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Discussion Starter #1
Well, I'm no expert so this isn't going to be a nice quick "How To" thread....

I've been doing my homework, and learning as much as I can about the process so all I'm going to do is post up the pics of my struggles and document whatever learning I do along the way. Anyone with experience who wants to offer suggestions along the way is welcome to jump in here.

I'd prefer to get helpful advice even if I have to go backwards to re-do something... the alternative is to do things wrong, and I'm not interested in that.

So.... here we go:


I've got a set of 404 axles (one steer, one non-steer) and a set of Spidertrax 9" housings. I wanted to do a basic mock-up with one axle and the frame just to see what sort of clearances issues I was going to have.

The first setback was that I didn't have a 55mm socket, or a way to generate 750Lbs of torque to remove the massive hub nuts...so I did the only other thing that I could think of:



I simply unbolted the portal from the intermediate adapter on the axle housing and slid the entire drum brake / portal & inner axle off as a single unit. There is a small tube running around the perimeter of that portal bearing...looks like a brake line with a banjo fitting, but might be some sort of gear oiler?



The mock up with the Spider-9 ended up looking like this. The frame is about 2" shorter than actual ride height will be, so that gives me about 8" of uptravel before I hit the frame. My assumption is that I'll crush the oilpan well before I ever make contact with the frame rails... The wheel center is at the correct height to simulate my 38" tires, and the pumpkin clearance ends up being 18"....pretty impressive.



Here's a shot of the 3rd member removed. I just wanted to see how it looked and how the locker operated. It took me a while to get the 3rd removed, but a quick search on this forum told me to rotate the pig 1/4 turn toward the locker side for clearance of the ring gear. As soon as I tried that, it dropped right out.



I can sympathize at what a pain it must be to R & R a broken shift collar for the locker assembly. There's quite a bit of labor to get the 404 this far apart.

Last night, I jumped on eBay and picked up a Snap-On torque multiplier and a 55mm impact socket. I hate not having the right tools, and it seems like I'm going to need them quite a few more times anyway...

Now that I have those ~10" long "intermediate" axle housings removed it seems like it won't be hard to use them as a template to machine an adapter to mount to the 3.5" axle tube of the Spider-9s. I notice that some guys re-use these intermediate parts and build a flange further inboard on the axle, and other guys build their adapter to go directly to the back of the portal housing. I'm not sure if either has a particular advantage, or if it's just personal preference? :confused:


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Great pics and writeup.
some guys eliminate those 'intermediate' spacer tubes as they are cast (shit)and you cannot weld links mounts to them.(successfully)
"BUT" if you ever are considering going to rear steer, they are great as your width won't change, you just replace them with the steering knuckles and associated steer parts.

Are you just going to cut your flange mounts off of the stock axle tube?
 

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Discussion Starter #3 (Edited)
I think I'm going to use the larger oval-patterned housing (the one that bolted to the back of the portal box) as a template and have that machined with a 3.5" center hole for the new axle tube.

The stock part has a good amount of triangulation (cast-in gussetting) from the lower portal gear up to the tube...I'd like to incorporate a simliar solution with my adapter plate to reduce stresses. It seems like a logical area to also try to sneak in a set of lower mounting brackets for my 4-link heims...and maybe even create a place in that area for the lower coilover mount??


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There is a small tube running around the perimeter of that portal bearing...looks like a brake line with a banjo fitting, but might be some sort of gear oiler?
those are the rear axle breather tubes for the portal box. it allows it to breath through the axle and only have one tube on the outside of the axle vs. the front that has 3 b/c of the knuckles.
 

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Discussion Starter #5
those are the rear axle breather tubes for the portal box. it allows it to breath through the axle and only have one tube on the outside of the axle vs. the front that has 3 b/c of the knuckles.
DoubleJ,

Thanks for the help. :beer:


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Discussion Starter #6
I'm running into some problems with my scrub radius calculations....

According to this diagram, the upper kingpin pivot (shown in image as large red dot) is going to hit the tire with a 7.25" backspaced wheel, and even then the scrub radius isn't all that good.





So, I have a few questions for anyone who knows:

1. What was the backspacing on a factory Mog 20" wheel?
2. Is it possible to use a 17" wheel with lots of backspacing without interference? I'm thinking something like a Hutchinson with 6-3/8" BS... an H2 wheel only has about 4.5" IIRC
3. Will using the new SpiderTrax 1550 Steering knuckles give me a sharper SAI angle to help pull-in that scrub radius value to something closer to 0"?



-G
 

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I used to run a 17" wheel with as much backspacing as was physically possible, from memory it was 135mm, or roughly 5.25", any more than that and the wheel hits near the two top bolts that hold the portal onto the knuckle ( on the other face of where you have "RR" marked on yours above)

I moved to an 18" wheel to run the sticky Baja Claws and that gets rid of that interference point. I run something like 7" backspace now with the 18"s and could run a lot more if I wanted.
 

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Discussion Starter #8
Thanks for those data points....

I think it's going to make sense to get the 8-lug conversions done sooner than later so that I have a proper WMS surface to drop some wheels against to check for interferences.

