Here's an introduction to portal axles I posted at www.expeditioncampers.com
Chip Haven
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Portal axles provide a lot of ground clearance without a big modification to the stock suspension. This also keeps the vehicle's center of gravity lower than it would be if using a conventional approach (big tires, big body lift) to achieve the same clearance.
Portal axles increase a vehicle's ground clearance by changing the location where the drive axle connects to the wheel. Sitting on level ground, a standard axle extends straight from the differential to the center of the wheel. A portal axle, in contrast, extends straight from the differential to a point near the top of the wheel. A gear case extends down to the hub of the wheel, where it is attached.
Here's an example:
The portal axle adds an extra 6 to 8 inches of ground clearance without making any other modifications to the vehicle. Combine a portal axle with other modifications like taller tires (and suspension changes so the taller tires will fit) and you add as much as 15 inches to the stock ground clearance.
These images are from Portal-Tek, a new company manufacturing custom axles for a wide range of vehicles. See www.portal-tek.com for more information.
Several manufacturers of military vehicles employ portal axles. Best known are Unimog, Pinzgauer, and AM General's HMMWV.
Volvo built a millitary vehicle called the C303 in the 1970's and 1980's. Axles from C303s happen to be the right length to fit Land Rover Defenders and Toyota Land Cruisers. Here's a photo of a Cruiser with C303 axles and a 2 inch OME suspension lift:
The result: 17 inches of clearance under the front differential! This lets you glide over obstacles that others have to work hard to surmount.
You can see more photos of the build-up of this vehicle at
http://tired-iron.mounet.com/Grace4x4/GRBTLC/default.htm
Let's see...portal axles, a central tire inflation system, hydraulic steering at both ends..it's an extreme rock crawler for overland use!
Chip Haven
-----------
Portal axles provide a lot of ground clearance without a big modification to the stock suspension. This also keeps the vehicle's center of gravity lower than it would be if using a conventional approach (big tires, big body lift) to achieve the same clearance.
Portal axles increase a vehicle's ground clearance by changing the location where the drive axle connects to the wheel. Sitting on level ground, a standard axle extends straight from the differential to the center of the wheel. A portal axle, in contrast, extends straight from the differential to a point near the top of the wheel. A gear case extends down to the hub of the wheel, where it is attached.
Here's an example:
The portal axle adds an extra 6 to 8 inches of ground clearance without making any other modifications to the vehicle. Combine a portal axle with other modifications like taller tires (and suspension changes so the taller tires will fit) and you add as much as 15 inches to the stock ground clearance.
These images are from Portal-Tek, a new company manufacturing custom axles for a wide range of vehicles. See www.portal-tek.com for more information.
Several manufacturers of military vehicles employ portal axles. Best known are Unimog, Pinzgauer, and AM General's HMMWV.
Volvo built a millitary vehicle called the C303 in the 1970's and 1980's. Axles from C303s happen to be the right length to fit Land Rover Defenders and Toyota Land Cruisers. Here's a photo of a Cruiser with C303 axles and a 2 inch OME suspension lift:
The result: 17 inches of clearance under the front differential! This lets you glide over obstacles that others have to work hard to surmount.
You can see more photos of the build-up of this vehicle at
http://tired-iron.mounet.com/Grace4x4/GRBTLC/default.htm
Let's see...portal axles, a central tire inflation system, hydraulic steering at both ends..it's an extreme rock crawler for overland use!
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