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Lock Right Differentials
For the Dodge Ram
245 Fishcer Ave,
Bldg B-4
Costa Mesa, CA 92626

(714) 545-7400

Reider Racing
12531 Universal Drive
Taylor, MI 48180

(800) 375-1330

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Traction aid installation and use - comments from owners
LockRight  TruTrack ARB Air Locker

LockRight Basics:

The standard "open" differential always divides torque equally between the wheels. If one wheel slips and starts spinning with only a small amount of torque applied, the other wheel also receives only this same small amount - and your vehicle stops.

For limited off-road use or moderate snow, the most bang-for-the-buck is a factory $220 limited slip option. The chief problems with the LS differential are clutch wear after 50k miles and the fact that the differential does slip, especially when one wheel has little traction.

A locking differential such as the Lock-Right automatically delivers up to 100% of the available engine torque to either wheel - so that the one with the most traction will help keep you moving. A locker will cost about twice as much as the factory LS differential and it will be much less civilized on paved roads.

An air locker, costing cost $1000+ with installation, offers the best of both worlds. It can be swiched between full open for highway use and fully locked when traction is needed.

Just remember that no matter what you put in the differential case, if you have all possible wheels spinning, you are stuck, and that the more wheels you are forcing to spin, the more stuck you are...

Lock Right Operation

The Lock-Right consists of two bi-directional over-running dog (toothed) clutches. Each one has a driving member (the driver) and a driven member (the coupler, or in some models the existing side gear). Both clutches are rotated by the pinion shaft(s) (or the spider). Each driver has special recesses cut in one face that receive the shaft(s), and radial teeth cut in the opposite face. Each driver mates with its coupler to form a fully-locking combination , and the coupler also receives the axle shaft to drive the wheels. A full-locking differential will get a vehicle into and out of many places that would have been difficult or impossible to reach without it.

When your vehicle is moving straight ahead, both wheels are rotating at the same speed and both clutches are fully engaged (locked). When your vehicle begins to turn, the outside wheel starts to rotate faster than the inside wheel. The two clutches sense this difference in speed and allow the coupler (or side gear) of the outside clutch to unlock so that the wheel can rotate freely. It thus is "ground driven" faster as the vehicle is turning; power continues to be applied to the slower (inside) wheel. As the vehicle straightens out, the wheels again rotate at the same speed, and the outside clutch re-engages. This differentiating action occurs automatically for right and left turns and in both the forward and reverse directions.


Its design is simple and rugged. It is an automatic 100% full locking differential that is "allegros" - no belleville washers, clutch packs or cone clutches to break or wear out. The Lock-Right simply replaces many of the parts inside the standard differential case.

It uses your own stock differential case, bearings, pinion shaft(s) or spider thrust washers (and also the side gears in some models) rather than parts that are all specially made and therefore more expensive.

It uses stainless steel springs and discs for excellent resistance to high temperatures and fatigue. The drivers and couplers are made from high-carbon steel and are heat-treated for toughness and durability. It uses standard gear oil rather than a special limited-slip differential lubricant. It can be easily installed by anyone familiar with general automotive work. With care, it can be installed without altering the drive pinion and ring gear settings - they do not need to be "setup" again. It minimizes the tire wear that is associated with some other lockers and also with limited-slip clutch pack differentials by allowing free rotation of the outside wheel during a turn. It can increase gas mileage off-road in either a 4x4 or 4x2 because of more efficiency due to increased traction, especially in sand. It has been operated extensively off-road in some of the most rugged trucks in the world - and has been triple-checked for proper materials and design.


It is suggested that your first installation be done in the rear axle. The weight of the engine over the front axle is reduced by weight transfer to the rear as your vehicle climbs a hill, meaning that more and more weight is being applied to the rear axle, where the locker is located, as more traction is needed. Remember that the ultimate responsibility for the success of your installation and the subsequent proper operation of your vehicle rest with you, the vehicle owner.

The following steps are only a general guide to preliminary operations used for preparing your vehicle for Lock-Right installation. For detailed info, refer to your shop manual. In general the steps include:

Continue with the install by:

g) Determination of Axle Type
h)Removal of the Differential Case and Ring Gear Assembly From the Vehicle (thick ring gear)
i) Disassembly of the Differential Case with thin ring gear, and C-Clips; also with thick ring gear (case removed from vehicle)
j) Inspection of the parts & Preparing the parts
k) Assembly of the parts into the differential case
l) Assembly inspection & Vehicle Final Assembly & Testing

Subject:      RTML: Traction aids
Date:          Sat, 17 May 1997 17:08:42 -0400 (EDT)

   I have not been too happy with most limited slip units.  They seem to "lock up" just enough to cause chattering and tire wear, but not enough to help when you really need them.  If you can take some extra tire wear, and snapping and banging on corners if you abruptly apply/release power, the most famous, strongest, and most positive (while being user-friendly) "limited slip" carrier may be for you.  It is the No-Spin or Detroit Locker, from Tractech.  Since our Rams have long wheelbases, the positive locking and unlocking actions do not affect handling and steering nearly as much as on Jeeps and other short vehicles.  The Detroit Lockers are available for the 60 and 70 series.  They also have one for the 80, but they told me they really make it to supply it "OEM" to Ford for the Super Duty trucks.  For that reason, it is suitable only for 4.63 and 5.13 ratios.  They make one that will fit the Dodge with its 35 spline axles, but the ring gear mounting surface is about 3/16" too close to the pinion for the Dodge 3.54 and 4.10 ratio gearsets.  Tractech told me they plan to make one for Dodge ratios within a year.

     On snow, you may actually prefer an "open" differential, particularly on side slopes, because any limited slip can tend to make you slide downhill (sideways) as it locks, unlocks, and spins both tires.  The No-Spin is not recommended for the front differential of 4x4s, because it must unlock, or spin a tire, for you to turn.  This rough action strongly affects steering.  Also, if you are a hot-dog who greatly overloads the truck, you may be surprised how easy it is to BEND the axle tubes!  This is bad news (housings cost $$$) in any event, and even more so if you have a Detroit Locker, because the dog teeth inside the Locker will shear off if the axles are badly misaligned from a bent housing or from bent axles themselves.  These teeth then get into the pinion bearings.  Need I say more?

Other locker information on the web


Last update September 19, 2002