Portal axles

[Arcticelf]

Agreed and either option would point to the biggest reason why portals aren't a common place in 4x4 modifications - Cost.
However if we took cost out of the question, what are the other pros or cons of portals?
I was just reading a couple of forum threads about portal axles... And one of the complaints was that there was no real information. Whenever someone mentions portals, the common responses are,

• "Too expensive. Not necessary. Just do a lift."
• "Just get a Unimog"

Reading those threads, there was some information where they were even referencing some portal axle manufacturers like Axletech, Tibus, Marks4wd, 74weld.com, etc. But for the most part, there were just snarky comments about costs and referencing that the person buy a mog or a pinzgauer or even a Humvee H1. It was actually quite annoying reading those because rather than having a proper technical discussion on the pros and cons, especially in layman's terms, we're forced to listen to the opinions of someone who doesn't think they're a good idea simply because he can't afford them and therefore no one else should either.
@Arcticelf, @Slim-Whitey - thank you for making this a proper discussion with some really good information.

Trying to get more information, I found this article online - How portal axles work

Thanks. I'll see if I can find the drawings I did of a reverse 4 like setup for a Tacoma. Another thing everyone says can't be done.

 

[knightjp]

Does the replacement for the HMWWV (Hummer H1), the Oshkosh JLTV, have independent suspension and portal axles as well? Thinking since it worked out for the Military in the Hummer for 30 years, why not use it?

Came across this article - 4 Things to Know About Portal Axles

 

[Stairgod]

So apparently portals are not necessarily a limiting factor to attainable top speed?
I could not find the top speed of a G-wagen, but the Brabus also uses portals and has its speed limited at 130 mph due to tire rating. Hmm

 

[Stairgod]

Agreed and either option would point to the biggest reason why portals aren't a common place in 4x4 modifications - Cost.
However if we took cost out of the question, what are the other pros or cons of portals?
I was just reading a couple of forum threads about portal axles... And one of the complaints was that there was no real information. Whenever someone mentions portals, the common responses are,

• "Too expensive. Not necessary. Just do a lift."
• "Just get a Unimog"

Reading those threads, there was some information where they were even referencing some portal axle manufacturers like Axletech, Tibus, Marks4wd, 74weld.com, etc. But for the most part, there were just snarky comments about costs and referencing that the person buy a mog or a pinzgauer or even a Humvee H1. It was actually quite annoying reading those because rather than having a proper technical discussion on the pros and cons, especially in layman's terms, we're forced to listen to the opinions of someone who doesn't think they're a good idea simply because he can't afford them and therefore no one else should either.
@Arcticelf, @Slim-Whitey - thank you for making this a proper discussion with some really good information.

Trying to get more information, I found this article online - How portal axles work

Here are the biggest issues I can think of for retrofitting portal axles into a vehicle not originally designed for the.
Biggest issue is frame design. The axle tube will come into contact with the frame rails earlier in the suspension cycle because of the "lift" given by the portals. Assuming you want to keep the vehicle as low as possible to keep the COG manageable, the frame rails will need to be notched and or rebuilt to accommodate. Obviously if you are mounting 40s and the suspension will need to be bumped before the axle hits, then this is not an issue.
Similarly, if using a portal on an IFS set up, LCA and UCA location will need to be altered, as well as beefing up the components to withstand the "leverage" of the portal.

On a linked solid axle, portals require not only a more robust link mount, but more separation of those links than on a typical solid axle. The rule of 25% of tire size link separation does not work for portals. Iirc a Mog has close to 40%(going by memory, I might be off a bit). So with more link separation as well as beefier axle mounts, more room is needed and again frame issues may come into play, especially since the upper mount will probably be the one you move up, as it would be ludicrous to use portal axles and put the lower link mount 10" below the axle tube.
Lastly the actual need for portals needs to be addressed. Is the extra clearance under the diffs really needed? Is the expense and work going to make enough of an impact of be worth it?
Anything can be done. Sometimes things are down for the hell of it. I have quite a bit of work done on my truck that wasn't really needed, but I wanted it and could afford it.
In the end, your money, your time, your vehicle. So your choice.

 

[Stairgod]

Does the replacement for the HMWWV (Hummer H1), the Oshkosh JLTV, have independent suspension and portal axles as well? Thinking since it worked out for the Military in the Hummer for 30 years, why not use it?

Came across this article - 4 Things to Know About Portal Axles

That article has at least on glaring bit of bad info.
Portals do NOT increase the effectiveness of the brakes. The rotors are on the hub just like a conventional axle so they work in exactly the same manner.

 

[knightjp]

So apparently portals are not necessarily a limiting factor to attainable top speed?
I could not find the top speed of a G-wagen, but the Brabus also uses portals and has its speed limited at 130 mph due to tire rating. Hmm

Well its no TrackHawk. That's for sure. Its power is there for another purpose or maybe just for bragging rights.
Besides anyone who drives an SUV over 100 mph is asking for trouble.
The highest top speed I reach with my truck is about 70mph. If I wanted speed, I certainly wouldn't be looking at off-roading.

 

[knightjp]

That article has at least on glaring bit of bad info.
Portals do NOT increase the effectiveness of the brakes. The rotors are on the hub just like a conventional axle so they work in exactly the same manner.

It would appear that you have experience with portal axles. Am I correct?
If so.. would love to hear the details.

 

[Stairgod]

It would appear that you have experience with portal axles. Am I correct?
If so.. would love to hear the details.

I have limited experience with portals. I have wheeled with a guy that had them, and I have some experience with Humvees.

 

[knightjp]

I have limited experience with portals. I have wheeled with a guy that had them, and I have some experience with Humvees.

Do share...

 

[skyisthelimit64]

Mostly all true, except Toyota did manufacture the Mega Cruiser with portal axles from the mid-90's to early 2000s. It was a military vehicle but also sold privately in limited numbers. Also, I want one. They pop up occasionally on the grey market.

https://www.megacruiser.com/

 

[skyisthelimit64]

Mostly all true, except Toyota did manufacture the Mega Cruiser with portal axles from the mid-90's to early 2000s. It was a military vehicle but also sold privately in limited numbers. Also, I want one. They pop up occasionally on the grey market.

https://www.megacruiser.com/

This is sweet! never had seen one before. kind of look like the H1 with the hardtop version. Do you know where it s been marketed mostly ? also, what was the powertrain it came with?

 

[Stairgod]

How the hell are they getting away with that little amount of link separation with portals??

 

[Notcrow-of-judgement]

Bump

 

[clearock]

How the hell are they getting away with that little amount of link separation with portals??

Not to say I am correct, I would think because of overall weight (what did he say something like 2600lbs) and strength of the mounting points...?

 

[Arcticelf]

How the hell are they getting away with that little amount of link separation with portals??

Wildly overbuilding the links for the weight of the truck?

 

[Stairgod]

Wildly overbuilding the links for the weight of the truck?

The mounts look damn beefy.
Ntm the motor isn't a torque monster.
But portals put upwards of 4x the force on the link mounts compared to a conventional axle.

 

[AssBurns]

Low weight, low speeds, and not too much instant torque on the axles.

 

[4runner DOA]

http://instagr.am/p/CP3iIPThqjm/

 

[Stairgod]

http://instagr.am/p/CP3iIPThqjm/

$$$$$$

 

[4runner DOA]

$$$$$$

I didn't even look at the cost, but I'm sure. No a way a bolt on solution is going to be cheap for something like this.