DJ's TJ: Low and Slow

Because I cut out the grill for the frame rails I had to remove the rubber bushings holding the grill up. So I built these mounts to hard mount the grill off of the radiator hoop. This also allowed me to push the bottom of the grill back slightly to make more room for the winch.







Here it is all painted with more Steelit. Aint she purdy? Note the small gusset on the hoop I was using as mockup to see what looked good. Another reason why Steelit is so nice to use.










A little off topic but while I was out I ran into a guy that was having an old willys flat fender built for him that also needed a cage built, so I stepped up to the task and achieved my first customer.

Ok so front frame section is burned in. Now I can place the axle underneath and build my link mounts.
The first thing I did was take measurements and figure out what my link geometry would be. Sorry, I don't have a screenshot of my 4link calculator numbers. If you don't know what the Triaged 4link calculator is please do yourself a favor and look into it. You'll need to spend a lot of time researching what antisquat, antidive, roll center height, roll axis angle and instant center are because all of this is VERY VERY important and it determines how your rig handles in different situations. Do not overlook this if you're building your own suspension. Even if you installed a kit you bought online you should input your numbers into the calculator just to see what they are. If you're building suspension from scratch input your numbers into the calculator in relation to the limitations of your rig. If any of this is confusing let me know and I can provide links to information.

Because I don't have a picture of my geometry I'll type in what I built in the calculator. I used my same Clayton links that I had in the jeep before I removed the axle so the link lengths stayed the same. This made it easy to figure out placement of each link tab. At least 10" of vertical separation at the axle because I have 40" tires (or 25% of tire diameter) is a must. After establishing where my axle tabs would be I figured out what antidive number I can get away with in relation to the placement of the frame tabs. So here's what I had.
AntiDive- 106.36% (aimed for around 100%)
Roll Axis- -3.89 degrees (aim for 0 or less)
Roll Center Height- 28.78" (The higher the better. Axle side track bar height plays a big roll here. The higher and flatter the trackbar the better.)
Instant Center X-Axis- 57.02"
Instant Center Z-Axis- 19.29"

I was real happy with these numbers so I placed my link tabs where I placed them in the calculator and this how it all looked. This should be full bump/droop according to measurements of 16" travel shock.










As stated in an earlier post I knew this would be a limiting factor at full bump. Instead of shortening the lower links or lowering the frame side mounts I lowered the axle side mounts to give me more uptravel of the axle. This took my axle separation from 10" to 11" but allowed my axle to travel another couple inches higher. My lower link tabs hang down a little lower than I wanted but more uptravel is a damn good tradeoff in my opinion.












Everything cycled very well and I was beyond happy with how everything looked. As you can see I also have my steering box mocked up in place to check clearances, I'll post more about that soon.
But there was a big problem. My driveshaft would definitely contact the upper link when the driver side was at full bump. Building a low COG jeep was starting to show how hard it would be. But not a big deal, this is why we tack our tabs and cycle everything before we burn it all in, right?





The driveshaft looked like it would clear if I shortened the upper link and raised the frame side link tab. This would've placed it out in the open above the frame. So I made this mount. By shortening the upper link by 75% it also allows the axle to maintain the proper caster angle in it's entire travel. Looks like the driveshaft would have plenty of room now. This changes my antidive percentage a little but sometimes sacrifices must be made.









Oh and here's a bracket I made to mount the steering shaft to.





Now that the axle was in place it was time to work on steering..

To mount this '78 bronco steering gear I drilled holes through the frame and welded 3/4"x.120" DOM tube completely through to the other side.





The factory TJ pitman arm is splined the same as the sector shaft on this box but the key on the sector shaft clocks the pitman arm slightly to the driver side. With my slightly dropped pitman arm off my TJ the TRE would contact the diff cover when turned full passenger and the axle was at full bump. I don't have a picture of this unfortunately. I searched all over the place to find a TJ pitman arm that was completely flat so it would clear over the diff cover. All I could find were forums that talked about waggy pitman arms but I couldn't find anyone selling these and even if I did they look very weak. I found some pitman arms online that you drill your own hole for the TRE at whatever length you want but they were pricey and it would still be clocked at to the driver side. I ended up just ordering a ~2006 Ford pitman arm from Amazon for less than $30. It's almost completely flat and it's very beefy.

