2EMES

At Faq questions I've read this:

“Q: Are new driveshafts needed after installing a lift?
A: You really should consider installing a new rear double cardin U-joint style drive shaft if you have lifted your Jeep JK Wrangler 3" or more and have a 2-door. This is needed because the short rear drive shaft of the 2-doors will be at a steep enough angle that the CV boots will wear out prematurely. However, in order to do this, you will need to buy a set of rear adjustable upper control arms so that you can properly set your pinion angle. 4-Door Unlimited models do not have this problem as their rear drive shafts are very long and a lift will not effect the angle of it too much. As far as the front goes, if you have an automatic transmission, you will need to replace the drive shaft with a double cardin U-joint style unit as well as the diameter of aftermarket shafts will be considerably narrower and will not come into contact with the transmission and/or skid plate. Failure to do this will result in the taring of the factory drive shaft boot as it makes contact with the transmission. Manual transmissions will not have this problem and keeping the factory front drive shaft will not be a problem”.

Ok, I understand, then, that JK 2 door will have to replace rear driveshaft always and front driveshaft if they are automatic. And Unlimited will have to replace just front driveshaft and just if they are automatic.

So, my Question is: Is this all related just to a 3” lift?. If so, what happens with 2 door JK and Unlimited Jk in the case of 4” lifts?. What driveshafts replacements must they do?.

And what happens with JKs with 2’5” lifts that give real 3” lift like Teraflex ones?. Are they safe from changing any driveshafts at all?.

I hope someone may help me because, taking the chance that I’ member of Jk-Forum some people in Spain are asking me about all this and I really don’t know what to answer them due to my confusion about it.

joneszj

With 4" of lift you may need driveshafts over time. I have the 4" Superlift on my 2 door and am still running the stock shafts without issue so far. I have had my lift, tires, control arms, etc. on for just about 9,000 miles now and I've wheeled my JK about 7 times since it was put on. I have a 6 speed so I suspect that has something to do with my front driveshaft is ok. A buddy of mine has the OME lift which gave him about 2.5-3" of lift, but he is looking to replace his driveshaft soon because the boot is rubbing on his automatic transmission skid plate. It's sort of a case by case basis as to whether you will need new driveshafts, but with 4" I would say its more probable you will need them than not need them. Especially on a 2 door. On the 4 door you can probably get away with the stock ones for a while. Same for 3" of lift, that would be an even less extreme angle, making less stress on the driveshafts. Hope this clears it up a bit before you...

spinlock

Just to expand on the information in the FAQ:

The size of the lift (ie 2.5") refers to actual lift, since some brands deliver more lift than the nominal amount specified on the lift kit. Some brands like Teraflex publish the effective amounts of lift delivered by each kit.

To complicate matters even more, some lifts kits eliminate rake which requires additional lift in the front, while others do not.

Lifts kits cause two main types of driveline problems:

1. Driveline interference which on the JK occurs on the front DS and occurs first (less lift required) if you flex the suspension.

2. Driveline angle which can cause the joints to bind or fail. If the lift is tall enough you don't need to flex the suspension too far to incur this problem. This happens on both DS and due to the differences in DS length between 2DR and 4DR can happen in different order.

The popular consensus on this issue is to run your stock DS until they fail unless you have obvious interference case or a very high lift. How long they will last depends on your driving habits.

asifasdi

just found this and its exactly what i've been wondering about so heres my question and lets ee if you can help me out..... Im looking at getting the revtek 3 inch coil spring spacer lift which actually lifts the front 3" and the rear 1" i think, so im sure ill be fine just like that......so now im wondering if i can put a REAL coil lift of 1 or 2 inches on top of those spacers without any trouble (lift wise and driveshaft wise)????

asifasdi

by the way i dont do alof of hard core offroading (dont know if that has anything to do with it) but its more of my daily driver with the occasional trip to the farm to do so VERY light offroading.

mkjeep

Most of the coil lifts will give you 3inches, even if they say 2.5, that'll be 6in of lift in the front with spacers, whole lotta stuff to address. If your gonna get new coils just go with a coil lift anyway that will put you at 4 or 5 inches.