I have a TJ with the six, auto and D44 combo, with a 2 inch RE Spacer lift, and a 2 inch Performance Accessories body lift with 33 inch BF MTs. After installing the suspension lift I began to experiance vibrations due to the severe angle of the extremely short rear driveshaft. I called Rubicon Express (the people I bought the kit from) and asked their opinion they recommended the Cam Kit from Jeep, it basically raises the angle of your rear differential in order to lessen the operating angle. A number of people expressed an interest in how effective the cam kit is, so here it is. I have driven something like 3500 miles w/ the Cam Kit in.

I purchased my Cam Kit from Rubicon Express for $41.45 including shipping to Cleveland. This seems pretty steep for what amounts to a few bolts, I know of one Jeep which  isn't even using it and the owner adjusted his anyway. It was delivered with practically non existant directions. (I have them somewhere if I can find them I'll scan and post them)  However, thanks to some emails from Don Alderrou, Paul Nasvik, and Tony Sain, I was able to get a clearer understanding of the process. Basically I took both rear tires off, and removed the drivers side upper control arm, I could then (and only after removing the arm) see the punch outs stamped into the control arms at the factory. I happened to have one of those long drill bits for drilling through walls (18"s I think) handy so I used it as a punch, and each of the punch outs on this side came out quickly and relatively easily, at this point I had spent perhaps a half hour, and was feeling pretty good about things. I went over to the passenger side, and this is where it got nasty. For some reason the passenger side was impossible to punch out in a similar manner…no matter how I tried, I ended up using the same drill bit in a drill to sort of chip away at them as best I could, I spent almost three hours on this side!!! I finally gave up after doing a reasonable job… it turns out that this would bug me later. The drivers side would crank all the way back, but the passenger side wouldn't since the knock out wasn't completely cleared out, but I reason that since it is essentially just pushing against the back of this to move the pinion that it just means that it doesn't have to go as far to achieve the same result. So I put in both of the Cam bolts and Cams. I turned them and was surprised to see that I could actually watch the pinion move. So I cranked them both about halfway and tightened them down and went for a drive. There was a definite improvement, but it wasn't great. At this point I'd recommend that you have someone with you, because by the end of the night I was questioning my sanity, and I couldn't tell if I was imagining vibrations or not! Also, try it under hard and soft acceleration. So I ended up after many drives around the block basically cranking them both back all the way which I think has eliminated nearly all the vibrations, I swear I can't tell if the slight vibes I get at around 1000rpm are my 33" BFG MTs or what. It is definitely a HUGE improvement over the way it was. It was vibrating so badly that I couldn't read the screen of my GPS while it sat on my dash, I had to hold it in my hand! Now I can read it no problem. I have noticed that if I really floor it I'll get some vibes still, I am undecided if it is just the engine etc, if the Cam Kit isn't capable of making enough difference, or if the pinion is moving upwards under torque and therefore causing the vibes. I will try to slighty adjust the pinion downwards to see if it could be adjusted to far up, but the current vibrations are pretty slight.

In summary I am glad that RE recommended trying the Cam Kit before the spacers for the Tcase. I think it is an effective and relatively inexpensive way to get the job done. I now have 4 inch of lift and 33 inch tires working very well. My total investment, tires and all is just a little less than what just the RE 4.5 inch lift costs. Granted, I don't have the same flex, but in the Midwest, it doesn't matter as often. Besides, I couldn't have afforded to do it nearly as soon. If you have any questions feel free to email me.