Everything you ever wanted to know…

A few weeks ago, we were lucky enough to get schooled on Portal Axles while in Melbourne in the most unexpected circumstances.

We were in Melbourne for the Australian Motoring Awards (still not sure how we were invited). Anyway, it just so happened that Leigh Hardman from Mark’s 4WD was at our table. Over a few drinks, we all got to talking.

I’d not spent a lot of time researching Portal Axles, which are standard equipment in military vehicles like the Unimog. But my interest peaked when Leigh mentioned the increases in lift that you could get while maintaining the on-road handling and off-road stability you’d expect from a factory-sprung vehicle.

Now keen to learn more, we made the trip over to Marks 4WD to check it all out. We also got the chance to interview Leigh – read on for what he had to say

So What are Portal Axles?

Portal Axles are basically a modification that raises the height of the axle (and diff housing etc) above the wheel hub, increasing ground clearance. A set of gears then connect the axle shaft to the wheel hub. It has the effect of raising the axle and diff housing higher off the ground, and therefore the body of the vehicle too, giving a true increased ground clearance, and a wider wheel track.

What are the key benefits?

The key benefits are as follows:

Ability to fit 35″ tyres

Combined 6 ” lift (with Portals and 35’s)

Increase in ground clearance – A set of portal axles will raise the lowest point of the differential and the axle by about 4 inches. They will also lift the vehicle by a similar amount by virtue of the fact that the chassis is generally connected to the axles. Importantly, this is true ground clearance – with a traditional spring/shock lift, your diffs and axles remain at the manufacturer heights!

Reduction in pressure on the drive train – The portal axle gears reduce the torque on the drive train reducing the load, and also offsetting the effect of increasing tyre size.

Handling vs suspension lift – This is a big one. Portal axles can help increase the off-road capability of a vehicle because they maintain the manufacturers original suspension geometry. This means you can get significant lift while maintaining close to the handling of a stock vehicle. Even though the centre of gravity increases, the portal axles also increase wheel track slightly which helps offset the effect of the extra height. The key thing it avoids is the sway that you get and boat like handling that often comes with increasing your suspension travel with a traditional spring based suspension lift.

Legality – the team have authority to second stage manufacture, meaning you can get these modifications before you take delivery and as far as anyone is concerned, its totally legal. If you’re retrofitting, they can easily be engineered to state regulations.

And before you head on your road, there are some tips for you to know about winch.