Drivline vibration
- Thread starter Mike78133
- Start date
You NEED to install adjustable rear upper control arms to set your pinion angle - it is required and there is no other way to address this. No changes to your coils or shocks is needed.
I have the same problem with the front drive shaft! I have a 4 inch superlift and the angle caused my front drive shaft cv joint to start going bad
If that is true, the solution is NOT the same. Up front, you NEED to give caster angle priority and that will prevent you from setting your pinion in line with the drive shaft as you would need to do in the rear. If your caster is already set at +4°, your drive shaft is in need of being balanced.
Mike78133
New member
Thanks for fast feed back. Time to order parts. Just have to avoid that 20 - 30 mph range until they get here.
Mike78133
New member
Well, I got tired of waiting and called Morris 4X4. Control arms weren't going to ship for 2 more weeks. Cancelled order and placed with RoughCountry. Should be here by Friday!! And I saved money. I don't know where y'all buy parts, but never again from M 4X4 for me. They offered me a 10% discount if I would wait another week. Give me a break. Paid for 2nd day air and still saved over 10%.
Atch
New member
Well, I got tired of waiting and called Morris 4X4. Control arms weren't going to ship for 2 more weeks. Cancelled order and placed with RoughCountry. Should be here by Friday!! And I saved money. I don't know where y'all buy parts, but never again from M 4X4 for me. They offered me a 10% discount if I would wait another week. Give me a break. Paid for 2nd day air and still saved over 10%.
Northridge4x4.com is very fast and preferred by a lot of folks
Is this on 2-door?
I bought a JK 2-Door 2008 about a year ago that came with:
* A SkyJacker (SkyCrapper) budget lift (4");
* Stock front-drive shaft.
* Rubicon Express 1310 rear driveshaft (double cardan).
The issues I have (had) been dealing with are:
* Wobble shimmy during acceleration, hitting road ruts or potholes.
* Vibrations accelerating from 20km/h to 40km/h and from 60km/h to 80km/h, which got worse and worse over time.
* Over time, clanking metal on metal sounds coming from under the shifter when travelling at highway speeds and letting off on gas.
Most of the wobble shimmy issues were fixed by replacing my BFG KM2s, which were mostly warn and unbalanced. I also replaced the bushings in the Skycrapper lower control arms that came with the Jeep *twice* within the period of time that I have owned it. The second time, the retailer where I bought the replacement bushings from replaced them under warranty since it had been less than six months since they were replaced. They do not last very long and they were leaving a lot of room for play.
Even after replacing my BFG KM2s and getting my tires properly balanced, I still had the metal clanking and vibrations during acceleration. Things continued to get worse and worse to the point where my spouse was starting to notice the noises.
Finally bit the bullet and replaced all the control arms (upper and lower) in both the front and back with Tera-Flex adjustable arms. In doing so, we have fixed the pinion angle in the rear to the point where there is almost 0 degrees (eye) on the drive shaft / pinion angle. Since doing so the metal on metal clanking sounds disappeared and *almost* all of the vibrations have disappeared except one, which has since been exasperated. This new vibration, which may have been masked by the other vibrations experienced while driving, happens when going around 100km/h or greater, it is constant but comes with a deeper vibration that comes in waves, like it peaks then drops then there is a pause and then it peaks again and the so on. Not sure where this is coming from, it may be the drive shaft is unbalanced, or one of the U-joints in the double cardan side is gone as well or maybe the replaced one went again... Kind of at a loss as to what it could be at this point.
Anyways, in regards to your concern with having coil springs or the the bump stops, if you rotate your axle, you may notice that the Skyjacker blocks that extend the plate for the bump stops may now be slamming against the bolt that attaches to the rear track bar. This is my current dilemma, and the plan is to grind the plate that is attached to the axle off, and weld on an after-market plate to put the geometry back. Right now, every big bump I hit in the road is slamming the bolt threads of my stock track bar into the Skyjacker block instead of the bump stopper. And I haven't really flexed it yet to see if the springs are hitting anything, if so, it means the plate for those needs to be ground off as well.
The other option is I add some degrees back in between the drive shaft and the pinion...
Anyways, sorry I kind of hijacked this thread but I just noticed you might have some of the same lift parts as me... At this point my rig is kind of a Frankenstein-lift with all of the brands of parts I have been throwing at it to resolve my issues. And if anyone has any clue what could be the vibration issue I get at speeds above 100km/hr, it'd be great or at least how to narrow it down.
Mike78133
New member
xed,
I bought my 07 with the "dealer installed" Skyjacker lift. Definitely a budget kit, as all drivelines and control arms were still factory. The boot on rear driveline split after 38,000 miles and then came that metal/metal knocking sound. Replaced with J. E. Reel double carden shaft and replaced rear upper control arms to align pinion. sway bar bracket is now a little close to left rear shock but so far hasn't contacted it. No issues so far with front drive line. I limped along for a few weeks after installing rear drive line before correcting pinion angle so I hope I didn't cause any damage to u-joints. Good luck finding your remaining vibration issue. I would 1st check u-joints.
I bought my 07 with the "dealer installed" Skyjacker lift. Definitely a budget kit, as all drivelines and control arms were still factory. The boot on rear driveline split after 38,000 miles and then came that metal/metal knocking sound. Replaced with J. E. Reel double carden shaft and replaced rear upper control arms to align pinion. sway bar bracket is now a little close to left rear shock but so far hasn't contacted it. No issues so far with front drive line. I limped along for a few weeks after installing rear drive line before correcting pinion angle so I hope I didn't cause any damage to u-joints. Good luck finding your remaining vibration issue. I would 1st check u-joints.