I just purchased the 3.5 inch series II lift from Rough Country. Supposedly there will be rear drive-shaft issues once I run above a 3 inch lift. If I replace the drive-shaft with a double Cardan with U-joints, then I must change the angle of my rear axle to align with the drive-shaft.

Why don't I just change the angle of my rear-axle and keep the drive-shaft I have now? The whole issue with replacing it is because the CV joint operates at too large an angle once the vehicle is lifted...Couldn't I just reduce that angle by using adjustable upper control arms on the rear axle (would I need to re-seat the springs???)?

It just seems to be a waste of time to change to a Cardan drive-shaft which requires me to change that angle, all because the angle was too great to begin with. Seems like I should just adjust the angle and be done with it.

Has anyone done this, or is there something about the original CV joint that will prevent me from doing this?

Thanks for your help...I am obviously a newbie to all of this, but I can't wait to start wrenching!!!!

Mike

 

is it safe to assume you have a 2-door? setting your pinion angle will only address the severe angle of the cv joint on your pinion - NOT the output shaft on the t-case. yes, this will help reduce the angle there but, it will not eliminate the problem and it will still fail sooner than later. having said that, you should be able to run what you have until it does fail and just replace it once it does.

 

Yes, I do have a 2door and it is a 6 speed. Your reply makes sense in theory, but unlike the rear axle yoke (I think that is the proper term...) the yoke coming out of the transfer case is not parallel with the surface of the road. Due to this fact the angle coming from the transfer case is smaller, thus it looks that even with a lift it should be okay...

So...Has anyone tried this? I am going to try to measure these angles both before and after lift. I believe the angle coming from the transfer case will ultimately (after lift) be about the same as the stock angle at the rear axle...If that is the case, my plan should work right?

Anyone who has experience with this, please share your thoughts!!!

If I do decide to change the angle of the rear axle, how does that work with the seating of the rear springs? Does it affect the shocks at all?

I know I have lots of questions...I just know that just about everyone on here has much more knowledge about these things than I do!!!

 

This is no theory, do a search and you will find plenty of people who've attempted to do this and eventually found out what happens. But hey, you seem to have it all figured out so why not just believe whatever it is you want to believe and just do it.

 

If you change the angle now, it will help. But it will blow out.

I've owned two- two door JK's, both with 3" of lift, both with adjustable control arms, both blew the rear driveshaft out.

 

If I thought I had it all figured out, I guess I wouldn't be asking for advice would I?

 

Thanks for the info...Guess I will go ahead and switch drive-shafts now...Things like that seem to happen at the most inopportune times.

 

My 4 dr has the same issue. Will be replacing very soon. Waiting would be gambling.

 

Eipi -

I just put a 3.5 inch AEV lift on 3 weeks ago and my drive shaft went after 5 days. The angle was so severe that is was bumping. Hope this helps....

 

Wow...5 days? That's nuts! I am in the process of finding a replacement. Thanks for the information!

Mike