vibe that happens from about 40mph up.

If the front shaft is a double-Cardin type (looks like two u-joints back-to-back at the transfer case), then the drive shaft and the diff pinion axis should be on the same axis.
Again, remove your front shaft and take the Jeep for a spin. This will eliminate the front shaft as the culprit. Adjusting the angle between the shaft and the diff pinion is problematic. Rotating the pinion up to align the shaft results in less caster. You probably can decrease caster to about 4.5-5* positive and still be alright. So put an angle finder on a flat surface on the front of the axle housing (that flat area on each side with the large hole, will work fine) and measure your angle relative to the the ground. If you have recently had an alignment, you should know what your caster is currently set to. Consider the angle you read from the front of the axle as a proxy for the caster. Meaning, if caster is 6*, based on a front end alignment, and the angle off the front reads 10*, then if you adjust your pinion up 3*, you should measure an angle of 13*, implying you lost 3* of caster. The proper way to correct bad pinion angle is to cut the inner "C's" loose from the axle and adjust the pinion angle first. Then rotate the "C's" to get back to ~6* caster. The only shims that are used on XJ's are placed behind the LCA's, causing the bottom of the axle to rotate, adjusting caster; unfortunately, as discussed above, this also changes pinion angle as well.

Does sound like a pinion angle issue to me also. Good advice has been handed to ya. Pull the front shaft out and test drive it.

I have had bad experiences with Les Schwab. Cutting corners and ripping people off is a known way of bis in my town from them. I would not count on what they have done to be good unless you really trust the shop guys.

One thing I have not seen mentioned is also to check your wheel base. Measure from the center of the front hub to the center of the rear hub. Check the other side to make sure they are the same. Adjust as needed vis front control arms.

I'd suggest pulling the rear shaft first and drive it front wheel drive.

well pulled the front shaft and took her up to 65 vibes still there.so tonight i pulled the rear and reinstalled the front.gonna take a drive first thing in the morning to see if thats what it is. how fast can i go with it in 4wd? as the vibes usually dont come on till 35 on up.

As fast as you feel safe. Just remember, braking and handling are a little different with live axle, front drive only. So, in traffic, take it easy and be alert for handling quirks before you slam on the brakes at 60.

took her for a drive this morning with no rear shaft drove like a dream.so i called tom woods and said that more than likely my angles are off and that the pinion and driveline are to be with in two degrees of each other for the bouble cardon shaft.so i'm off to get a angle finder

Told ya so...

I fixed mine by cutting off the perches, cleaned them up with a grinder and set them on axle and used a floor jack to rotate the pinion up till it pointed right at the transfercase and welded the perches back on. No fuss, no muss, no vibes.

ya ya,so now i got to put the driveline back in measure the driveline angle and buy some shims.the pinion is at 20 degrees.which seems really high

so how do you install shims anyways.do tou just loosen the ubolts and slide in the shim and tighten the bolts back up or isit more involved than i think

dude, just replace your motor mounts.

no the motor mounts were replaced a month before i bought it.one less job for me