Rubiconpoor,
I have adjustable lowers. I haven't measured the pinion angle.

 

I am going with 35s with a 3" FT Ultimate. If my offroading is minimal, will I still need to change driveshafts?

 

4 door or 2?

 

off roading is not the cause of the drive line demise. It is from the angle that a lift creates. 4 dr's seem to do better. 2 dr owners with 3 inch lifts or larger should really plan on replacing them. Mine gave me very little warning. Just a little sqeak then that great smoking of oil. followed by the sound of A CAT CAUGHT IN THE FAN BELT. all within a 15 mile drive to work.

 

As stated above, it really depends on your JK, 2 or 4 door. On the Unlimited, the driveshaft is longer and the angle is less affected by the lift. If you have a 4 door, I would say wait and see. If you have a 2 door, start planning for that new shaft...

 

I could be wrong...... you may not have to worry about the rear driveshaft on the 4 door, but the front driveshafts are the same (short).

I have a 4 door and the angle of the rear drive shaft looks fine but let me tell you the front, not so good (at the transfer case). I have a 3.25" lift but I think it ended up being closer to 4". At this point the front one is the one I'd concerned with on 2 or 4 door JK's (not ignoring the rear DS on the 2 door).

 

I do have the 2-door Rubicon. So do you suggest that I change the driveshafts right away?

 

Mine lasted about 3000 miles after my lfit was installed

 

I just purchased the rockcrawler 3.5" lift and I plan to get new drive shafts. What are the differences between the 1310 C.V. Heavy Duty shafts and the 1310 Replacement shafts? It looks like the Heavy Duty shafts have new output flange's where the replacement shaft just bolts the the existing flange. Is this correct?