XJ going to be the death of me
 

OK Guys im new ive searched everything i can find and i am now under the assumption that it is impossible to get rid of a front driveshaft vibe.

I have a 98 XJ with new short arm 4.5 inch lift 4.88 yukon gears with spartan locker SYE new fully balanced for the 3rd time front and rear DS,

rebuilt steering (all joints and bearings) new motor, rebuilt tranny and transfer case, recentley rebalanced 35 kevlars, and *0 degrees on front and rear DS.

I dont know what im missing but when i pull front DS vibes are gone. My jeep was driveable before i regeared and turned my 80mph vibe into a 60mph vibe. I was fine when it only vibrated at 80 plus because i didnt ever go that fast.

But now that i regeared DS are spinning at higher rpm now so vibe is at lower speed. I am at a loss HELP!!

What do you mean by 0* on driveshaft? The front driveshaft should be pointing a degree or so below the front yoke of the transfer case.

so your driveshaft was vibrating at stock height?


I would try another stock front driveshaft just for piece of mind to rule that out.

From the go pro video i took of it while driving showed unless it was in 4wd there was absolutely no rotation of angle on front axle and from the diagrams i have seen i understood

that running a CV style DS it has to run at 0* and i have the rear set up at 0* also but no vibes there, only when front DS is installed i get vibes.

no was not vibrating at stock this is the 3rd driveshaft by 2 different shops and 3 times balancing and still no different. My driveshaft guys are baffled!

im talking about 0* pinion angle not DS angle

You do have Adj U/LCA's don't you to adj the angle of the drive shaft? I have a 4 1/2" lift like yours with SYE and a new rear DS mine needed rear shims on the differential and adjustable CA's were a must IMHO. I have zero issues with mine at 3" or now at 4 1/2".

does your d30 have a lunchbox locker installed or is it still an "open" ? if you have a lock rite or similar traction devise in the front end you will have vibration that comes in about 60 mph and progressively gets worse with speed. quit re-balancing driveshafts. If you pulled the front shaft and the vibes quit, it is in your front end. Every XJ is different could not cure mine without freewheeling hub conversion.

How much lift?

no locker in front still open just regeared and yes i have adjustable control arms and i shimmed the rear, my angles are perfect and im not about to spend another 1000 dollars on a set of warn lock out conversions i am somehow 13,000 dollars deep in a stupid jeep that was free from father-in-law lol


I guess i am just doomed to take that shaft out until time to wheel. It just sucks because of the time, money and effort my friends and i have put into this thing and i cant drive it on highway without vibes. It isnt a daily driver but it does need to act right.

did you check the front out put shaft on the transfer case? if the front bearing is shot that could send vibrations to the drive line only when the front shaft is installed. It's something to check. It would be a pain to have to put the front shaft in every time you go wheeling.

Yes i did when i installed SYE and yes it is a pain because how it usually goes is i go playing thinking ahh ill just stay outta the hard stuff and then cussing because i am in the deepest hole there and i now have to drag it out with winch or install driveshaft in mud or on off camber hill.