I cut the splines off of my TJ pitman arm and TIG welded it onto my new one. When I welded it on I clocked it rotationally to the passenger side to prevent the TRE from binding with the enormous amount of down travel my axle now has. I cut a big chamfer into the arm and splined section before welding it to get deep penetration. I also welded some small fishplates on each side to strengthen that weld. This similar to doing a an axle shave where you're welding two dissimilar metals together. It should be preheated to around 350 degrees then slowly cooled but since the piece was hot after doing multiple passes it was good enough. I refrained from welding more plate to the top and bottom of the welds because I wanted my bottom nut to be accessible and I wanted the top to have enough room for a puller. Since this pitman arm was designed for a Ford it had a Ford TRE taper instead of a Chevy taper. I drilled out the tapered hole and welded in a Chevy TRE insert. I ground down the bottom of the arm so that the TRE can bottom out on the tapered insert all the way and clearanced it so it can rotate fully.




Here's a pic of the first root pass. You can see a crack at the top of the weld due to the lack of preheat. It wetted together very well when it was all done.





These are pics taken at a later date when it was painted.




Here you can see it clocked slightly






And this is before paint and the insert welded. The boot is removed from the TRE to see the full flex of the joint. You can see I took off about 3/8" of an inch from the bottom.





Because I went to a flat pitman arm I had to cut out the frame to make room for it to turn passenger. Here it is at full lock and axle at full bump.







I'm not seeing any pictures in my camera roll about my steering shaft connection so I'll explain it. I ordered a joint that is splined for the steering box input shaft on one side and 3/4" D rod on the other. Then just cut down the steering shaft to length and it's good to go. That simple. I'll post more about this later because as of current time I still don't have them connected (I need to port my box for ram assist).

Onto the track bar!

I've had an unpleasant experience with the factory track bar bracket. My dad and I were wheeling at Cleghorn when I came down a hill, driver tire hit a rock at very slow crawling speed and ripped the track bar bracket completely off. The frame had a 5 or 6" hole in it. After some ratchet strap action we were able to get off the trail and get it towed home by AAA. I've seen these factory brackts get ripped off 3 other times by friends I follow on Instagram and it finally happened to me. Even with dana 44s and 37s I learned it's important to plate in the thin factory frame before welding on a fat bracket.
In this case my track bar needs to control a massive dana 60 and 40" tires on heavy beadlocks. I figured adding plate to the 3/16" frame rail would be overkill so I just used 3/8" tabs to mount the track bar on both sides. Using 3/8 tabs is not only very strong and disperses the load but it also prevents the bolt hole from wallowing out as easy and causing death wobble or loose steering. I welded a capture nut for my 3/4" bolt to make future mounting and disassembly easier to get to.
Some pics of the failure:










The new tabs










For the axle side I used the same 3/8" tabs I used on the frame. I mounted this side on top of the axle to help with the roll center height we talked about earlier. And because it's so high, I had to clearance the frame at full bump.

Full bump:




Approximately full droop:

Let's move on to the exciting part!

Since my track bar was in and set to the right length it was time for some shocks! Coilovers were kind of the main plan. Since they use a single mounting point at the top and bottom they make packaging extremely easy. But the biggest selling point of them is that they're tunable and rebuildable. Sure you can buy a set and throw them under your rig but if you want to get the most out of them you need to spend a lot of time tearing them down to mess with the shim stack. The pain of tunability and mixture of different spring rates was a turn off for me.

After doing research on ORI struts my mind was blown and I knew it's what I wanted. ORI's are completely different technology compared to anything else on the market. They're similar to an air shock as they use nitrogen pressure to keep your rig up like a spring but these have something else under they're sleeve. They have two chambers instead of one. The big issues with air shocks and coilovers is that they constantly want to unload. If you look at a jeep with coilovers that's climbing a hill the front of the jeep wants shoot into the air. And if that same jeep was on a side hill, the side toward the top of the hill gets light and wants to extend which causes the jeep to flop. This is because that spring constantly wants to unload all of its mass. If there isn't much weight holding that spring down the next thing you know you're on your side in the mud. With ORI's upper AND lower chamber this prevents this unloading from happening. The pressure in your upper chamber is what lifts the vehicle getting your ride height. Pressure in the lower chamber prevents the strut from wanting to extend without weight, keeping you on your tires. And it's all tunable pretty much ON THE FLY by nitrogen through valve stems on the outside of the strut. No need to take the shock apart to change shim stacks like a coilover. Also there's an external rebound adjustment on the lower part of the strut so the entire design is easily tunable. You can also tune the bottom chamber stiff enough that a swaybar isn't needed.. And if that wasn't enough, they also have internal hydraulic bump stops and are built strong enough to rest the weight of the axle on down travel so if you don't intend to fly through the desert on whoops then you don't need limit straps or bump stops either. And of course they're completely rebuildable. Even if it's not your thing I suggest watching some short course rock crawling competitions on youtube. You'll see guys with coilovers and some with ORIs and you'll see how different their rigs react. I don't work for them, I rpomise

There's one problem with choosing ORI's and that's the wait time. Since the planned-demic they've been at least 12-18 month wait time from when you place your order. I got lucky and found that Filthy Motorsports orders them a few at a time so I was able to get a set from them and had them at my door within a few days. I got 4x 16" 2020 struts. The 2020 struts are what you want, the pre2020 models had a slightly different design. I paid $1250 each strut plus ~$320 for a nitrogen tank plus $210 for a dual fill kit.

It's time for some shock hoops!

Starting at full bump I used the same 1.75x.120 DOM I took the tube from just behind the grill to just behind the frame fish plate. the top of the hoops clear the hood by about 1/2". I was pretty happy I was able to keep it below the hood for such a low COG build. I used some shock tabs I had laying around to mount the struts to the hoops. I left the upper tabs outboard a bit to help clear the frame when the axle was at full passenger droop since the short trackbar swings the axle to the driver side so much.













For the axle side I placed a plate on top of my link bracket and built some tabs off of it. It's important to mount the struts as wide on the axle as possible.

It was time to pull the axle out again to finish weld, paint, regear and assembly.













I called my dad over to help with setting up the gears. We had a hell of a time mating these gears together with the Detroit locker. After a while we realized what was going on. The locker I had was a 4.88 and down which means it didn't work with my thick gears. It was mistake at the G2 booth at the offroad expo when I bought these. Oh well, ordered another gear set from Yukon from ECGS.







Here we are setting up the new Yukon THIN gears. We used setup bearings my dad made a while ago. Unfortunately after we set up the proper backlash and pinion preload and installed the real pinion bearing and pinion nut our backlash and preload were a little off. We've never had such a headache installing gears before this. After a bunch of frustration and a couple of weekends we were able to get it set up properly. The yellow gear-marking compound is the final pattern and we had .0065" of backlash. Perfect!

Since the axle was out of the way I can start to figure out my radiator situation. I left my track bar mounted so I can see how much room I had for a radiator and it wasn't much. With the track bar being so high on the frame I only had 16" of vertical clearance between the top of the track bar and the front/bottom of the hood and 24"of horizontal clearance between my steering box and AC lines. This is the radiator I went with: https://www.summitracing.com/parts/gri-1-26201-ts Griffin Universal Fit Radiators 1-26201-TS

The inlet and outlet are on the same sides but they're a little different in size. I got the one with the transmission cooler because the OEM rad had an internal trans cooler. This was a referral to me from someone that had an LS in his TJ. If it can cool his LS then it should cool my 4.0.

After getting it and seeing that the trans cooler is just a small copper tube inside of the cool-side tank I decided just to use a remote trans cooler instead. The "trans cooler" that's built into the rad is more of a temp regulator instead of a cooler.

I mocked up the new radiator and quickly realized how little room I had. I like the reliability of OEM clutch fans but there just wasn't room so I had to remove it and go the electric fan route. I designed an electric fan shroud in CAD but I'll get into that at a later time.

With the clutch fan removed I still didn't have enough room for my rad and fan shroud soooo the AC had to go too
I usually drive to the trail without a top and doors anyway so I wasn't going to miss it. I removed the condenser, compressor and all of the AC lines. If anyone needs a COMPLETE air conditioner setup let me know. I also have the OEM radiator and clutch fan I'll never use.

Now that everything was out of the way I finally had the room I needed. I tried fitting the rad at different angles to see where it was happiest. I didn't like all of the room inside of the grill that wasn't being used that the condenser used to hide. The radiator told me it wanted to live in that little space so I obliged. With it inside the grill I can angle the top back to make more room for the rad cap. With it angled I noticed it would have even more room to move around if the grill was slightly cut. Since this was an aluminum radiator it needed plenty of movement for when the frame flexes. So out with the grill and onto the table for a haircut.








