Why is my Jeep Rubicon’s diff-lock not engaging?

Rubicon ARB diff housing cover



I recently bought a ’10 Jeep Wrangler Rubicon, but every time I drive a trail people tell me the front locker isn’t engaging. This would explain why the diff-lock light keeps flashing.

So, after fishing around, I’ve found a lot of online information that suggests the Rubicon lockers aren’t that reliable, and often give problems, is this true?

If so, what’s the problem, how can I fix it, and how do I prevent it from happening again.

Answer: As far as durability is concerned, the JK Rubicon front & rear Dana 44 Tru-Lok selectable lockers are not the best on the market.

However, if used on vehicles with “mild” tyre sizes (35-inches and smaller), they’re generally up to the task.

The most common issues are caused by the following:
  • Broken locker wiring or connector plugs on the diff casing
  • Faulty magnetic actuator, which we can repair or replace, but it requires removal of the axle shafts & carrier
  • Damaged locker sensor switch, which can also be replaced, but requires removal of the axle shafts & carrier to install

Sadly, there’s not much one can do to prevent the common issues, apart from periodically checking the wiring and connectors for correct routing & fitment, as well as ensuring that there’s clean oil in the diff.

If you remove the diff cover and are able to move the locking ring to the lock, or unlock position manually, then it is probably the actuator that has either worn out, or is sticky due to oil contamination.

Unfortunately, in the event of breakage or malfunction of the locker unit, no spares are available separately, which means you’ll have to replace the complete unit with one of the following:

  • Factory replacement unit
  • Nitro Gear (aftermarket) factory replacement unit
  • Ox Locker, which fits the standard 32-spline rear and 30-spline front axle shafts
  • Ox Locker, which requires upgraded 35-spline shafts (a good idea if you are breaking shafts)
  • ARB Air Locker, which requires upgraded 35-spline shafts (also a good idea if you are breaking shafts)
  • Auburn Gear Ected Max Locker, Rubicon rear only, which requires upgraded 35-spline shafts (Also a good idea if you are breaking shafts)

We can supply you with any of the above-mentioned solutions. Give us a call if you’re looking for a price.

ANSWER SUPPLIED BY: Ronald Hairbottle

4×4 Traction

Tel: (015) 293 0736

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