Builds 74 FJ40 Resto-mod build (4 Viewers)

[nor_cal_cyclist]

Yes - I spec'd a standard LC diff, and 80 series outers (bigger/stronger birfs). Also went with 300m for inner and outer axle shafts.

Springs are custom Alcans - ZERO lift and standard length.

 

[Paul]

So I can run my 40 diffs with 4:88 and arbs with 80 series inner axles??

 

[EWheeler]

So I can run my 40 diffs with 4:88 and arbs with 80 series inner axles??

I don't think the 80 series inner axle is any different than a 40 or 60 series, it is the size of the birfield joint, which dwarfs the 40 & 60 series units. If you want to run 80 series outers with 9.5" center diff, you need to consider what suspension setup you have and how you will setup your steering. If you're spring over like this build, you'll likely need a hi-steer setup, which likely requires aftermarket knuckles & arms. If you are linked, it's likely you can keep the low steer factory arms but need to source an overseas factory arm for the drivers side as you will will need to move the tie rod to the front of the axle as the factory FJ80 tire rod location won't work with the 9.5" diff. Most of this is documented throughout various threads in the Hardcore section. Also lots of info on Pirate 4x4.

 

[Paul]

My front end is SOA and rear is 4 linked from 2008 built by Jeremiah Proffitt. I’m putting in a 5.3 and 93 nv4500. I would love to run a atlas. Looking to upgrade my axles and maintain my 40 diff builds.

 

[Paul]

Thanks for the comments

 

[nor_cal_cyclist]

With the suspension almost done, was about time to get my wheels/tires figured out so it could become a "rolling chassis." Due to the current shortages and extended backorders, 37x12.50's were REALLY hard to find...picked up a set of my 2nd choice, 35x12.50 Mickey Thompson Baja Boss MT's and some Icon Rebound Pro's to mount them on:

I figure I can always swap the tires out if I'm not happy with traction or wear or size, once more stock becomes available. Hoping these work, as between the difference going from 37's to 35's and switching to the Icon wheels instead of the Hutchinsons, I'll save 40-45lbs per corner.

 

[TRAIL TAILOR]

A little more done.

J

 

[nor_cal_cyclist]

Been a while since my last update, so thought I'd post.

"HOUSTON, WE HAVE A PROBLEM...."

Looks like the steering arms provided for my hi-steer setup don't quite work with the suspension:

After much grief and pulling the few remaining hairs from my head, the project is currently in a holding pattern while I work on getting it into a shop to complete the build.

 

[EWheeler]

Been a while since my last update, so thought I'd post.

"HOUSTON, WE HAVE A PROBLEM...."

Looks like the steering arms provided for my hi-steer setup don't quite work with the suspension:

View attachment 2960649

After much grief and pulling the few remaining hairs from my head, the project is currently in a holding pattern while I work on getting it into a shop to complete the build.

It looks like you could gain AT LEAST 1" of clearance between your tie rod and leafs if you had shorter leaf spring perches that used regular u-bolts. Also, I don't think full droop on BOTH sides of the chassis is really a real world condition for a truck like this. Not to say you should be OK with any interference at full droop, but before you go spending thousands of dollars on new parts, I think you should lower the leaf spring perches and then flex out the suspension to see what you actually need. There are too many trucks setup spring over with those knuckles and steering arms that work, for you to say this can't work.

You could literally lower the whole chassis probably 1.5-2" by the looks of things if you went with a low profile spring perch that sets right on top of the axle tube.

 

[nor_cal_cyclist]

It looks like you could gain AT LEAST 1" of clearance between your tie rod and leafs if you had shorter leaf spring perches that used regular u-bolts. Also, I don't think full droop on BOTH sides of the chassis is really a real world condition for a truck like this. Not to say you should be OK with any interference at full droop, but before you go spending thousands of dollars on new parts, I think you should lower the leaf spring perches and then flex out the suspension to see what you actually need. There are too many trucks setup spring over with those knuckles and steering arms that work, for you to say this can't work.

You could literally lower the whole chassis probably 1.5-2" by the looks of things if you went with a low profile spring perch that sets right on top of the axle tube.

The perches will yield about 1"-1.5". Front Range suggested to check caster as well as getting rid of the spring hangers that tuck up tight to the frame. Once I get it back into a shop, will have EVERYTHING looked at to try and resolve without jumping into new parts.