After cutting a little off the top it just started getting out of hand. The more I placed it into the grill the more room I wanted it to have to flex. Pretty soon it turned into this...










Cutting the entire bottom of the grill opened up so many opportunities. This allowed the rad to sit low, in front of the track bar and gave more head room for the rad cap to clear the hood. The bottom of the grill also sat under my bumper which got in the way of my steering. Cutting this out should allow me to run my tie rod ON TOP of my high steer arms never to be contacted by a rock. I also no longer needed the structural integrity of this grill since it's hard mounted on both sides. It's pretty much a radiator protector and headlight housing at this point.

I've since cut a little more on the sides of the grill from the pictures above so yes, the rad has more room than what you see.

The pictures below are about where the radiator will ultimately sit. Disregard the fan shroud placement.









oh... and now that the bottom of the grill is gone I had room to place a crossmember between the frame rails, just behind the bumper. I used a piece of 1.75x.120 DOM for this. Now the bumper isn't the only thing preventing my frame from flexing. And it gave me a place to weld some radiator mounts to. Win win!

Below you can see the crossmember

DylanM345 said:

Subbed. This is fuckin siiiick. Very impressive fab work. This rig is gonna be a beast

Click to expand...

THANK YOU! My heart and soul has been going into this project and I'm absolutely stoked to call it mine. Stay tuned, we aren't even up to date on this yet

Alright I'm on a roll, let's keep this going!

I picked up these tube couplers from Barnes4wd. https://barnes4wd.com/products/1-3-4-interlocking-tube-coupling?_pos=33&_sid=52c7017d4&_ss=r
TMR Customs also makes very similar ones and at the time of writing this they just released a stubby version the other day. I'm using these for my engine cross-support. For this I bent some tube after the couplers and left some room to add some gussets between the non removable tube and the shock hoop.










After I built this cross support I built some gussets out of 3/16" to spread the load of the shock hoops.
Wow the giant pictures on this forum really show off the imperfections. Just look passed the ugly welds






Also added a tube from the hoop to the frame to strengthen this section where the frame is cut out.






Here's where I realized I made a small mistake. This was my first time using these tube couplers and as with everything in fabrication/welding certain steps must be taken in a certain order otherwise major warping occurs. Since I added gussets after building my engine cross-support it warped my shock hoops so much that my cross-support wouldn't line up anymore. I used a high lift jack to spread the shock hoops apart just enough to get it perfect but nothing was working. I ended up cutting my support right in the middle so I can line it up correctly. Check out how much heat can cause so much warpage.




I was able to straighten it all out and weld it together so that it lines up correctly.
After this I welded some lower radiator mounts to the crossmember, welded on some tube caps on the bottom of the shock hoops and... paint, paint and more paint!




















I painted my control arms and steering links and cleaned/greased my Johnny joints.
I installed the high steer arms, assembled the hub assemblies and bolted the wheel/tires on for the fist time.
I threw it all under the jeep, took a step back and probably shed a few tears...













There was still a ton of work to do but I can finally see what I've been working so hard for. I sat in a chair staring at the same view above for an hour with a big smile on my face.

Let's continue.

I designed some 3/16" gussets in CAD and had them cut by SendCutSend. These will be placed between the shock hoop and engine support. I designed these with a 3.5" hole in the center, scroll down to see why.




Let's talk about steering for a sec. The bolt on steering upgrade for the TJs is replacing the steering pump with one from a WJ since It outputs more pressure. I knew this is what I wanted to do.

With this I had to think about what kind of power steering lines I wanted to use since I'm using a bronco steering box that takes different sized ports. If I got custom lines built at a local shop then I'd have to get at least 2 of each made in case I lose a line on the trail. If for some reason that spare line gave out I'd be in bad shape so I decided to go the AN route. This way I can bring extra AN fittings and hose on the trail and I'd know how to build it myself with no special tools needed.

The issue with using AN lines in this case is the return from the steering box to the power steering reservoir. The TJ and WJ reservoir connects directly to the pump through an orifice and it's made of plastic. There wouldn't be a reliable way of connecting an AN fitting to the plastic reservoir. I could have used a 5/8" rubber hose to the reservoir from an AN hose barb fitting but I was already set on the idea of going the remote reservoir route. Locating a remote reservoir to the frame and away from the engine prevents engine vibrations from introducing cavitation to the pump.

