Review & Install Video
A slip yoke eliminator kit is designed to eliminate the slip yoke on the back of the transfer case, giving you a shorter transfer case, and therefore a longer driveshaft. However, this is not something that you can just install on its own. You are going to need that longer driveshaft and it's also going to have to be a CV or constant velocity driveshaft, which will also most likely be a double-cardan driveshaft. You're also going to need an adjustable set of control arms in the back, at least a set of adjustable upper or lower control arms, so that you can roll the pinion angle of that rear axle. So there are a couple of other pieces that go along with this kit, not just the slip yoke eliminator kit. I'm going to talk you through the installation of this kit, which I am going to give a two out of three wrenches. There is no cutting or major modification necessary to get this installed. But you are disassembling your transfer case. Now, transfer cases can seem like a magic black box. If you haven't opened one up before, I promise you, they're simpler than you think they are. So if you're somebody who's handy and you want to attack this in your driveway, you absolutely can. However, if you're not comfortable with that, taking this to a shop is not going to be an issue either.Now, the install is probably going to take you around three hours by the time you get everything apart, back together, and refilled. But we'll talk more about that in a second. So Rugged Ridge has this heavy-duty slip yoke eliminator kit, and then they also have their mega short slip yoke eliminator kit. The mega short is going to give you a little bit of additional driveshaft length, so you can get a little bit of a flatter driveshaft angle if you have a larger lift or you're going with a tummy tuck. Also, those mega shorts will require an electronic speedometer sensor, so that's going to change things up a little bit as well. Now, there are going to be some other slip yoke eliminator kits on the market. Most other companies will also make a standard short and a mega short version, and they are going to be right around the same price. Some are a couple dollars more. Some are a couple dollars less. But they are all going to work for you in shortening up the transfer case. As far as the construction of this kit, you are going to get everything that you need to make things work. You have your slip yoke eliminator itself, which is basically going to be the part that goes around the rear output shaft of your transfer case. You are going to have a new shorter output shaft. This does come with a yoke, which will get you set up for that CV driveshaft. Because this is the standard short, heavy-duty version, you will have a speedometer ring as well. Now, this ring is not going to affect your speedometer as far as calibration. That's the side that actually goes on the sensor. But this is going to allow you to use a factory-style sensor. Like I said before, I am going to give this a two out of three wrenches for the install. However, if you do a little bit of research, you watch a couple videos, do some reading, this is definitely something that you can tackle in your driveway if you choose to. Again, if it is a little bit too much for you, there's no shame in taking your Jeep to a shop to have this done. Again, you can expect to put about three hours into the install, start to finish, because there are going to be a couple of different steps. Now, the first thing to note is that you can do this in your Jeep. I've done it a couple of times, and I've always done it in my Jeep. If you do choose to unbolt the transfer case from the transmission, you can go that route and do it on a bench as well, if you don't feel like laying under the Jeep for that long. Now, the first step in this installation is, of course, removing your rear driveshaft. Then, you're going to go ahead and disassemble the transfer case by removing the rear half of the case. You're going to remove the factory output shaft, as well as the change rod mechanism for the front output shaft. You're going to have to transfer over your gears onto your new output shaft, as well as your speedometer sensor. Something else to consider while you have your transfer case apart, while you're installing this kit, is to go with a wider gear set and a wider chain if you need some additional strength, because you're running really big tires or you just find that you're stretching out a factory-sized transfer case chain. Go ahead and reinstall that with your chain. Use some gasket-making material to reseal your new rear half of your transfer case, and go ahead and fill everything back up with fluid. Then, install your new driveshaft, as well as your new control arms to get all of your angles set up. Now, when you are taking everything apart, this is a good time to do a couple of other things inside the transfer case. If you've been maintaining your case well, all you might need to do is change out the filter for your transfer case fluid. If you have neglected your transfer case a little bit, now is a good time to go and make sure that the bearings are in good shape, and get a transfer case rebuild kit if necessary. You're also going to need to make sure that you have some new fluid for your transfer case handy when you are putting everything back together. This heavy-duty kit is right around $230, whereas the mega short is closer to $400 and has some additional aluminum components. As I said before, there are some other brands of these out there on the market. Most of them are going to be very similar in design and also in function. This is going to have a heavier-duty output shaft than your factory one, and it is going to give you a good bit of strength. Some of the ones that are going to be even more expensive out there might be some of the higher-quality components, giving you just that little bit of additional edge. So if you have around four inches of lift on your Jeep and/or you have some rear driveline vibrations, if you're looking to shorten up the transfer case, get a longer driveshaft, and set your pinion angles properly, this is going to be an affordable option that can be installed in your driveway if you choose to. So that's my review of the Rugged Ridge heavy-duty NP231 slip note eliminator kit, fitting all 1988 to 2006 Wranglers that you can find right here at extremeterrain.com.