 

[EWheeler]

The perches will yield about 1"-1.5". Front Range suggested to check caster as well as getting rid of the spring hangers that tuck up tight to the frame. Once I get it back into a shop, will have EVERYTHING looked at to try and resolve without jumping into new parts.

Yes, the caster angle will affect where the tie rod lives in relation to your leaf springs, but I don't agree that the spring hangers will have any affect on the relation ship between the tie rod and leaf springs. I know it wont. It would possibly help with drag link and leaf spring issues, but I would start by lowering those leafs as close to the axle OD as physically possible. You can get super aggressive and notch into the housing tubes, but it shouldn't be necessary.

 

[nor_cal_cyclist]

Yes, the caster angle will affect where the tie rod lives in relation to your leaf springs, but I don't agree that the spring hangers will have any affect on the relation ship between the tie rod and leaf springs. I know it wont. It would possibly help with drag link and leaf spring issues, but I would start by lowering those leafs as close to the axle OD as physically possible. You can get super aggressive and notch into the housing tubes, but it shouldn't be necessary.

Whoever takes it on will have the fun in figuring this out. Way beyond my skill set. I'm sure it can be done, and if not, will go with coil-overs.

 

[cruisermatt]

Definitely a poor choice to skip plating the frame where the motor mounts are welded.

Doesn't front range sell low, flat, and high steer arms? Those look like their flat ones? Why not simply swap out for their higher arms? I would still take that 1" out of the spring perch if it doesn't cause an issue with the pumpkin/passenger spring.

You won't really have a completely accurate caster measurement until the truck is completely assembled and springs broken in. Which is why it doesn't really make any sense to have the knuckle balls fully welded on a custom axle under a bare rolling chassis...

 

[EWheeler]

Definitely a poor choice to skip plating the frame where the motor mounts are welded.

Doesn't front range sell low, flat, and high steer arms? Those look like their flat ones? Why not simply swap out for their higher arms? I would still take that 1" out of the spring perch if it doesn't cause an issue with the pumpkin/passenger spring.

You won't really have a completely accurate caster measurement until the truck is completely assembled and springs broken in. Which is why it doesn't really make any sense to have the knuckle balls or spring perches fully welded on a custom axle under a bare rolling chassis...

He has the FJ80 high steer kit, which I don't believe comes with options for arm height like the minitruck high steer options. With that being said, I probably need to walk back on my statement that many trucks setup with leafs using this kit that works. I suspect the FJ80 high steer was really designed to work with a linked suspension so it is possible that making the kit work with leafs could be challenging, or even not possible. There are probably options and solutions to make them work with leafs, though not off the shelf and also options that would probably make most cry that they would never drive a truck with modified steering components.

If lowering the perches doesn't work, you could machine a spacer plate to lift the mounting surfaces and then bore out the original arm so that a nut and socket will fit through. Tig weld the spacer plate to the original arm with a nice partial penetration groove weld around entire perimeter and I would have no concerns on strength.

 

[EWheeler]

@nor cal

Whoever takes it on will have the fun in figuring this out. Way beyond my skill set. I'm sure it can be done, and if not, will go with coil-overs.

If you don't like the cost to link the front, it may be best to sell the front housing to someone looking to link a buggy with toyota stuff using a 9.5" front diff and 80 series outers , and just build a 40 or 60 housing to correct width and use the 6-stud high steer which IS commonly used with leafs in spring over applications. I was going to suggest 4x4 labs high steer arms, but it doesn't look like they offer them any longer.

 

[nor_cal_cyclist]

Definitely a poor choice to skip plating the frame where the motor mounts are welded.

Doesn't front range sell low, flat, and high steer arms? Those look like their flat ones? Why not simply swap out for their higher arms? I would still take that 1" out of the spring perch if it doesn't cause an issue with the pumpkin/passenger spring.

You won't really have a completely accurate caster measurement until the truck is completely assembled and springs broken in. Which is why it doesn't really make any sense to have the knuckle balls fully welded on a custom axle under a bare rolling chassis...

Will have the next shop look at plating the frame at motor mounts.

