The
ARB Air-Locker
is supposed to be one of the strongest and most reliable on the market.
I mounted mine myself, in August 1995.
It was a delicate work to do,
definitively requiring the original Repair Manual from
Toyota,
and also requiring a certain amount of special tools.
I may mention that it is higly possible to do without any specific tools from Toyota, though.
At least in the rear differential of a
4Runner.
Mine worked fine for a little more than one year and about 3000 kilometers. During this time, I made one trip to Sahara, and a lot of local wheelin'. It has always helped me a lot. Used with caution (you may actually tip your truck over if you use it the wrong way), it has taken me through and out of some situations that no one belived would be possible with a 4Runner. I have always put a lot of trust in the unit, and with good reason.
But, on my last trip to Sahara, while crossing
Tunisia,
it actually broke down.
I was driving on the Tunisian highway.
Heavily loaded for two weeks of independence in the desert.
Suddenly, I heard a strong knocking sound in the truck.
I immediately hit the brakes,
and within three seconds my truck had come to a stop.
After a short while of wondering and investigating what may have been the cause of the sound, I drained the oil from the rear differential. And there it was. A lot of metal particles in the oil. It took me almost two weeks to get the truck back to France, which is where I live, and then another two weeks before the truck was finally at home. Disaster.
As you probably realize, this meant that I had to change ring-gear and pinion. Doing this, I naturally chose to change all four bearings as well. By the way, they had seen too much of metal debris to be re-used anyway.
I contacted ARB in Australia. They where very helpful in explaining what was going on. 'Yes, this was a know problem. Today, the unit is modified to avoid this situation. There are now eight bolts where there used to be only four (like in my unit). The bolts are changed to a different type, and locking tabs are mounted on the bolts to avoid that they unwind.'
They sent me twelve(!) new bolts,
complete with locking tabs by
UPS.
But, of course,
I was the one to pay the ring-gear and pinion.
Plus do the work.
They also recommended me to have a mechanical workshop redo my unit so that it can take eight bolts.
Unfortunately, I don't know where I could get such a job done with enough precision.
So, I chose to re-mount the unit with four bolts and locking tabs.
Let's see...
Conclusion:
If you have an old unit,
consider opening it at least for upgrading to the new bolt set.
Assume that ARB will provide you the bolts with no charge.
If you have the possibility,
concider machining your unit to carry the new eight bolt set.
If you have the new unit,
just smile and be happy.
:-)
