Jana K4

JANA k4™ kit Installs the new Stronger Dana JK44 gears into your old standard d44 making them approximately 44% stronger. This hybrid kit comes complete with all adapter bearings, standard bearings, seals, shims, spacers & instructions, to install the newer style JK44 gear set with a Dana 44 carrier 3.73 & lower (or Posi) into the old standard pinion D44 housings. Gear ratios available: 4.11, 4.56, 4.88, 5.13, & 5.38. Jana 3/8" thick cover girdles also available. If you can install ring & pinions & use a die grinder you can install this strength improving kit. If you are running alloy axles then you need this kit as the Ring & Pinion is now the weak link in your drive-train. This kit allows you to upgrade to 31, 32, 33 or 35 spline axles without having the limited strength of the 44 ring and pinion, yet not lose any ground clearance. How it’s done:

1st. We have to get the larger gear in the housing. Since the Jk44 ring gear is approximately 1/2" larger in diameter the than the D44 ring gear, there needs to be 1/4" clearance around the D44 ring gear in the housing to clear it. Most 44 housings are cast with approximately 3/16" clearance, so only very small amount of grinding in a few spots is necessary.

2nd. We have to get the pinion in and it needs different bearings to accommodate the larger shaft size. Luckily, there is room to get the parts in with the proper spacers, shims and adapter rings.

3rd. The larger and thicker ring gear needs a carrier that moves the ring gear away from the pinion. To do this, a D44 3.73 & lower numerically carrier is used. So even though you are installing 4.11 series & up numerically you need the 3.73 & down numerically carrier to get the ring gear flange farther away from the pinion center line. The carrier is also drilled to accept the larger JK44 ring gear bolts.

Cost Benefit Analysis

1st the Benefits:

Your Ring & Pinion is 44% stronger! with no loss of ground clearance. Dana rates the 44 @ 3460 Ft-lbs maximum momentary output torque. Although I could not get exact figures from Dana the pictures show that the JK44 gears are beefier than a D50 set and since Dana rates the 50 @ 5000 Ft-lbs maximum momentary output torque. You’re going to get more than 1500 ft-lb increase in capacity. Also if you have alloy axles, then your current week link is the most difficult and expensive part to repair i.e., the ring & pinion. Let’s not have that.

2nd the Cost:

The net cost is only $150 bucks, and a few more minutes labor. If you compare the cost of the new school gears to the old school gears they are within a few bucks of each other. Now if you’re going to do this right then you need a new installation and bearing kit as well, this is going to set you back about $150. You’re going to buy a posi/ locker anyway so that doesn't even figure in.

We of course can sell you everything necessary for this hybrid conversion. But there are also plenty of wrecking yard finds for the cost conscious. The question I get the most is: "What carrier do I need to find to work with this Hybrid kit?" The answer is any 44 carrier/posi/locker that is made for 3.73 & down numerically gears. (Sometimes referred to as a High speed carrier). The next question I get is "I already have a D44 3.92 & up carrier/posi/locker, can it be made to fit?" Unfortunately the answer is typically no. However If you have a ARB air locker we can supply you with a new case 1/2 and air cap assembly so you can put your internals in it. There are also the new Jeep Rubicon & JK OEM factory air lockers that will fit.

Kit Price includes: 1310 pinion yoke, pinion set up bearing and master install kit less carrier bearings (reuse your carrier bearings if good)


Kit Price $390
Add Carrier bearings stock carrier $65
Add Carrier bearings aftermarket carrier $80
K4 1350 yoke upgrade $65
3 quarts Severe Gear 250 $72