Photon (The Light Hunter) Build Thread

It's been quite awhile since I've updated this build thread, a few things worked on here and there and certainly not at the same rate (or quantity) as when I first started building Photon out. Nevertheless it's been more about performing routine maintenance and hitting some small trails in my area...never got out to the desert this past summer so I'm bummed about that.

So just a maintenance tidbit here, some small mods there...I'll fill in all of the other things I've done to Photon shortly.

But first a simple mod...

9/7/25 Photon Get New Tailights.
Got a set of these Nomad Tail Lights to try out. The fit was surprisingly good and none of the dangling DC supply bricks that comes with the other brands of taillights. These are fully integrated assemblies so just a socket wrench and 10 minutes to install.



Before:


After:


Essentially like many other retro assemblies, yeah they have that (to me) annoying startup sequence but they do produce ample illumination as well as having, I think, a unique side marker for added visibility.

 

Oct 3, 2025 Cabin (filter) Refresh.

I began noticing that the airflow from the cabin vents have been slowly decreasing so I knew it was time to replace the cabin air filter. Its only been a few months but the mountains can be a dusty place so...


*sigh*. That orange fluff got me really concerned, turns out that little turd was gnawing away at the firewall insulation blanket! I forgot to take a pic back then so maybe tomorrow if I remember (got a glass replacement appt to get to!)

I did stuff one of these peppermint packs between the underside of the filter and fan box, haven't checked yet so another thing to check tomorrow.


I did try something unusual in the hopes I can further deter rodents...I had a can of this laying around from when I was doing some anti-corrosion treatment on the frame. I remember it has a bad smell and thoroughly 'wets' all metal surfaces so I sprayed it all over and around the passenger side from the LCA on up and along the firewall and wheel well leading up to the cabin air intake. I'll have to check those areas out tomorrow as well...wonder if I'll see any paw prints?

 

Sorry to be bouncing around right now, but this week has been quite the awakening regarding tires. Prior to today I was noticing that Photons tires were developing (and quite rapidly) cracks in- between the tread blocks and on Monday, after having driven a good 3 hrs the tires quickly and without warning developed a significant 'shimmy'. Leading up to this I was noticing an increase in road noise to the point I began wondering if either my wheel bearings or the rear diff was starting to go. So today (1/29/26), two years and 30,635 miles later it was time to retire the Baja Bosses. Even though there was a good 0.15 nom tread remaining (maybe half that to the wear bars) the shimmy told me it was the beginning of tread separation happening and I'm sure the added static weight that Photons been carrying around had a role in all of this.

So enter the long mulled over quandary and ultimately I decided to give the Toyo Open Country ATIIIs a shot. My good friend whom has been running these on his RAM1500 swears by them (I'm considering weight carrying/durability here) and I've ridden with him over various terrain including winter ice and snow and am very impressed by them.

The real quandary is size, Ive been perfectly fine running the stock 265/70 size and did not feel a need to go wider as one of my beliefs is that a wider tire (like a 285) takes a bit more steering effort than a stock width and from past experience I've had issues with my old pathfinder when I upped the tire width. I needed to install a steering damper or face premature wear out of the steering gearbox, another was premature wear out of the pitman arms spline shaft interface and pretty much everything else in the steering/front end. So I have a dislike for wider tires just for that alone as well as I would like to avoid premature wear out of Photons steering rack, tie rods, etc.

So, for what it's worth I ended up ordering and installing a set of 255/80s, yep, tall skinnys. First drive I already can feel the steering is lighter but also the taller sidewall has considerably more flex (granted the tires were only inflated to 45 psig.) I drove about 20 miles then returned to the shop and had them up the pressures to 55, the next drive the sidewall flex was noticeable reduced and I'm thinking of upping the pressures another 5-10 psig when I head out for my return 3-hour drive across the state.

Even though Photon gained less than an inch of added height I still smackered my shin when I climbed in for the first time.




I'm glad that these tires only weigh an additional 6 lbs/tire more than the Baja Bosses so hopefully I won't be taking an appreciable hit on MPGs. We'll see...

 

W.I.P.

Designed up a simple cover for the SSC1s from last year and since I have a pair of SSC2s thought I’d mock up a pair of covers for those as well.

 

2/20/26 - Rear Suspension Linkage and Geometry.

I've been pondering over various rear suspension setups for a good minute now and in particular the Live Axle/Link setup in our 4Runners. Since I've been driving for some time after lifting Photon, I realize her on/off road manners would improve if I just get off my butt and install the Dr KDSS Trackbar Correction Kit that I purchased last summer. Or, perhaps I can make a modest change to the parts of the rear suspension geometry and eliminate the Trackbar altogether.

For what I'm considering I'm sure it won't be as cost effective as just installing the trackbar correction kit and that I'm just being too anal about street/highway handling...and moving up to tall skinnys seemingly hasn't helped 'street' handling as well. So perhaps all of this thinking at present will just end up in the 'thoughts and ideas' notebook never to see the light of day again...

Now the 4Runner's rear suspension is a proven system of four Control Arms/Links (upper and lower), used to limit the rear axle rotation about the long axis and allow for vertical translation/tilt and a Trackbar (Panhard Bar) to limit lateral translation. But why oh why did the Toyota engineers not simply go with a triangulated four-link arrangement and eliminate the Trackbar? All that's needed as far as I can tell is to move the upper links inward along the rear axle, close to the 'pumpkin', move the upper frame tie points outward and toss the trackbar and its associated bracketry.

So this is where my thinking has led me to, I *could* modify the upper link mounts as described earlier and call it done, or, make use of the simple mechanics of a Watts Link. In its simplest form all that's required is to weld on an attachment plate to the rear diff housing, install a pivot arm and second (passenger side) frame tie point and obtain two link bars with ball-rod (aka Heims) ends to tie it altogether.

hmmm...

 

...because to get rid of the track bar they would have needed to use solid joints (heim, etc..) at the frame/axle ends of the triangulated four-link which would not be comfortable for regular street driving, so they needed to use rubber bushings with some give for on-road comfort, which still requires a track bar to keep the axle centered with the additional play from the rubber bushings.

 

There is only one way to find out if you like it or not. Go for it!

 

@ADVENTR you brought up a very good point there and one I was thinking of whether reusing the factory upper links/bushings would suffice since I'm proposing just a geometry change of the upper links... However, now that I look again at the factory 4-link setup I'm beginning to understand why there can be issues down the road when the suspension is cycled and that revolves around the simple fact that the length of the upper vs lower links are different. I read an interesting bit of technical information about the 4-link geometry and this illustration depicts one of the issues with different link lengths. Now the Toyota Engineers had to of accounted for these angle differences (Slip Yoke) and not binding up the universal joint with too high of an angle (which is a far cry less than the CV joints endure with increasing lift heights/suspension droop.)


Source: TRS 4-Link Tech Measurements & Material Selection

So to simplify things it looks like it's either the K.I.S.S. (OEM Trackbar) or just to be 'different', employ an unnecessary mod by the way of a Watts Link.

 

Ha! There you go offering to spend my money (which is in rather short supply nowadays). I can easily get the necessary steel plate to build the pieces for the Watts Link, now if only I had access to an acetylene torch and some welding gear...

 

Back to lighting stuff...

Been pondering over quite a few options for adding ditch lights and some of the commercially available brackets just seemed like one was placing the lights a bit low. To me, it's hard to judge distance/depth with such a flat light angle so I began toying with the idea of a different location. Made some measurements, used a little math and came up with a possible solution, one of the design constraints is that I would be able to remove the lights for security reasons and to be able to do so with just my hands (no tools required.)


Sent the files off to the printer and a few hours later...


Now I need a trip to the hardware store for some fasteners.

 

What if you eliminate the top links entirely, add a leg to the bottom links for a “Y” configuration (at least on one side..) and use a watts link (or a track bar) for lateral bracing? You’d probably want to gusset/strengthen the remaining link mounts. That would keep the pinion pointing closer to the output shaft as the suspension cycles.

 

If I'm understanding you correctly I believe you're referring to a 'Ladder Bar' configuration? Those were popular for street/drag racing where controlling wheel hop was a concern. Apparently Ladder Bars can also limit suspension travel which for on-street performance is not much of a concern but for us folks who go off playing in the dirt I can see Photon's rear end bouncing about uncontrollably.

