98 4Runner Ltd. 135,000km
When I push the RR Diff Lock button the light just keep flashing. I tried L4, Neutral same result just keep flashing. Any thing I should check b4 send it to the dealer ?

 

In 4Lo, drive ahead at idle speed while turning throught an S shape. It'll lock up when the splines engage.

 

My concern is in case I got stuck and the rear wheels are spinning even in L4. If I cannot get the RR Diff Lock engage at that moment I will be in trouble. I wonder is this a common problem for 4Runner.

 

Both will not be spinning at the same time. A touch of gas will cause one to spin, and line up with the one with traction, or different amount of slip, and the locker will engage. Stop worrying about it. Take it out and prove it for yourself.

 

You should have your locker already engaged before you get in a potentially stuck situation.

 

That's very true, and good advice.

 

Does it engage now?