Thread: What are Portal Axles?

Google is your friend

[ame="http://en.wikipedia.org/wiki/Portal_axle"]Portal axle - Wikipedia, the free encyclopedia[/ame]

Wagoo (Bill) would be the best person here to answer this question, not only becasue of his amazing wealth of knowledge on 4x4, 6x6 and most offroad vehciles and trucks from the last centery, but also since he has fabricated his own and uses them regulary with great success.

I dont know who made the first or came up with the concept. But basicly imagine a small gearbox at the end of each axle, where the wheel bolts up. This small gearbox will redeuce the axle ratio and also by its physical nature put the center of the wheel lower than the center of the axle. this gives the vehcile more ground clearance, not only under the chassis but under the diff/axle...kinda like fitting big tyres... If you get the chance look under a Army Unimog...

[ame="http://en.wikipedia.org/wiki/Portal_axle"]Portal axle - Wikipedia, the free encyclopedia[/ame]

Originally Posted by John58

I've seen Portal Axles mentioned here and there in magazines, etc, but I have no idea what they are. Can anyone explain (preferably in words of no more than 2 syllables - I sometimes struggle with technology!) what they are, how they work and why you would want them - I gather they are hugely expensive.

Cheers

John

Basically a portal axle setup raises the diff centre above the centreline of the wheels with a drop down box bolted onto the ends of the diff housing. This gives 4 or 5" of extra clearance under the diff pumpkin and raises the vehicle the same amount. Most military vehicles are so fitted, regards Frank.

I became aware of Portal Axles when I was not long out of school installed a old Hunhouse (VW Kombi) engine & gearbox into my Beetle. Very happy with myself until I discovered I had 4 Reverse gears & One forward gear.

You see the old Kombi had portal rear axles, (have a look under the back of one) and the crownwheel was on the otherside of the pinion in the gearbox to compensate for the direction change in the hub reduction.

pic below shows portal vs standard axle

I think I get it... Thanks folks!!

John

WRT ADR's and roadworthies:
- are portal axles legal for road registration?
- will they require an engineers report?
- any other issues that need to be known?

These are the ones made for Landies by MaxiDrive: