The 4500 MJ Build

[TORX]

It's been a few weeks, and we've been slowly plugging away on the cage. We've tried to keep the notches as tight as possible.

You'll notice all the tube joints have been prepped for tig welding. All the mill scale on the tubes needs to be removed to prevent weld contamination. We grind the inside and outside of all the joints.

Here's basically the main structure for the roll cage. We're pretty happy with the turnout, and the design. Our goal was to design a strong but simple cage (not a bunch of excessive dead tubes), that also flowed well with the lines of the Comanche.

Rather than running a traditional X on the roof, we chose to add our support tubes off the preexisting node intersections. You can follow each tube pretty much from the bottom of the front cowl to the very back.

The front windshield down tubes tie all the way into the frame. These will be our foundation for our front shock hoops.

Top view from the back.

Rear cross brace node. We'll actually be welding this directly to the back of the cab too with a tie in plate.

The rules also state gussets must be ran on all major intersection on the main structure where a single weld failure could jeopardize occupant safety. Aside from the door bars, which we'll add after the interior work is complete, we really only needed to gusset the cowl cross tube. 1.75x.120 was used.

At this point in order to move forward we really needed to pull the cage for final welding.

Hopefully by next weekend we can get it back on for the final time. In the meantime we're working on the fuel cell mount, radiator mount, front shock hoops, and front fender/grill mounting.

 

[ashmanjeepxj]

What the plan for a seat belt bar? Two 45 degree bends and go through the body to the B-pillars?

 

[TORX]

What the plan for a seat belt bar? Two 45 degree bends and go through the body to the B-pillars?

We've talked about running the harness bar off the rear cross brace. Something along the lines of a tube on either side around 30" above the lower cross-member. That should put the harnesses about shoulder level with our tallest drivers. We'll dial that in when we get around to making our seat mounts.

 

[NW-ZJ-SCOTT]

Whatever happened to this thing?

 

[bmikes]

I stole it

 

[TORX]

Whatever happened to this thing?

Few more days, and you'll have an update.

We've slowly been plugging away at it over summer.

The front end has been a total chore on this build. Shock hoops, steering, shock mounts, track bar, etc. None of them want to play nicely with one another. We're not professionals when it comes to this stuff, and it's really been a challenge to work through all the issues that you encounter in a build like this.

None-the-less, we're all still focused on getting this pickup to KOH though.

 

[TORX]

Wow, I'm sadly long overdue for an update on this build. I am pleased to say we've slowly been plugging away at the rig over the summer. Here's what we've been up to.


At the end of June we had just begun tackling the front shock mounts. Our first design consisted of a tube running from our lower dash tubes to the front bumper. This would really strengthen the front end, and tie well into the rest of the cage. Our plan was then to bend a hoop for the shocks, and weld it to the lower tube we had just made. This design probably would have worked, but none of us truly liked it when we mocked it up. You know the feeling you get when you know "that's it!"

So we scrapped design number one, and went with a more traditional shock hoop. This design tied in to where we recessed the tube work inside of the front frame, and would then tie into the lower dash tubes with an additional tube. Here's our first rendition with a roughed in upper mount, and remnants of the old design on the passenger side.

We struggled with the upper mount for awhile. Mostly due to packaging the coilovers during cycling. In our worst case scenario (passenger compressed / driver droop) we have ~.375" between the spring and frame. We also were limited to where we could locate the bottom mount because we were right on the edge of going past vertical with the shocks. Very tight tolerances to work with. One night Winton and I were brainstorming how to make it work, and we had the idea of making two bends at the top instead of one. This would give us more room to mount the two shocks under the hoops, and not have to deal with an offset plate mount. It was around this point we all got the "that's it!" feeling. Both hoops bent up.

The rear of the hoops are plumb with the frame, and the fronts have a seven degree kicker bend to help with shock mounting.

Symmetry, its a good thing.

Maureen supplied us with fresh berry cobbler, oh my.

For our front upper shock mounts we chose to go with a stacked plate design. While some simple tabs would have worked, we all wanted to go the extra bit to make a nice looking upper mount. When your shock mounts extend through the hood, people's eyes tend to go straight to the hoops, and we wanted something we'd be proud of. Each piece being made from .134" plate, which Winton would then TIG together.

Upper mounts tacked in, and shocks installed.

With the shocks on, we cycled the suspension and steering to check for any issues. Issue number one, with the lower mounts moved outward the knuckles now contacted them before full lock.

Winton and I spent a night machining the knuckles on the mill. We'd clearance one spot, only to find contact in another. By the end of the night we had hacked out the center of our lower mounts completely, but we had full steering. You can also see the frame work coming together for our axle side track bar mount.

After conquering our steering battle, we cycled the suspension again only to repeatedly break our tack welds on our lower mounts. After some investigation we discovered we were maxing out the hiems on the shocks during articulation. This was not a happy discovery.

We built both our upper and lower mounts level, but mounted our shocks at an angle, which offset the hiems. During extreme articulation the hiems would then max out and start to pull the mounts apart. Luckily we caught this, because this is how people break shocks. Back to the drawing board (literally).

We knew we'd have to try and neutralize the angle of the hiems on at least one side. We opted to change the lowers since we were really happy with the uppers. Ted had an idea of using tubing for our mounting material. We discussed some ideas on how to make it work, and a few days later we had some pretty trick mounts made. The shocks mount inside 2" ID material, are angled at an eight degree orientation to help neutralize the hiems, use .250 wall DOM to reinforce the bolt holes, and use a single bolt for the two of them.

Cycled the suspension once again, and readied ourselves for the next issue only to find out it all worked beautifully. There's no binding in the shocks, we have full range of travel, and full steering lock to lock. Just goes to show a little patience and persistence pays off.

I walked into the shop one day to the smell of new tires. Winton picked up some "play" tires in the 40x13.50 Goodyear MTR Sticky flavor. They are massive, but looked right at home on this pickup. During races we'll be limited to 37's, but these should work quite well during rec wheeling.

 

[TORX]

Ted and I spent an evening mounting up some mock up 37" tires, and cycled the front to check for cab clearance.

Our lower mounts cut down and gusseted.

Front end is a roller! We mocked up the skins to start thinking about additional tube work.

In between all this work we also finalized our track bar brackets. Our axle side received a speed hole (bolt access hole for our original mount), got boxed in a bit, and is also welded to a 1.25" tube which is welded directly to the axle tube.

With the track bar finalized, we then remade our upper link bracket. It ties in well to the axle truss.

Neutralized our hiem angles.

We also got our steering box mounted with actual bolts, and no longer a c-clamp. With the frame being .375" thick at this location we didn't feel sleeving was necessary. We've since changed our track bar gusset due to spring interference, but it too is now gusseted and boxed in for strength. We're slowly starting to finalize pieces here and there to help move onto the next.

With the front end pretty much being complete aside from a few small things (bumpstops, pitman arm, final welding), we turned our focus to the rear. After learning a few things from our front end, we decided to keep with the theme of the tube mounts and make eight more for the rear. These would allow us to neutralize the shock angles in the heims.

Got our rear lower mounts fine tuned and tacked on. The rear mount sits on the backbone for the rear axle truss, and the front will be welded directly to the tube and then gusseted for strength.

For the upper mounts Winton and I discussed how to mount them without adding a lot of additional tube. We grabbed a piece out of the scrap pile to mock up our height, and ended up liking the design. It ties in nicely with our upper node, and also strengthens the rear span of the 2".

The mounts angle out about 13 degrees and back 15 putting hardly any angle on the hiems at ride height. We'll probably add some plate work for strength, but they turned out pretty sweet.

Should be a full roller come November. Then the pressure is really on. However, we feel like the really time consuming projects should be behind us. From this point we can focus on the smaller projects such as, seat mounts, winch plate, dash, fuel cell, radiator, and the task we're all dreading... wiring.

Stay tuned for updates!

 

[NW-ZJ-SCOTT]

Stay tuned for updates!

:worship:

 

[Demonoid369]

second to last pic, looks like youre using grade 5 bolts on the upper shock mount? planning to use those or go up to grade 8?

 

[98CherokeeSport]

Wow looking awesome! I can't wait to wheel with Ya when it's done!

 

[TORX]

second to last pic, looks like youre using grade 5 bolts on the upper shock mount? planning to use those or go up to grade 8?

They're just for mock up, Larry.

Pretty much when we need a bolt we pillage the bolt bins for something that'll work. We're getting to the point now where we need to start making a list of proper lengths and grades needed. There's a lot of bolts needed in a build like this!

Wow looking awesome! I can't wait to wheel with Ya when it's done!

Thanks, I think we're all pretty anxious to see it out on the trail too. What do you think, hour and a half to run all of Evans?

 

[rockclimber]

probably just what they had lying around in the shop for mock up purposes.

personally, I reccomend F9-11 hardware for shocks.

I really dig those rear shock mounts.

 

[98CherokeeSport]

Thanks, I think we're all pretty anxious to see it out on the trail too. What do you think, hour and a half to run all of Evans?

Im thinking some time trials may be in order:cheers:

 

[ashmanjeepxj]

Are the front bypasses 16in, what is the planned up travel at hide height?
Ive been thinking a lot about tube placement and want to make a different bypass for my front.

I like how your compression tubes are parallel not in series like mine that will give you more bleed and you should not need to drill your plunger.

Looks like you have a long bump stage is that 4in, are you planning to run air bumps?
It looks like the middle of the shock is the transition to your 2nd compression stage. That will work good if you plan your ride height to be 1in taller than half your shock travel.

My front 14s work good with about 8in of up travel I want a new tube placement that will work better at 6.5-7in of up travel. My suspension geometry is much more stable with 7in up vs 8. I think I want my 1st compression tube to end 1.5in past the center of the shock body. 2.5 in till 2nd stage ends and 3in of bump stage. Ill see what Brian thinks of my plans when Im ready to order.

 

[TORX]

Are the front bypasses 16in, what is the planned up travel at hide height?
Ive been thinking a lot about tube placement and want to make a different bypass for my front.

I like how your compression tubes are parallel not in series like mine that will give you more bleed and you should not need to drill your plunger.

Looks like you have a long bump stage is that 4in, are you planning to run air bumps?
It looks like the middle of the shock is the transition to your 2nd compression stage. That will work good if you plan your ride height to be 1in taller than half your shock travel.

My front 14s work good with about 8in of up travel I want a new tube placement that will work better at 6.5-7in of up travel. My suspension geometry is much more stable with 7in up vs 8. I think I want my 1st compression tube to end 1.5in past the center of the shock body. 2.5 in till 2nd stage ends and 3in of bump stage. Ill see what Brian thinks of my plans when Im ready to order.

We're limited to 14" shocks per the 4500 class rules. We're building the rig for 8" of uptravel at ride height, which has been a chore. In addition to the shocks we'll also be running air bumps front and rear. The rear being the 4" flavor, and the front 2" I believe.

Your understanding of the internal workings of the bypasses are far superior than mine. :laugh: However, ADS did talk with Winton about what we were building, and as a result set us up with some very nice shocks for the application. It sounds like they should tune nicely, which is great to hear. I know we're all interested in learning more about them.

That's surprising you're willing to sacrifice some uptravel on your rig. Is that to get the better geometry for crawling? I know you use your rig for rec wheeling too, and would imagine there's a balance.

 

[TORX]

Not much progress over the past month. Winton was busy touring Europe, and I was busy tearing into my own project. However, this past week we got back into the groove. Picking up where we left off our goal was to have a roller by weeks end.

Machining the rear upper shock brackets, because everyone likes machining pictures.

Coilovers and bypasses mounted. This little pickup has quite the suspension under it.

Last task was pressing in some wheel studs, installing the hubs, and mounting our mockup 37"s. The 4500 MJ is a (could be) roller!

We'll now be moving onto the growing list of smaller projects such as finalizing the fuel cell mount, mounting the radiator, and seat brackets. Most of which is already underway.

 

[JENSSEN]

I would love to see some more updates!

I am planning a simular build :cheers:

 

[NW-ZJ-SCOTT]

x2

Best build on all of Naxja right now!

 

[TORX]

We haven't been too productive on the car over the past two months. I've been busy trying to get my own project back on the road, and the other guys have been out of town off and on.

I did cruise over to the shop this week in hopes of getting back in the routine of working on it again. Here's the current status, sitting on it's own weight (mock-up shocks) at pretty much ride height. Radiator is mocked up where we want it, just have to design a shroud/mount. Fuel cell mounting is pretty much complete, and just needs burned in. We cross braced the very rear of the cage, which also gave us a solid platform to mount our spare tire from. It'll mount off a spare hub/spindle.

Inside, Winton's been busy plugging away on the seat mounts. Very tedious project, but it's turning out great. Driver side is built on a sliding rail system for adjustability between different drivers.

Everyone like welding pics.