Drive shaft vibration?

[rubicon5]

Hey guys, just got the 4.5" RE superfex kit in my 05 ruby. got a cv driveshaft built for it. I have my pinion angle set @ 2 degrees. I still have a slight vibration at highway speeds, was wondering if any one has some insight. Could it be the front DS.  Thanx for the help.

[sgo70]

I got the RE kit as well with the CV, first the obvious, did you get an alignment done. If not be ready for the scariest death wobble when you least expect it, mine started on deerfoot at 110kmh and I had to slow to 20kmh in the left lane before it stopped!
I think longer rear upper control arms are needed to get the angle right, in the meantime after a lot of experimenting I dropped the trnsfer case 1 inch and no vibration at all even up to 140kmh. I know this kind of defeats the lift a bit but it was easy to do until I get the control arms.
Also make sure the lower control arms are extremely tight or they seem to get some play in them causing some clunking when acc/decelerating.
Just something I noticed.

[rubicon5]

Hey thanx for the help, Ya i did the alignment right after the lift, I have 5.2 deg positive caster on the front with max factory toe. With only 2 degrees difference between the rear pinion and drive shaft. it Steers straight, it has a little bump steer but no mad wobbles, yet.

[rubicon5]

I have now changed the rear pinion/driveshaft angle to 0 degrees and still have a vibe, any other areas i could look at?  It only starts after about 90 km/h and pulses on and off. any ideas, thanx

[Da_chopper]

Could it be the front DS.

Take it out, go for a ride and find out...

Is it torque related, i.e. get her up to spead through it into neutral, do the vibs disappear?

[rubicon5]

hey, it is deffinatly more apparant under load, but more at highway speeds than on initial acceleration. So yes it is torque related, any ideas. It has a brand new rear drive shaft built @ DSI. could it be anything other than the rear shaft? I dont have a transfercase lowering kit in it, do i need one? I didnt want to install it, kind of defeats the purpose of the lift and the $650 driveshaft.

[Bnine]

Remove the rear shaft to confirm where the vibe is comming from.

If it still vibes, re install it and run just the rear.

If it still vibes, try a tire swap or rotation to eliminate the rear tires. If the vibe moves from your arse to your steering wheel, tires are the culprit.

If that doesnt do it, check your suspension hardware for torque, and check your axles for proper alignment.

If you still have a vib after all of that, come back let us know.

[rubicon5]

drove it on the front drive shaft, smooth as silk up to governed speed. reinstalled the rear shaft, vibe apparant again. I dont think its angle related, i have changed it about ten times. Any other ideas?
thanx again

[Jonny_XJ]

Get the shaft checked... might not be balanced properly??? Other than that I got no ideas

[Bnine]

Rubi rear axle is just a tiny bit offset to one side, check that.

You dont have a tummy tuck do?

If you are convinced it is angle, a motor mount lift should be enough to correct your vibes.


Last check you an do before you add mml, t-acse drop, or smaller springs is a runout on the rear output balancer.

If you get a runout of 25 thousandths or more, your speedo tone ring is out of alignment.

I dont think this would be your problem, it is usually noticable at lower speeds, and more prenounced then what you are describing, but checking it is free.

Also dont think your DS would be out. DSI does a lot of these and does really good work.

You are probably right that it is angle related. Especially since RE springs measure so high when they are new.

[rubicon5]

hey thanx for all the help guys, One thing i did notice when i removed the rear shaft, was the yoke at the t-case out put shaft doesnt look seated, properly, the nut is tight, but the seal is leaking and it doesnt look square.
When you spin the out put shaft you can see a gap in the seal when it spins only on one side, like its out of round. The nut isnt completely threaded on either. i could see abouth 5 threads on the nut? Probably the problem.  O and no I am still running the stock skid plate.

[Bnine]

hey thanx for all the help guys, One thing i did notice when i removed the rear shaft, was the yoke at the t-case out put shaft doesnt look seated, properly, the nut is tight, but the seal is leaking and it doesnt look square.
When you spin the out put shaft you can see a gap in the seal when it spins only on one side, like its out of round. The nut isnt completely threaded on either. i could see abouth 5 threads on the nut? Probably the problem.  O and no I am still running the stock skid plate.

If that is the case, your vibes should be a lot more pronounced then they are, but it does sound like your problem.


To fix it

Remove the dampener

Remove speedometer tone ring sensor (small torx, top of tailshaft housing)

Remove tailshaft housing (6 x 13mm bolts)

Remove the tone ring. 8 inch 2 jaw puller will work if its jammed up a bit. May have to jar it with a pry bar a few times to get enough slack to fit the puller jaws on

Inspect the tone ring pin seat, and the tone ring pin (new tone ring is 90$ from the dealer, about a 4 day order)

You can make a new, tighter fitting pin by cutting off the end of a drill bit. Test them in the shaft till you get the right size

Red, or green loctite the new pin and install

Coat the base of the output shaft (where the tone ring rides) in red or green loctite

Pre heat (oven or deep fryer) tone ring to about 160F for easy install and to allow loctite to get between ring and shaft

Wipe oil from the ring if pre heated in a deep fryer and quickly slide it into place on the output shaft.

Ensure ring is seated in its pin.

Let the loctite set up for at least an hour, or until you can not wiggle or slide the ring by hand.

Clean up tailshaft housing, mounting surface on the t-case, and re install with a small bead of RTV

Re install speedo sensor

Re install flange 185-250ft lbs (double check that, its from memory)

Top up the t-case fluid.


This is a pretty common problem on rubi's from the factory. The tolerance on the tone ring, and small size of the pin can allow the ring to shift out of its seat when pulling, or re installing a flange.

hope that helps

[rubicon5]

Hey thanx for the help, DSI changed the flange to a cv type when they did the drive shaft. So i dont have the original dampner style anymore. The jeep is there right now hopefully they can sort it out for me. But if not ill rip her apart and take a look.

[rubicon5]

Got the jeep back from DSI, They tried changen pinion angles but still no dice. Vibration still apparant. The t-case out put shaft flange was not seated completly, that is now fixed and the leak is gone.  Tried changen pinion angles again and agian and still nothin. One thing i did notice is that is that the rear axle is slightly over to the right, about 3/4".  Looks like ill be buyin an adjustable rear track-bar.

[Bnine]

Got the jeep back from DSI, They tried changen pinion angles but still no dice. Vibration still apparant. The t-case out put shaft flange was not seated completly, that is now fixed and the leak is gone.  Tried changen pinion angles again and agian and still nothin. One thing i did notice is that is that the rear axle is slightly over to the right, about 3/4".  Looks like ill be buyin an adjustable rear track-bar.

You need to do a run out on that flange to confirm it is truly aligned.

Find someone with a dial indicator and have it done, before you spend moneyon a track bar.