Yep, I'm going through adding adj upper control arms in the rear for this reason (i.e. to adjust pinion angle). I installed (for free) a driveline vibration along with my JE Reel 1310 rear shaft this past weekend Although I really won't be laughing when I have to buy the arms... Oh well, 1 set of adj arms down, 3 to go Slowly but surely replacing my Skyjacker lift with FT!

 

OK.....2000 miles later and I just bought new driveshafts. If you have a lift on your JK I guess you can plan on the factory shafts failing!!

 

So did yours fail or did you just get the new shafts to prevent problems?
I haven't replaced mine yet and haven't had any issues,,,,,yet.

 

Daaaaaaaaaaaaamn!! After I read this thread... Im like so what in the hell do I have to do?! I got a 2-door JK with a 4" superlift (bilstein shocks). I broke the rear driveshaft and fortunately the warranty covered it. Now, I'm looking for a driveshaft that covers all the needs right? But, do I have to change the arms and everything that ya'll are sayin? I thought that I just have to change the driveshaft and everything was gonna be alrite!!
In summary, I'd like to know what can I do. You know this OEM d/s is gonna get broken again and this time the lifetime warranty is gonna say and I'll be driving on my BMdouble-feet!!
So... I'll appreaciate advices-comments!! Thanx!!

 

You most likely will need to plan on installing adjustable upper control arms. With that size lift, your pinion angle is probably going to be off enough to cause a vibration that will be magnified in a double cardin u-joint style driveshaft - at least this seems to be the trend. I'm sure it's not in all cases... But if you measured it, you would probably find that you would do yourself a favor by installing them even with the OEM driveshaft as the pinion angle is most likely off here as well. The CV-style joints are a little more forgiving (i.e. smoother riding), but just not as sturdy as U-joints...especially if you're doing much wheeling. Just my 2 cents.

 

Alright! And which control arms do you recomend?... Do the control arms change the angle of the drivesahft? I mean, does the axle move in a way that can help the angle of the pinion?...

 

I chose Full Traction...but there are lots of different vendors that make high quality adjustable arms. Either the upper or lower arms will allow the axle to roll forward/backward thus correcting the pinion angle. I got uppers simply because I needed to roll the axle back towards the rear (i.e. pinion moves up). This could have been done using lower arms, but doing so would have caused the wheels to move towards the front of the Jeep and not remain as centered in the wheel well (with a higher potential for rubbing during flex). Does this make sense?

 

Ok Im going to put my thoughts on the issue because Ive been doing some thinking. I have my 2 dorr lifted 4.5 inches suspension and adjust. arms all around. now its a brand new jeep and I ve been testing it on road and offroad with stock driveshafts I have a je reel on the shelf but why fix something that isnt broke. heres what Id like to get you all do "opionate" on here goes. If the stock show no vibrations and the angle is adjusted to where the shaft of the cv is coming out of the center of the boot pretty close to it its working. now I can use them until they give an issue it could be a long time then I just go put on my spare je reels. I just cant imagin e taking a brand new drive shaft that works with no vibes (yet) and putting on a ujoint style. I understand the u joint will hold up longer. heres the pull. would you: (A.) LEAVE STOCK CV FOR NOW AS SEE WHAT HAPPENS. (B.) PUT ON JE REEL SHAFT ASAP. (C.) CONVERT TO AN AMPHIBOUS HOVERCRAFT HAHA but seriously...any thoughts... Im going to keep an eye one the boot I dont beat my toys I do some hardcore but I take it slow and check all the way after extreme portions on trails.