Portal axles

[4runner DOA]

So my uncle here thinks he knows things and he's never been off road other than dirt bikes.

Let's talk portal axles. How strong are they. Why don't you see it more. And why the fuck should I think a military Humvee with bullet proof doors is actually capable of running major rock crawling trails.

 

[stumbles]

I think they are plenty strong. If you check out rock crawling they are pretty poplular. Jesse Haines Fab does really cool stuff with the Hummer portals. You see them on a lot of custom axle housings.

 

[4runner DOA]

I think they are plenty strong. If you check out rock crawling they are pretty poplular. Jesse Haines Fab does really cool stuff with the Hummer portals. You see them on a lot of custom axle housings.

View attachment 4940

Guess I should have clarified. Let's keep it Hummer specific. Not custom buggy. There's a reason you don't seen Hummers out on the trails.

 

[stumbles]

Guess I should have clarified. Let's keep it Hummer specific. Not custom buggy. There's a reason you don't seen Hummers out on the trails.

I don't think you see Hummers on the trails because they are massive, don't have that much wheel travel, and are expensive.

 

[theesotericone]

Guess I should have clarified. Let's keep it Hummer specific. Not custom buggy. There's a reason you done seen Hummers out on the trails.

Let's not keep it military spec Humvee specific. None of us will ever own own so it's a pretty pointless argument. Could a mil spec Humvee do Hammer trails? I bet it could.


But back on topic. You don't see them often because car manufacturers already have 2 systems for 4x vehicles. IFS and SFA. There's no way Toyo, Ford, Dodge, Chevy or any other manufacturer will change to a portal axle system. That's why you don't see them often. Land Rovers working on a prototype portal axle rig and Mercedes uses them in Unimogs.

As far as them being stronger I would bet a lot of money that they are. Think there's a reason the military uses them? Putting all the reduction in the hub assembly keeps all that torque there where it's less likely to break other components. Also take a look at what it does for ground clearance. This is a photo of the Land Rover Rhino on portal axles.

I want one. lol

 

[4runner DOA]

I don't think you see Hummers on the trails because they are massive, don't have that much wheel travel, and are expensive.

Pretty much what I thought. My uncle was trying to tell me that they have more wheel travel than my 4runner.

 

[theesotericone]

Pretty much what I thought. My uncle was trying to tell me that they have more wheel travel than my 4runner.

Extended travel coilovers on your rig give you 9" of travel. The same as a Humvee. Except it also has 16" of ground clearance, a lower gear reduction, and 37's on Hutchinson Beadlocks. It also has an upgraded TAK-4 suspension that gives it 14" of travel.

http://www.trucktrend.com/cool-trucks/1110dp-october-2011-military-power-the-humvee-gets-a-lift/

 

[azmtnbiker45]

I think they are plenty strong. If you check out rock crawling they are pretty poplular. Jesse Haines Fab does really cool stuff with the Hummer portals. You see them on a lot of custom axle housings.

View attachment 4940

That is just sexy!

 

[Nicklovin]

Saw a Hummer crawling at cleghorn once, it was interesting...

 

[Itaro]

Extended travel coilovers on your rig give you 9" of travel. The same as a Humvee. Except it also has 16" of ground clearance, a lower gear reduction, and 37's on Hutchinson Beadlocks. It also has an upgraded TAK-4 suspension that gives it 14" of travel.

http://www.trucktrend.com/cool-trucks/1110dp-october-2011-military-power-the-humvee-gets-a-lift/

That TAK-4 looks like it gave the Humvee a body lift

 

[Crawlorado]

I would love to find an inexpensive military Humvee! the ground clearance is amazing and the portal hubs allows small CV axles and the freaking AMC 20 differentials to survive 37" tires or bigger. I have seen Humvees have good travel when the stiff springs are swapped out. The Portal allows for a flatter CV angle at ride height and therefore more down travel. There are only a couple down sides to the portals that I can thing of... You need a very positive offset wheel so that there isn't a ton of scrub radius, and with the two gear portals like the Humvee, the differential has to be flipped or you need a rear engine setup to make things go the correct direction. The Humvee uses upside down AMC 20 diffs. Another thing I like about the military Humvee is that they are surprisingly light. Curb weight on one is 5200 pounds and that is with the heavy steel wheels, run flats, and a 750 pound diesel engine. I would love to get one and put an aluminum block LS in it and aluminum wheels and get it below 5000 pounds. My Colorado is 5600 pounds for comparison!

 

[KevinK]

Let's not keep it military spec Humvee specific. None of us will ever own own so it's a pretty pointless argument. Could a mil spec Humvee do Hammer trails? I bet it could.


But back on topic. You don't see them often because car manufacturers already have 2 systems for 4x vehicles. IFS and SFA. There's no way Toyo, Ford, Dodge, Chevy or any other manufacturer will change to a portal axle system. That's why you don't see them often. Land Rovers working on a prototype portal axle rig and Mercedes uses them in Unimogs.

