Hello all! I've come across a decent deal on a Prorock 44 Unlimited front housing for my Jk. Before I drop the coin, I want to make sure it's what I want. It's set up for a Rubi factory locker, but I want to go with an ARB to match my rear end. How much of a hassle/how reliable will it be, if even possible to avoid the rubi locker and go with an ARB if I go with this front housing? Forgive me for the question if it's elementary, but diffs aren't my specialty to say the least. Thanks for any help in advance!
you can use an ARB locker, ARB RD147, 35 spline shafts and is the ARB locker Dynatrac recommends for use with the PR44. The ARB D157 Rubi locker is not recommended for use in the PR44
The "New Generation" D44 uses thicker R&P gears versus the standard D44, all PR44 are setup to use the thicker R&P
Check the tube wall thickness, the PR44 comes in heavy duty which is a 1/2" thickness and standard 5/16" thickness - all 3" tubes
from Dynatrac:
Dynatrac manufactures the ProRock 44 pumpkins in two different configurations. One is optimized for a standard D44 locking differential and the other for the Jeep JK Rubicon electric locker.
The carrier bearing outside diameter is different between the two axles. Also, the electric locker version has two access ports drilled to allow for wiring harness connections to the locker.
Dynatrac is currently manufacturing a version of the ProRock 44 pumpkin which will accept a standard Dana 44 ARB or Detroit locker. You'll need to drill the ring gear bolt holes in the ARB or Detroit to size in order to match the larger ring gear bolt on a JK gear set. The JK uses a 7/16” ring gear bolt. The bolts are available from Dynatrac if necessary. In addition the locker should be a 3.73 and down model. The JK uses a thick ring gear which will correctly mate to the 3.73 and down lockers.
Will a 35 spline ARB work with the ProRock 44 conventional locker pumpkin?
Yes, in order to take advantage of a 35 spline locker in a ProRock 44 you will need a specific combination of locker parts. The standard 35 spline Dana 44 ARB, part number RD-109, is manufactured to fit 3.92 and up gears. It uses 3.92 and up gears which are manufactured in the thin configuration. The JK gears are thick gears and require a 3.73 and down carrier even though the ratio is numerically larger than 3.73. ARB part number RD-117 is a 3.73 and down carrier which is recommended for use in the ProRock 44. However, the RD-117 is a 30 spline locker. In order to use a 35 spline locker you will need the internal parts of a RD-109 in the body of a RD-117. As an alternative to purchasing two lockers and swapping around parts ARB offers a locker with this conversion already setup from the factory. It is the ARB RD-147 and it will fit our conventional style pumpkin with JK gears and 35 spline shafts.
In addition to this there is also a locker being manufactured by ARB which fits into the JK electric locker PR44 pumpkin. This locker part number is RD157. We do not approve this locker for use with OEM stock or Dynatrac JK 44 pumpkins. It will not setup correctly and we have tested it extensively with our ProRock 44 and also the stock JK 44 pumpkins. In both cases the locker fails to setup correctly and we do not recommend its use. The RD157 is not approved for use in JK 44 pumpkins by Dynatrac.
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As mentioned, if you want/choose to run one, it will be a JK Rubi version of the ARB locker. The axle can come in many conficurations...stock housing, PR44 standard housing, and the unlimited housing with built in castor. This axle would have the stock housing which would have the JK smaller/weaker ARB locker than the PR44 locker. It's still an ARB and still a good locker, but its not the best. Also you will not have the benefit of the built in castor of the unlimited which is nice in a lifted JK for handling and drive line vibes.
Dynatrac does not recommend the Rubi version of the ARB locker be used in the PR44, see above