The Dana 300 Transfer Case. A common, yet small, stout, and easilly modifiable 4 wheel drive transfer case. Early on in my build up of my YJ, I decided to find and rebuild a Dana 300. I talked many people about this, one being John at JB. (My D300 JB internals article can be found here.) Another was Robert at Down East Offroad. After speaking with him, I decided going with the kit Down East offers would be the simplest solution for my setup, and the best way to 'do things right the first time'.

In this article, I will briefly touch on the installation of the kit, and give my thoughts and opinions on the products, and how they all work together with my Jeep and drivetrain to form a complete kit. This article is not meant to be used soley for installation instructions. A complete set of instructions for this kit can be found here: DEOFlipKitInstructions.

My application will be as follows: 1993 Jeep Wrangler YJ, 4.0 HO, 80's Jeep CJ Dana 300, 23 spline AW4 from a '91 XJ, Early Ford Bronco Dana 44 LP front, Early Ford Bronco 9" rear.

The thought and reasoning behind flipping a transfer case is simply to take a transfer case that has the front wheel drive output normally on the passenger side, and flip it 180 degrees so that the front output is now on the drivers side. What drives this can be several things, like engine size/type, exhaust, etc. The main thing that drives this however is the front axle. Many axles have a passenger side drop diff, while other axles have a drivers side drop.

This may sound simple enough, actually doing it is another thing. A transfer case is full of fluid, with seals, shifter assemblies going up into the cab, mounting bolt patterns etc. For this reason, Down East has created a kit that allows you to safely and accurately flip a transfer case and permanently run it upside down.

No more than a week or so after speaking with Robert, my flip kit arrived. The flip kit consists of everything you need to flip the case and run it. This includes a twin stick shifter setup by Advanced Adapters. This is all included into one neat package.

The package arived neatly packed and complete.

Below you can see my transfer case ready for the teardown. This was a model 300 case from an 80's CJ. As you can see, in it's stock form the front output is on the drivers side with the rear output centered, and the shifters going up.

The first order of business is the tear down and cleanup. The same time I was installing the lift kit, I also completely rebuilt the internals of the case. If one was planning on runing a stock case flipped, you wouldnt necessarilly have to completely rebuild the internals.

As per the DEO instructions, after the case is drained, and the stock shifter assembly and front output bearing retainer is removed, you carefully drill and tap the 4 smooth bore holes where the stock shift rails went through the case.

This was simple enough. Make sure to keep that tap level and straight as you cut the threads. After the tap job, clean the threads and install the supplied bras plugs. The DEO instructions say to use teflon tape, but after having some leaking issues, I ended up using a plumbers goop type seal. It's a sort of sealant paste.

After getting all the plugs installed, the DEO has you reinstall the front output bearing retainer. This is aluminum housing that has to be cut down. You will see a picture of the housing later in the article. You can see the top of the bearing retainer in pic 11 below.

In about step 9 of the DEO instructions, you get to start installing the shifter rails and inspection cover bracket. This is after some internal work on the idler gear inside. Below you can see the nifty aluminum spacer bracket for the cover plate. This used to be the bottom of the transfer case, now it will be the top. This aluminum bracket will house the new shifter rail assembly which is also now on the new top of the case.

After getting the aluminum bracket/spacer sealed down, you get to start installing the shifter forks, rails and seals. I somehow managed to break one of my seals while installing it, but luckilly I had another one in my rebuild kit. It didn't fit perfect, but it got the job done. You can see it below in the pic on the right.

After getting the shifter rails installed, you get to put in the detent balls and springs. The detents are medium sized ball bearings around the size of a marble, but solid steel. These are held down by high tension springs. As the shift rail is pushed or pulled, the ball will roll up the notches cut in the rails and lock down on the next notch. Basically puts tension on the shifter to hold it in gear and to keep it from getting knocked out of gear but still allow the case to be shifted without a huge effort.

At this point you are around step 13 in the DEO instructions. After inspecting everything and making sure the case is clean of dirt or metal shavings, you get to install the cover plate and seal it up.

The cover plate is what holds the detent springs down, keeping tension on them.

The next part of the install was probably my favorite. The twin stick shifter assembly. This is a seperate kit all on it's own offered by Advanced Adapters. It's actually an Atlas twin stick kit that Robert from Downeast has adapted to his flip kit for the perfect combo. The shifter kit comes with all the bracketry, linkage, shifters, double shifter boot and knobs.

There is a neatly machined triangle bracket that bolts onto the side of your case that locates the whole shifter assembly.

I went ahead and installed the complete shifter assembly with the shifters to get some pictures. Normally, you would probably want to wait until you get the case mounted up to your transmission before instaling the shifters. This is because typically, you will need to trim a little of your floorboard to clear them, and you wont know where to trim unless you get the case up there, but it wont fit if the shifters are actually mounted.

Here are some pics comparing the flipped 300 case with the stock YJ NP 231 case. Before mating the case to the AW4 transmission, I opted for a clocking ring. This ring was supplied by Novak Conversions. This clocking ring allows you to clock your case up for mor clearance, and also properly spaces out the case from the tranny so as to provide enough clearance for the front output yoke.

Here you can see the case mated up to the tranny. You can also see the straight fitting for the vent breather.

One of the next things I did was trim out the tub tunnel a bit to allow the for the shifters to pass through into the cab. You can also see my 90 degree fitting I swapped in, in place of the straight fitting for clearance.

One additional thing I added was a fluid sight tube. This was done with parts I found at my local Home Depot. I just swapped out the fill plug, and one of the lower plugs with fittings that also have a male hose adapters. I then cut a section of tube and spanned the distance between the two fittings. This allows me to see the level of fluid I have in my case. Very handy.

If you've made it this far, the majority of the hard work is over. From here on out it's just fine tuning, and making things look good.

I was able to install the shifters again, after trimming out my floorboard. You can see the very small section I had to trim out. The stock shifter hole is above the shifters, and the small square section closer to the drivers side is the part I had to trim.

I then got busy making a new cover plate for my tunnel. This also double as a mount for the fancy Advanced Adapters double shifter boot supplied by Down East Offroad.

Once everything was buttoned up and tested, I was able to take my rig out for a spin. The first test drive wen flawlessly and the tranfer case performed exceptionally.

Final thoughts: This article is being written several months after the initial install of the DEO flip kit. So far my impression of the kit is great. The only single issue I've head to deal with is leaking. I've battled small leaks pretty much the entire time, but have managed to get the case pretty much completely sealed now. After experimenting with differnt types of sealants and plugs, it's almost always dry under there. This is pretty amazing if you think about the fact that you are running a transfer case completley upside down from it's original design.

For more information about this kit, and other top quality Offroad products, please visit DownEastOffroad: