LOKKA is an automatic positive locking differential, a novel concept in differential locking technology that delivers affordable traction while still providing differential operation.

 

LOKKA Links -------------------- LOKKA Q & A LOKKA Discussion Typical 2 Pinion Installation - 4Pinion Installation - 60/75 Series

Whether LOKKA is being driven on the bitumen or offroad through deep mud, soft sand or climbing steep rocky slopes, LOKKA's performance is smooth, quiet and reliable. LOKKA Lockers are used in military, commercial and recreational 4WDs worldwide, under some of the most arduous 4WD conditions LOKKA's revolutionary design is extremely rugged . . . yet ingeniously simple. The planetary gears in the existing differential housing are simply replaced with a pair of LOKKA cam and axle gear sets.

This vehicle simply drove in and out of this position for the purpose of demonstrating the capability of twin diff locked vehicle.

Smooth automatic operation	Extremely sensitive unlocking (finger touch)
Quiet operation	One of the most affordable lockers in the world
On and offroad steering is uncompromised	Dependable performance characteristics
Positive locking for 100% traction	Unmatched reliability due to simple design.
Doubles your 4WD's offroad abilities	Ultra resilient, steel alloys for durability
3 Year, unlimited kilometre warranty	Simple installation – Do it yourself fit (most models)

LOKKA can in most cases be fully installed by anyone capable with simple mechanical work in one to two hours. In these cases, no special setup is required since the crown wheel and pinion gears are not upset. No special tools, calibration equipment or expensive diff specialists are required just an installation manual and basic tool kit. Designed for failsafe operation and manufactured to exacting specifications from high strength, heat treated alloys for maximum toughness, LOKKA is a great choice for 4WD drivers who require maximum traction and durability.

The key to the LOKKA's smooth performance is a function of the extremely low profile "driver and coupler" gear sets acting together with the advanced mechanical principal which causes the dynamic engagement and disengagement of the axles. In addition LOKKA's design allows it to relock almost instantaneously meaning that the locking and relocking happen quickly and without harsh noisy action.

LOKKA's operation and effectiveness in comparison to other differentials is summarised below.

Open Differentials and Limited Slip Differentials (LSD's) are designed to distribute enqine torque proportionately to the wheels, allowing the wheels to travel at different rotational speeds when cornering on hard road surfaces or travelling over very uneven ground.

When turning on a hard surface, "open" and LSD differentials use the outside wheel to drive the vehicle, while the inside wheel is allowed to "differentiate" or travel a shorter distance around the turn. The very nature of their design however is detrimental in relation to their ability to deliver equal torque to both wheels, hence traction and 4WD off road ability is severely handicapped.

LOKKA will perform the same as open and LSD differentials when the vehicle is driven under equal traction conditions, ie on road. The LOKKA allows the wheels to "differentiate" around the turn, but reverses the operation in that it transfers the engine torque (hence drive) to the inside wheel, rather than the outside wheel.

Wheel slippage or a loss of traction can occur for many reasons offroad and include ; excess throttle, fast approach speeds, limited wheel travel and negotiation of obstacles that exceed suspension travel (especially independent front suspension vehicles), weight transfer off drive wheels and slippery surfaces such as mud, sand, snow, shale, wet grass etc.

Under these circumstances both the normal and even LSD differentials will allow the wheels with the least resistance to spin. Thus the wheels with traction do not obtain any real drive and the vehicle will lose speed or stop. LSDs will assist under these circumstances but only if they are in good condition and only if there is enough resistance on the spinning wheels to activate the clutch pack and allow drive to the wheels with traction. Contrary to popular belief, even a new LSD will allow a lifted wheel to spin freely with no drive to the wheel with traction.

The LOKKA drives both wheels except when the vehicle is turning on a hard surface, so that irrespective of suspension, transmission or engine type, all wheels are being driven equally therefore the vehicles traction (or 4WD offroad ability) is significantly improved.

LOKKA eliminates excessive tyre wear and drive train damage common with other types of lockers, and prevents one wheel 'spin-up' and resultant possible axle sheer. Approach speeds can be lowered, allowing more controlled 4WD driving which reduces vehicle deterioration. Tracks are not degraded by wheel spin or by repeated attempts to negotiate a difficult obstacle, engine braking is improved and 4WD confidence is substantially improved by the increased ability of the 4WD to tackle difficult obstacles with safety.