And yes, there would need to be additional bracing on the forward frame tie in point to handle the additional stress that an upper link would normally be carrying.

As I dive deeper into suspension design I'm becoming aware of some other considerations such as Anti-Squat, Anti-Dive and Roll Center and how those factor in to how a vehicle will behave, for example, under acceleration and braking.

A quick example of the Anti-Squat consideration within three zones of operation (I'll spare the technical aspects of how this is calculated for the moment):

• Anti-squat between 140% and 180% Drag racing on smooth pavement with STIFF shocks (heavy rebound valving.)
• Anti-squat between 110% and 150% Hardcore rock crawling/bouncing (think KOH.)
• Anti-squat between 100% and 130% Soft terrain (mud) racing.

• Anti-squat between 10% and 50% High speed desert racing (Me!)
• Anti-squat between 20% and 80% Open road/rally racing.
• Anti-squat between 70% and 100% Rock crawling and trail running.

• 100% Anti-squat is a good universal default starting point for a multi-purpose vehicle.
• Anti-squat between 80% and 120% Almost every off-road application (excluding desert racing).
• Anti-squat between 80% and 120% works well for almost every street and track application (excluding drag racing).

*This information I garnered from this source

I did a rough series of measurements on Photon's OEM set-up with the 2 1/2" lift and found that at present she's sitting around the 110% margin. This has everything to do with the lower link angle change (increase) so I think when I load her up with gear the COG will raise up thus lowering the margin to just under 100% as well as very slightly decreasing the lower link (and upper) angle.

The only way I can get her numbers down into the 50% or lower bracket would require a drastic change in link length and I'm not going to go down that rabbit hole cause that means Long Travel.

I am actually pleased with Photon's current handling on and off road, getting used to these tall skinnys is another thing...talk about sidewall flex on-street/highway!

 

Yes, ladder bar is a good name for what I mentioned, except a modified ladder bar system can be really good for off road. On a solid axle jeep I had a few years back I ran a system (IronRock Off-road, Critical Link, Jeep was a 2003 WJ) that replaced the 4 link with a longer ladder bar on the drivers side and a simple, longer, lower link on the passenger side. Eliminated one of the control arms. Then a normal track bar. This allows massive articulation without binding up the bushings, and it still provides solid control of axle rotation if built correctly

Side note: The IRO system I bought had a mediocre caster adjustment system. It was easily fixed by getting the adjustment dialed in and supplementing the adjustment bolts with a couple of 1/2” stitch welds. IRO had a much better setup now using 3 separate control arms, it works like a normal 4 link but by having 3 links it solves the articulation binding issue inherent in a conventional ladder bar system, or a lot of 4 links systems.

Not really thinking anyone would build this out, I’m talking about a pretty involved re-engineering of a system that already works really well. Just like the discussion.

 

where you gunna mount these bad boys!?

 

your exactly right, I often see people ditch lights where half the beam is projecting off the hood lol. bugs me, I just added crude nylon spacers (and Rago extension)

 

I'm so used to designing mechanical structures having symmetry that I have a hard time wrapping my brain around a 3-arm configuration! I mean I do (see) understand this is all that would be needed to mitigate axle wrap, could the same be possible by using two (long) lower links out at the ends of the axle and one centered on top of the pumpkin?

Quick question for you related to your comment about binding of the bushings, is this something that can be easily seen without cycling the axle? I appreciate the discussion as it's providing me an opportunity to learn more about suspension!

 

Well I haven't nailed down (yet) if I want to locate them on the vertical rack flanges or onto the actual outer framework. One has a clearance issue between the light housing and vehicle roof and the other is figuring out if I can get rivnuts properly installed onto the 8020-like framework as its a double wall construction with less than 1/4" gap between walls (and the rivnut body is a good 1/2" in length.

 

All projects on hold, got a call from a buddy of mine early this morning asking if I could come give a hand with some downed trees on his property. We had a really 'wet' snowstorm blow through the area a week and a half ago that uprooted six trees, one that took out a corner of his fence line.

Most of the felled trees came down across a small ravine so access was ok but rather steep slope in some places. Was able to hand drag out the smaller branch cuttings but we decided why not put Photon's winch into service here? I can also take the time do so some inspection on the winch rope, check on the remotes battery and a few other safety related things.

