Portal axles

[Greggry [OP]]

I always wondered why more companies out there didn't design some sort of geared hub system to gain ground clearence. Here is a mopar setup on a jeep. According to the 4wd mag a complete front and rear axel is 20K+, plus a bunch more for upgrades to shocks and everything else. Crazy expensive... Cool though...

[brianh]

I think you answered your own question. It's expensive. I've wheeled HMMWVs extensively though. I can say they do work.

[Archy Chris]

Greggry previously said:

I always wondered why more companies out there didn't design some sort of geared hub system to gain ground clearence. Here is a mopar setup on a jeep. According to the 4wd mag a complete front and rear axel is 20K+, plus a bunch more for upgrades to shocks and everything else. Crazy expensive... Cool though...

Wow! That is expensive.

[nkybrad]

You can get them for much cheaper. But you are still looking at about half that ($8-10k). Most use old Unimog axles and do the custom work theirselves. They are amazing axles and give ridiculous amount of clearance and are tough as nails, but on the flip side parts are not easily and readily available for them and again, the initial investment can be hefty.

[Layonnn]

The few reasons that i know of:
-expensive
-expensive to maintain
-noisy
-very limited top speed (some of them are around 50-60mph)

You don't really need to modify the suspension very much. You can run what ever current configuration you have, just modify the brackets on the axle to match your suspension type. Since most portals give you a 4-6 inch lift due to their design, you don't need to run much lift in addition to them.

You can see how the red JK on the right has the axle tucked up about as high as they normally do from the factory. He is probably running very little lift.

[BIGGUY]

I'd think that they would also add a fair amount of extra weight so performance and gas mileage would suffer even more than normal.

[Silver-Bolt]

Cost, weight, and parasitic loss.

[Geronimo]

I think Stazworks offers them, though not sure if for the FJCs. For $20K, why not just buy a Unimog?

[4Mogger]

Layonnn previously said:

The few reasons that i know of:
-expensive
-expensive to maintain
-noisy
-very limited top speed (some of them are around 50-60mph)

You don't really need to modify the suspension very much. You can run what ever current configuration you have, just modify the brackets on the axle to match your suspension type. Since most portals give you a 4-6 inch lift due to their design, you don't need to run much lift in addition to them.

You can see how the red JK on the right has the axle tucked up about as high as they normally do from the factory. He is probably running very little lift.

Just a few comments from someone who has learned all of this first hand:
1. They are heavy-- but there are lighter options like the Volvo 303's. You don't have to run mog's, but heavy generally does equate to strength.
2. Expensive to maintain? Expensive to build but to maintain I would say that would depend upon how much they are abused. If you are not adding them to a high HP rig that you plan to abuse on a high traction surface-- like rock-- then maintenance is minimal. They can handle a lot of power but not rapid loading/unloading as can be experienced with aggressive driving on rock surfaces.
3. Noisy? Not in the least. They make no more noise than any normal axle. In fact, when they are completely locked up, the operation is actually smoother than a traditional axle with less "hopping" and lurching. They just scrub off rubber.
4. Very limited top speed? Again, not in my experience. The limiting factor is not the axles, but is instead the final gear ratio. I run a little 3.0 Toyota V6 to push my HEAVY rig on 40 inch tires around. I can cruise 70 on the highway easily. Of course the V6 likes to rev. At 60 I am doing 3000 rpm in 5th gear-- about perfect for this motor since it is just entered it's power curve. But it would be hard on a V8 (OK maybe not a Toyota V8 which is in my long term plans) and a diesel is certainly out of the question in this application. A diesel with a final drive splitter would be one solution. It is possible. Point being-- the axles are not the limiting factor. Plus, if you are running portals than you are probably running 40+ inch tires and not spending much time above 60 mph anyway unless you get your tires for free.

Oh, dropped by because I love all things Toyota and would love to have a FJC. But I have a big family-- 4 kids-- so it will likely mean that I will build another 4Runner instead but this time a 7 passenger V8 4Runner mild build on 33's or 35's. Enjoyed seeing you all in Ouray a couple of weeks back. That is just down the road from my place in Montrose and I go there a lot.

[4Mogger]

Silver-Bolt previously said:

Cost, weight, and parasitic loss.

1. Cost? Have you priced a custom 60? Or if we are going to compare apples to apples-- a custom 70? All of this stuff is pricey.

2. Weight? No argument here!!!!

3. Parasitic loss? I have not noticed that at all. But the loss I experience I chalk up to the rolling resistance of 40 in tires running about 17 psi on the highway. More pressure than that and the ride gets rough. This combined with the weight-- which is significant-- certainly equals loss of efficiency.

But then again... I can drive over a 5 gallon bucket with my tires completely flat and never touch it at the lowest point of my axles.
This is the main advantage. I drive mainly rough mountain trails-- like Imogene and Black Bear. I see the average guys bouncing mercilessly. I don't bounce at all. I am on airbag suspension with my tires at 7 psi and I have to hit a 10 inch tall rock before I even feel it.