Due to its sensitive mechanism the LOKKA operates smoothly and is quiet in its operation. This results in one of the most important advantages of the LOKKA – Its ability to allow smooth differential action with almost uncompromised steering means that the vehicle can be steered to gain best advantage, unlike other lockers which limit a 4WD's path to a near straight line or can force a vehicle off line and make steering physically difficult if not impossible.

The most significant feature about the operation of the LOKKA is the degree of smoothness and sensitivity with which the coupling and uncoupling is performed. The LOKKA Locker does not suffer from harsh noisy actions and vehicle twitching. This is acheived through the use of low profile teeth which have a gentle positive pitch and allow smooth, unrestricted uncoupling of the unit, importantly there is almost no backlash between the driver and coupler gears at all. These teeth are used in both coupling and uncoupling actions and have simplified the design by reducing the number of parts.

This in contrast to other lockers which interlock for load transfer but have the side effect that the unlocking is hindered giving rise to the harsh characteristics and locking & unlocking effects

How it works

In comparison to other lockers LOKKA uses an amazingly simple method to couple the axles for maximum traction and to uncouple them for full differential action. ie as required when cornering or driving on hard surfaces.

The actual principal of it's operation while easily demonstrated is difficult to explain in writing - but is as follows.

1. LOKKA has only 4 main parts - a pair of Driver and a Coupler (side) gears for each axle, there are some springs and pins, some have spacers.

2. LOKKA is normally in a fully locked state and only allows differential action by uncoupling the unit when the ground driven force acting on a wheel (either during turning or when negotiating obstacles) forces that wheel to turn faster than the other driven wheel.
ie a turning vehicle's wheels actually travel two different paths with the inside wheel turning in one circle while the outside wheel travels in a larger circle, and therefore faster.

3. LOKKA makes use of two distinctly different sets of opposing forces that exist due to its design - one to dynamically couple the gears when engine torque is applied and the other to uncouple the gears when one wheel overruns.

3a. The locking (coupling) force is applied by the action of the pinion cross shaft acting on a uniquely designed and shaped Driver - the more torque that is applied the harder the unit locks.

3b. The unlocking (uncoupling) action occurs due to the ramping effect between the low profile ramped teeth which force the Driver away from the Coupler (side gear) eg when an outside wheel turns faster than than an inside wheel when cornering. Power continues to be applied to the inside axle. As the turn is completed and the wheels again rotate at the same speed, the outside coupler re-engages.

4. It should be understood that only when there is an external force being applied to a wheel to make it turn faster than the rest of the drive train will LOKKA allow one wheel to differentiate. Slippery surfaces where one wheel would normally break traction in an open diff cause LOKKA to stay locked - even with one or both wheels in the air LOKKA will remain locked.

Pros

• LOKKA is a precision engineered true mechanical locker providing 100% traction.
• The design is ingeniously simple but extremely rugged and reliable.
• It doesn't have wear prone clutch mechanisms like limited slip differentials.
• LOKKA is easy to install - once referred to as the "45-minute locker", it can generally be fitted by the average do it yourself person capable of fitting brake pads.
• In terms of noise LOKKA is extremely quiet, it doesn't cause excessive tyre chirping and nor does it clank loudly as it locks or unlocks.
• LOKKA's low cost makes it one of the most affordable diff locker in the world.

Use & Application

LOKKA is suited to all 4WD applications except the front of some constant 4WD vehicles. They are in use in military, commercial and civilian vehicles and operate under some of the toughest terrain conditions imaginable.

The design is well suited to high horsepower engine conversions such as the typical V8 engine conversions.

The locker design prevents one wheel spin up common in open and LSD differentials which are the major cause of drive train and differential damage.

Whether on road or offroad in mud, sand or hills the LOKKA performs especially well in areas which require maximum traction where fine steering control is needed. Its sensitive uncoupling gives almost uncompromised steering irrespective of fitment to the front or rear differentials.

Now available for

Ford 9" (28 & 31 spline) and Borg Warner (25 & 28 Spline)

Also available for GM (US) 10 Bolt - 7.5", 8.2" & 8.5" and GM (US) 12 & 14 Bolt,
Ford 7.5", 8", 8.8" and 10.25", Chrysler 8.25" & 9.25,
Dana Spicer 25, 27, 28, 30, 35, 41, 44, 50, 60, 70 and 80, VW

 

LOKKA's revolutionary design and unsurpassed smooth performance...
It's affordable and really is the only locker worth driving