He has the FJ80 high steer kit, which I don't believe comes with options for arm height like the minitruck high steer options. With that being said, I probably need to walk back on my statement that many trucks setup with leafs using this kit that works. I suspect the FJ80 high steer was really designed to work with a linked suspension so it is possible that making the kit work with leafs could be challenging, or even not possible. There are probably options and solutions to make them work with leafs, though not off the shelf and also options that would probably make most cry that they would never drive a truck with modified steering components.

If lowering the perches doesn't work, you could machine a spacer plate to lift the mounting surfaces and then bore out the original arm so that a nut and socket will fit through. Tig weld the spacer plate to the original arm with a nice partial penetration groove weld around entire perimeter and I would have no concerns on strength.

The spacer plate between another set of steering arms was suggested (sounded about like the old "rabbit ear" arm Danny Warden used to make). Was dealing with a few other issues and wasn't sure about the solution...my indecision combined with more than a few issues with the build resulted the truck coming home "in pieces."

@nor cal

If you don't like the cost to link the front, it may be best to sell the front housing to someone looking to link a buggy with toyota stuff using a 9.5" front diff and 80 series outers , and just build a 40 or 60 housing to correct width and use the 6-stud high steer which IS commonly used with leafs in spring over applications. I was going to suggest 4x4 labs high steer arms, but it doesn't look like they offer them any longer.

Going to discuss the cost and associated benefits for linking the front (and possibly rear). Goal is a road/highway safe (and predictable) truck with rock crawling ability (Rubicon/Fordyce/Moab - not planning to rock race the Hammers or Anaconda). Bottomline - it's a bucket list build and hoping for something that looks like it just rolled off the showroom floor, but ready for trails and off-road exploring.

 

[EWheeler]

Will have the next shop look at plating the frame at motor mounts.



The spacer plate between another set of steering arms was suggested (sounded about like the old "rabbit ear" arm Danny Warden used to make). Was dealing with a few other issues and wasn't sure about the solution...my indecision combined with more than a few issues with the build resulted the truck coming home "in pieces."



Going to discuss the cost and associated benefits for linking the front (and possibly rear). Goal is a road/highway safe (and predictable) truck with rock crawling ability (Rubicon/Fordyce/Moab - not planning to rock race the Hammers or Anaconda). Bottomline - it's a bucket list build and hoping for something that looks like it just rolled off the showroom floor, but ready for trails and off-road exploring.

Good luck with your build, I hope it comes out as you envisioned. If you care to take suggestions, my #1 landcruiser builder choice would be Don at FC Fabrications in Stockton. I think he shares shop space with Georg at Valley Hybrids, or at least did at one time. His work is 2nd to none and you can have zero reservations that things will be done right and work 100% when you pick it up. He may have a backlog though.....

 

[cruisermatt]

Going to discuss the cost and associated benefits for linking the front (and possibly rear). Goal is a road/highway safe (and predictable) truck with rock crawling ability (Rubicon/Fordyce/Moab - not planning to rock race the Hammers or Anaconda). Bottomline - it's a bucket list build and hoping for something that looks like it just rolled off the showroom floor, but ready for trails and off-road exploring.

I set up my Fj62 with the same goals but on a much tighter college budget, it does that very well (Daily driver, driven approx 80k road miles since I did the big build up with LS, SOA etc) with leafs with a very similar setup up front, frenched shackle reversal with longer springs. It took a little fine tuning but it has been working great for years. The key is getting it nice and low where you can.
You definitely do not HAVE to link it to accomplish all that. If you want to that is a different story. That steering clearance issue certainly would not dictate it. Something like what Evan suggested would work fine.
My right side motor mount ripped off the frame on Rubicon in 2020... because I didn't plate it. The side of the frame rail will just rip right off.

If lowering the perches doesn't work, you could machine a spacer plate to lift the mounting surfaces and then bore out the original arm so that a nut and socket will fit through. Tig weld the spacer plate to the original arm with a nice partial penetration groove weld around entire perimeter and I would have no concerns on strength.

Something like this ^ would work fine. Any good motorsports/offroad fab shop should be able to do a competent job of that.

 

[Paul]

Take a look at Trail Gear or Yotamasters, maybe Front Range. They make step up high steer arms. Not sure it they have them for your setup. Pm me and will send you some photos of my SOA front 40 axle setup.

 

[Paul]

Here you go.