As far as them being stronger I would bet a lot of money that they are. Think there's a reason the military uses them? Putting all the reduction in the hub assembly keeps all that torque there where it's less likely to break other components. Also take a look at what it does for ground clearance. This is a photo of the Land Rover Rhino on portal axles.

I want one. lol

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/

 

[AssBurns]

I would love to find an inexpensive military Humvee! the ground clearance is amazing and the portal hubs allows small CV axles and the freaking AMC 20 differentials to survive 37" tires or bigger. I have seen Humvees have good travel when the stiff springs are swapped out. The Portal allows for a flatter CV angle at ride height and therefore more down travel. There are only a couple down sides to the portals that I can thing of... You need a very positive offset wheel so that there isn't a ton of scrub radius, and with the two gear portals like the Humvee, the differential has to be flipped or you need a rear engine setup to make things go the correct direction. The Humvee uses upside down AMC 20 diffs. Another thing I like about the military Humvee is that they are surprisingly light. Curb weight on one is 5200 pounds and that is with the heavy steel wheels, run flats, and a 750 pound diesel engine. I would love to get one and put an aluminum block LS in it and aluminum wheels and get it below 5000 pounds. My Colorado is 5600 pounds for comparison!

Never knew humvees were that light! It would be pretty damn cool to have portal axles, but a humvee is just too wide to make a good trail rig. It would be cool to make portals fit a midsize truck though.

 

[Arcticelf]

Pretty much what I thought. My uncle was trying to tell me that they have more wheel travel than my 4runner.

Portal axles and wheel travel are totally unrelated things.

The biggest reason, IMO, we don't see them more is top speed limitations. The secondary factor is the torque they put on the axle housing, which requires everything in the support links to be stronger (portal offset directly equals a lever arm acting on the housing, something you don't see when the wheel center is aligned with the axle center).

Also, check out these guys: https://www.proformance.com.au/copy-of-live-axle-portal-hub

especially this: https://www.proformance.com.au/4wd-trophy-trucks

 

[KevinK]

Jordan Pellegrino did alright in his fully independent, on portals, Ultra4 at KOH. He did overheat the difs, but has since added dif coolers.

http://instagr.am/p/Buy_OWPDsWj/
74Weld is killing the portal game.

https://www.instagram.com/stories/highlights/17975632546069212/

 

[AssBurns]

Portal axles and wheel travel are totally unrelated things.

The biggest reason, IMO, we don't see them more is top speed limitations. The secondary factor is the torque they put on the axle housing, which requires everything in the support links to be stronger (portal offset directly equals a lever arm acting on the housing, something you don't see when the wheel center is aligned with the axle center).

Also, check out these guys: https://www.proformance.com.au/copy-of-live-axle-portal-hub

especially this: https://www.proformance.com.au/4wd-trophy-trucks

Well portal axles and wheel travel are sort of indirectly related. Usually the limit on up travel is wheel clearance, not necessarily suspension or CV joint limits. So if you moved your wheel center down a few inches, you'll be able to achieve more down travel while still letting your wheel travel up to the limits of wheel clearance. It will put your CV axle at closer to a 50/50 ratio on up and down travel instead of mostly down travel like most suspension setups are. Sure you'll need to adjust your shock/coilover mounting and bump stop locations, but that's easy in comparison to building portal axles to fit.

 

[Arcticelf]

Well portal axles and wheel travel are sort of indirectly related. Usually the limit on up travel is wheel clearance, not necessarily suspension or CV joint limits. So if you moved your wheel center down a few inches, you'll be able to achieve more down travel while still letting your wheel travel up to the limits of wheel clearance. It will put your CV axle at closer to a 50/50 ratio on up and down travel instead of mostly down travel like most suspension setups are. Sure you'll need to adjust your shock/coilover mounting and bump stop locations, but that's easy in comparison to building portal axles to fit.

True. But at the point your building portal axles, body work clearance shouldn't be a limiting factor...

 

[AssBurns]

True. But at the point your building portal axles, body work clearance shouldn't be a limiting factor...

Well at a certain point you can't just keep cutting the body. You can only cut so much before you run into the hood, or headlights. Portals will still net you more travel without binding CV's.

 

[OlDirtyBilly]

This is probably my favorite truck with portals, and he explains some of the drawbacks like axle wrap. Also a little crazy how small a squarebody on 42s looks in Alaska.

 

[AssBurns]

This is probably my favorite truck with portals, and he explains some of the drawbacks like axle wrap. Also a little crazy how small a squarebody on 42s looks in Alaska.

Yeah leaf springs and portals with big tires is a recipe for axle wrap issues. With links it's much easier to control since you can just increase the vertical separation of the upper and lower links on the axle side. Normally the rule of thumb for link separation is about 25% of your tire diameter, but with portals, you are effectively increasing your tire radius by whatever height the portals are, so that is a factor to consider when building linked suspension and keeping the strength where needed.