At the moment I have 3 different wheels at my disposal:

16.5"H x 9.75"W w /3.75"BS - Traditional Chevy "wagon" wheel
17.0"H x 8.50"W w /5.56" BS - H2 Stock "takeoff" wheel
16.5"H x 9.75"W w/ 7.25" BS - H1 Non-Recentered wheel

If none of those will fit, I'll have to do some soul-searching and either go to a larger diameter wheel, or use a lot less backspacing and gain even more scrub radius than I have now.

Fortunately, my eBay victory (55mm socket) showed up today in the mail. Now all I need is the Snap-On torque mulitplier (also coming off eBay) and I should be able to break those assemblies down the rest of the way.


:usa:
 

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Unfortunately, all of those wheels are going to be limited by the same inteference point, I was in the same boat when I built my first set of wheels for the Mogs, very dissapointed with the scrub radius. 18"s or 20"s really are the way to go.

Also, for what you are doing you shouldn't need to pull the boxes down unless you want to recondition them or strip all the brakes off. If you undo the little bolts around the seal housing where the axle shaft runs into the box, you can knock the box off the shaft. The shaft will come out with both bearings and the top gear.
 

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...It took me a while to get the 3rd removed, but a quick search on this forum told me to rotate the pig 1/4 turn toward the locker side for clearance of the ring gear. As soon as I tried that, it dropped right out...

some strategic grinding will allow you to take it out even more freely in the future and also helps to get it back in!
 

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I run 17" wheels with 6" backspacing, but I have a disk brake set-up. I bought the rig from Joel Kelsey who had Allied rims (6 1/4" backspacing) and now I run Walker Evans (6")

Are you planning on switching to Disk brakes?
 

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Discussion Starter #12
I run 17" wheels with 6" backspacing, but I have a disk brake set-up. I bought the rig from Joel Kelsey who had Allied rims (6 1/4" backspacing) and now I run Walker Evans (6")

Are you planning on switching to Disk brakes?

Yes, definitely going to a disc brake setup.

Before I make any new wheel/tire decisions I'm going to get that conversion done and take a look at how my existing H2 wheels fit (or don't). At least I'll be able to take some measurements with those before making any more decisions.


-G
:usa:
 

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Discussion Starter #14
The progress has been slow, but I'm learning a lot along the way....

like you cant just "pull" a 6-lug UniMog hub off the portal housing......you have to really PULL!!!


This will be a review for the experienced guys, but for anyone dealing with 404s for the first time, this information will be really helpful.

Step 1: Build a hub puller.... you can't weld to the drum to create a convenient mounting plate since it's too "iron-ic". Maybe if you've got an arc welder and special rods....I didn't, so I bought a piece of thick plate and transferred the hole pattern to it.



Attach the hub puller to the hub and get the longest breaker bar you can find. Get ready to "earn" your success.



If things work out well for you....this is what you'll see after an hour of effort (at least that's how long I struggled) :smokin:



This is the portal box seperated into two parts. Now I understand why it was not possible to remove the axle shaft from the portal housing by removing the outer bearing cover and breather assembly! :D




That's about it for now.... I need to revise the puller a bit to make it work better and more efficiently. I still have 3 more hubs to do, and I don't want to spend nearly this much time pulling those hubs too...



-G
:usa:
 

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ow I understand why it was not possible to remove the axle shaft from the portal housing by removing the outer bearing cover and breather assembly
I have done it that way, just gently tap the box off the shaft and the bearing pulls the outer cone out with it. :confused:
 

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Discussion Starter #16
WB,

You know, now that I see how it all goes together and understand it a bit more you're right.....it wouldn't really hurt anything to pull it from the outside either.

Good suggestion!

As I've said before....a lot of this is very new to me. :D



-G
:usa:
 

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I built a very similar puller when I did my hubs. I found it was about an hour of straining to do it by hand and I also twisted the 3/4 drive nub off my Harbor Freight socket wrench. I had the best luck with a 1" impact gun and I simply resigned myself to using several bolt/nuts before I was done (most of which I seized so badly I had to cut them off the puller).

Also if you get the puller tightened and smack the hub on the side of the 'spindle' part the vibration is usually enough to get the whole thing to jump. Then you can do it again.

If I ever have to pull apart my 8 Lug converted hubs I am gonna try and built my next puller out of like 1 /14 or larger ACME threaded rod.

I strongly recommend a press for re-assembly.

P.S. Anti-seize is MUST for this project.
 

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Ill be following this closely as im thinking about using mog portals on a couple of steering axle assemblies with custom disk brakes, i havnt decided what axle assemblies to use but they need to be beefy cause there will be a cummins powering the rig, im thinking about a "plate" with some gussets to the knuckle to bolt the portals to the knuckle, something that will relieve stress on the cast portals and give me a point to mount steering arms and shocks as far outboard as possible. i would like to use knuckles other than the 404 pieces because i dont like the kingpin issues, were gearheads, anything is possible and ive got a machine shop and forge at my disposal, let me know if theres anything i may be able to help with.
 
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