portals on a fsj?

[moloss]

This is only my second post but..........has anyone used portal axles from a volvo or
unimog underneth their fsj? I have a 82 cherokee wt and was wondering if any of you guys with a phd in
fsj would know anything about this..........I don't have the money right know for this but
the idea keeps running through my head.........thank you Chris.

[andy d]

educate me, what is a portal axle?. i ve never heard the term before.

[porkchop]

Moloss, welcome the greatest place for your FSJ besides the trail. This topic has been discussed in the past but I am pretty sure no one has done it yet. Do a search and you should be able to find the info you need. Once again WELCOME!!!

What are portal axles?

"Front and rear axles are solid and of the portal type, meaning that the axle tube and differential are situated well above the centerline of the wheel. Hub reduction gears transmit the power down to the wheels. Portal axels allow tremendous ground clearance while maintaining a low center of gravity. The hub gears reduce stress and strain in the rest of the drivetrain, since maximum torque is reached only at the wheel itself!"

http://www.killeraxles.com/assets/images/dsc00203.jpg

And here is a good link with some good info http://www.west-4x4.demon.co.uk/page2.htm

Hope this helps, Andy.

[ July 20, 2003, 06:40 AM: Message edited by: porkchop ]

[scotty]

prollem with mog or portal axles is aviability. a set will run you at least $3000 :eek:

the mog axles are heavy,and will require the use of a mog xfer case,or to make mods to the axle,as the portal deisgn,with only 2 gears in the reduction drop boxes causes the axles so spin backwards form what they normally would.last an not least downside for a mog axle is that they need to be covnerted from their "torque tube" design to a conventional drivesahft.

volvo portals are quite a bit lighter,and i believe use a 3rd gear in the portal end to make them spin the right way.

1 plus for the mod axles(as im sure you know) is that they come with factory cable selectable lockers :cool:

it would be cool to be able to put 235/75s on your rig and have the same strength and clearance as a rig with a d60 and 38s :D the other thing to consider is that the mog axles are a 3.54 R&P with 2-something reduction at the portals-7something to 1 total :eek: a welcome addition for a hardcore trail rig,but not too higway friendly unless you run a 60"+ tire on your daily driver ;)

i cant remember the reduction on the volvos,but typically a portal axle is geared LOW due to its basic design.

not to discourage you from doing it,but there are lots of factors to consider smile.gif

[porkchop]

YOu can get them here pretty cheap, but shipping might kill you. The front axle is $1100 and the rear is $750 http://www.killeraxles.com/html/used_unimog_axles.html

[porkchop]

Here is a good breakdown of the axles. http://www.killeraxles.com/html/mog__axles.html

[Stuka]

You also need a 4 link witht hem. As they will cause INSAIN axle wrap if used with leaf springs. Because of the extra leverage caused by the hubs being below the axle centerline.

[andy d]

thanks for the info. the original vw bus used reduction gears on the trans axle. the main unit was identical to the one in a bug, but they flipped the ring gear and that allowed for the direction change caused by the gears in the hubs

[HeepofaJeep]

I would think you could run leafs, but you would DEFINATELY have to set up a traction bar.

[Will Morris]

Running them spring under would also help. The Volvo military rigs that use Volvo portals use spring under leaf spring suspensions. Also, the Volvos don't use 3 gears in the portals, just 2 with an overall gearing of something like 7:1. I think it's doable with leaf springs, you'd just have to have a good traction bar. I mean people run 4-6" blocks in the rear. Some vehicles come from the factory that way. I'm not saying it's the best thing to do, but people do it and it is possible.

Will

[ July 20, 2003, 05:23 PM: Message edited by: Will Morris ]

[paddyp]

Differential Engineering (http://www.differentialeng.com/hummer9.htm)

This company combines F*rd 9in axles with Hummer portal boxes on the end, with a variety of gear ratios (uses 9in gears). Looks pretty cool, but I have no idea how much they would cost. Custom setup, so probably $$$.

[Stuka]

those HUMM9's are sweet. Wish I had the money for those hehe.

[Will Morris]

Yup, I've seen those before. I don't really think it's that great of a setup and probably costs a ton of money which to me isn't worth it for that extra couple inches of clearance. If I were going with portal alxes, I'd go with Mog axles because they're bomb proof and have selectable lockers. I think it's the ultimate trail axle if you can sort out the suspension and torque tube mess.

Will

[scotty]

will,how do you deal with the axle spinning backwards issue on the volvo axles? ive heard it coms up with the mogs,and was under the impression that the volvos didnt need to have the diff flipped or a certain xfer case used. is it just that no one is really using the volvo axles in trail rigs like they are mogs?

whats the scoop? smile.gif

there is a mog in my storage place. everytime im there i look at it and wonder if there are cameras and what the owners would think if they came to pick it up and found it on blocks with the axles missing :D

[paddyp]

there is a mog in my storage place. everytime im there i look at it and wonder if there are cameras and what the owners would think if they came to pick it up and found it on blocks with the axles missing I think the same thing about the big 2.5 truck just inside the base gate. I wonder if I could grab the Rockwells without the guards noticing, and put my 44s in their place. I would leave them one of the Rockwells :D :D

[Will Morris]

Scotty, as far as I know, you don't have to worry about the driveshaft spinning the other way. What they may have done, but I don't know for sure as I'm not a Volvo portal expert, is a trick very similar to the Humm-9 portal. To make the Humm-9 portal, Differential engineering used hummer portal boxes which only have two gears in the portals so the pinion would be spinning backwards. To solve this problem they took the whole 3rd member out and flipped it upside down making it a high pinion and reversing the rotation of the pinion. This is very easy to do in a 9" obviously and they did some oiling mods to make up for their wacky high pinion setup. So, as far as I know, the Volvos were probably built with their 3rd members designed initially in a similar fashion. I've seen some Erocc boys running them so they're making it onto th hardcore trails. I'll see if I can find anything else later, but right now I have to run to work.

Will

[scotty]

cool. thanx for the info,will :cool: