I would like to install lockers on my 94 ZJ.


After doing some research I learned that spline count was critical to choosing the correct locker. So I needed to know how to determine that value for a given differential without actually counting them and came to this forum after searching the web. Seems one must know which differential one has, D44a in my case, and when it was manufactured, 1994, to do that. I also know that the axle/diff I have came from a ZJ as I replaced the OEM axle on my ZJ with it. However, I am still left with two choices, either a 27 or 30 spline count from the information I've learned in this forum. Does anyone have any definitive idea other than doing an actual count to verify which I have?


Another issue has also raised its ugly head in my research. A post I read in response to the same question of determining spline count, asked by many others, suggested that a locker could not be used with the D44a differential. I also recall an article that said only one manufacturer built a locker that could be used. What are the reasons for this restriction?


Third, I welcome comments on Air v Electric.


Finally, I have researched a number of manufacturers that build a D44 locker. Three, Aussie, ARB, and Detroit Eaton are suppliers that have good reputations. Any comments or thoughts as to which is better?

 

All three lockers you listed are good brands, but all three are different types. The Aussie locker is what is called a "lunchbox locker", it replaces the spider gears with a ratcheting type of mechanism. It's the least expensive and easiest to install. The ARB is a selectable locker that requires an air pump and some plumbing in order to make it work. They are expensive and can fail if the axle slightly bends like the aluminum housing of the 44a can. The Detroit is a traditional locker the locks under a load. The whole carrier is replaced, so it is difficult got a novice to install correctly. It's also very expensive.

 

The dana 44a did not come out tell 96,So unless someones swapped axles in your zj you have a dana 35 in it.The dana 44a is not a normal dana 44 its more of a dana 44hd which is bigger then a normal dana 44.Being its bigger and not many things used the 44hd the market for lockers is small for that reason.Only way to know what spline count you have is pull a axle and count them.

 

I might suggest you start with a build sheet and see where that takes you. Things get changed but it will tell you what came in it from the factory.

 

Sorry guys, but if you read his original post carefully, you'll see he replaced his rear axle already with a D44a. All he wants to know is his axle spline count without pulling it apart. I think he's got to pull an axle to know for sure.

 

Thanks for the replies. Seems there's nothing to do but pull an axle, sigh

 

It shouldn't be that big a deal because I don't THINK the D44a is a c-clip type diff, so you just pull the 4 seal bolts and it slides out.

 

going by this http://d44tech.com/Dana_44A.html it has c clips.

 

Okay, I'll remember that.

 

Great info regarding this differential Andrew, Thanks.


Just to ease any concerns, I do have the Nth Degree TJ/LJ/ZJ Front Dana 30 Slider and Nth Degree TJ/LJ Rear Dana 44 Slider (yes, it fits nicely) to deal with any rocks as mentioned in the referenced article.


Again, thanks to all for an informative discussion!

 

If you need help finding parts i know some sites,From quarter panel armor to light bar mounts.

 

I learned that my D30 is a 27 spline and I have it in my mind the D44Aa (aluminum) is a 30 spline, although I can't find any corroboration of that.

I also learned that the reason having a D44a precluded doing a LSD re-gear or installing a locker, exception being a "lunchbox," was the shape of the pumpkin. A D44a pumpkin is wider than, side-to-side, and not as tall as, a cast iron or steel D44 pumpkin.

My project involved having: an Eaton Dana 30 27 Spline 3.73 UpE-Locker (ETN 19818-010) ; Nitro Gear and Axle's 4340 Chromoly Dana 30 Front Axle Kit (NA-AXN24110) and 4340 Chromoly D44HD Jeep ZJ C/Clip Rear Axle Shafts (AXD74871-1X, AXD74871-2X); and an ARB Differential Breather kit installed.

So now its on to the next project, that is if I don't break anything in the meantime. I have in mind a Rear axle Truss (TnT) or Sports Cage (Rock Hard 4x4). Too late for body armor, already have significant dents and scratches - ouch!

Thanks to everyone for all the great info and discussion