Cleared out all of the smaller branches that we could, carried them up the ravine and into the dump trailer! First load is ready to go to the 'organics' reclamation yard.


Now it was time to start yanking out the larger branches and trunks...


Dragging the large branches and trunks out of the ravine sure beats cutting them up down below and hand carrying up that slope!

 

The 3 link thing was hard for me to visualize at first too, I made some very crude models using cardboard control arms, tape, pins as pivots and literally paper towel tubes as the axle. Pinned it all to a cardboard box to represent the chassis. ‘The binding of a ladder bar setup, and a less than perfect 4 link, were obvious as the pivots/pins removed themselves from my cardboard control arms and chassis. The 3 link and the half ladder bar model would articulate freely. That’s what sold me on the IronRock suspension system..

To your question, I think having the 3rd link centered would be ideal for suspension movement and keeping caster consistent, but it would require new pivot bushing locations, and the drivetrain would be fighting for the same space. An offset 3rd link could use the OEM pivot points.

The biggest compromise with the half ladder bar setup is that caster changes drastically depending on which side of the suspension was compressed/extended. I was worried about that, but in practice it wasn’t noticeable.

 

Take a look at Artec industries in the suspension for a JL or Gladiator. They have some pretty good engineering type drawings for a triangulated 4 link on their website. Not sure if it will help or not but I figure more input is better than no input. 1 day that will probably be on my Gladiator and possibly the 4 runner if we decide to go with a solid axle D44 swap front and rear.

 

I appreciate your pointer to that company's product line. While the (basic) foundation of a four-link's operation makes sense to me I feel there are subtleties to some of the geometries involved that aren't apparent in what material I've studied to date. In particular are the two upper link's angles, some designs call for absolute parallelism with the lowers while others have varying amounts of lateral angles...either coming together at a crossmember or towards the pumpkin. Parallel I get since a trackbar is incorporated for lateral control, what I'm trying to wrap my head around is what @Gravel brought up about binding and I feel that it goes hand in hand with what @ADVENTR brought up about the reason for not using hard pivot points.

I'm having difficulty in setting up the 3D model I created as I have the ability to 'animate' the model. What's really cool about iterative design work is that I can have the model detect interferences (i.e. range of motion, rotation, twist, etc.) and I can play 'what if' scenarios in making adjustments to the model until there are no issues for what I want the model to achieve...the darn thing keeps breaking when I give the axle some movement. Better a model than the real thing!

 

Are you factoring in Johnny Joints on the ends? Pretty sure that is what I’ve seen used on most of these setups. That would limit binding, but I don’t know to what exact degree. I’m not the engineer in the family so can’t really help there. If you build it I can drive the hell out of it though!!!

Edit: also consider making the attachment points on the axle as a single piece bridging the differential. This can be bolted into place with a U-bolt and then welded via a slot in the bracket where it meets the tubes for added strength. The closer they are in towards the pumpkin the more articulation it will provide.

 

aw man, the plot thickens…it can never just be easy sometimes

 

So something link this then, yes? (sorry for the crude illustration)


I've looked at Johnny Joints (Core 4x4 offers a weld in one that has a Zerk fitting for easy greasing. Makes the most sense having what looks like decent articulation angles and that it incorporates a 'soft' bushing material...no jarring clunk-clunking!

 

Never is but I like a challenge!

 

highly suggest using the screw in type Johnny Joints with a jam nut. Even when properly maintained Johnny Joints do wear out and need replaced or rebuilt. Not often but eventually. A shop can tap or thread some DOM or whatever you decide to use if you need it.

And yes on the image of the bridged bracket mount. Good idea with the dimple die kind of approach. Probably adds some strength to it.

 

Thank you for the heads-up on using threaded w/Jam nut. I did a quick search for flex joints with bushings and found a number of vendors that sell them along with rebuild kits.

Designing up a suspension set-up is beginning to overwhelm me in that "I have this part done but that now requires this and this requires that..." But who knows what the future for Photon may be!

 

Tell me about it!!! I’m trying to figure out better more capable suspensions for 2 off road vehicles and I’m not even trying to design my own components. There are so many options and combinations out there.