I picked up some 3.5x.120" aluminum round tube to build myself a custom remote reservoir. I hopped onto Fusion and designed a top and bottom cap and a baffle to help prevent air bubbles from forming from road vibrations. I also designed a mount that will weld to the outside of the tube and use 1/4-20s to mount to the gusset. The top mount is just the same dxf file as the bottom cap but it has a hole in the center to fit a Meziere Weld-In Cap and Bung Assemblies PN6500. After a few days another beautiful SendCutSend.com order arrived.

Time to make a resy!

For this welding process I'm using GTAW (TIG). I got my aluminum certification in this years ago and I definitely don't practice this enough anymore but it's a blast to weld!

I started by cutting the tube to 5 1/2" long. Should be plenty deep enough to hold the steering fluid.
Here's the baffle I made. FIDI is a name my dad and I came up with that has a secret backstory to. I'll be incorporating this in a few locations on this jeep. We aren't ready to release the details of this yet so I won't go into it now. This baffle sits close to the top and will act as my fill mark.





The top and bottom cap are to the left.






Once the baffle was in I welded the bottom cap on.











For the inlet and return on the resi I used -8 AN weld bungs.









After it was all welded I sanded it all down with a tube polisher machine. I didn't want this thing super shiny so I left it at that.

And here it is bolted in and both gussets welded in place. The passenger side gusset will house a radiator overflow tank that I'll build later.














So because I'll be using a remote resy for a WJ steering pump it's a little tricky figuring out what to do for the return side since it has an open orifice for the factory reservoir to mount to. There's a guy on Youtube that drilled and tapped this orifice so that he can thread an NPT fitting into. Here's the link to that video if anyone's interested Since the orifice isn't very deep you have to cut the NPT tap in half to get the proper thread engagement.

I figured since the pump is aluminum why not just weld a bung to it instead. I used a slightly different weld bung for this since the orifice is 7/8". I used this one here that is meant to sit in a 1" hole. https://www.summitracing.com/parts/FRA-499558 . This allowed me to weld a lap joint instead of trying to burn in the thick wall of the pump to a weird spot on the bung.

Here's what the orifice on the WJ pump looks like.





Before welding this bung on I removed the high pressure side fitting which contains an oring, piston and spring and cleaned the pump the best I could. The trick to welding this is to make sure it never gets hot since I didn't disassemble the entire pump. After tacking the bung in place I welded no more than 1/4" before waiting about 20 minutes to cool before welding another bead so this took a while. Usually when welding cast aluminum you need to create a puddle and let all of the contaminants release before adding your filler metal. Even though this was a used pump and wasn't perfectly clean I never had an issue with it. It welded like butter using 4043 filler.










After the bung was welded on and cool I removed the high pressure side fitting from the TJ pump and installed it on the WJ pump. To convert this fitting to AN fitting you need an M16x1.5 to -6: https://www.summitracing.com/parts/FRA-460616BL

To convert the bronco steering box ports to AN fittings you need a 1/2-20 to -6 on the high pressure side: https://www.summitracing.com/parts/FRA-491955-BL
And a 5/8-18 to -8 on the return side: https://www.summitracing.com/parts/FRA-491949BL

I used pipe dope on these fittings since these replace the inverted flare connections and don't use orings to seal. I tightened them down until they stopped and the aluminum threads started to stretch.




I installed the steering box onto the frame and started building my AN lines. Btw I used Fragola fittings. There are many companies that make AN fittings but it's important to know that every company uses different tolerances. I decided to go with a big name brand. Whatever you use always stick with the same fittings otherwise you take a gamble. Yes they are expensive but you don't want these to fail no matter where you are.

NDSpeed said:

well i definitely clicked the link to see some slammed TJ on 13” spoke rims

but now i see you meant the other low and slow

Click to expand...

Hey who says I'm not building this all for mockup to switch it out to 20s and spinners?

FINALLY this thread is caught up to date. I'd like to thank everyone's patience for putting up with my posts constantly being at the top of this thread section. Posts should be be a little slower from now on but we have a Rubicon trip planned around summer this year and a lot of work still needs to be done.

Last weekend was a big day for the jeep!

I picked up a 60cu nitrogen tank and a dual fill kit and charged the ORIs just enough to lift the jeep off the jack stands. After almost a full year the jeep is officially on it's own weight!!! Damn it feels good!

It's sitting about 1" higher than what I want ride height to be and it still sits lower than the rear which is still on 37s.








Since I ditched the factory rad which housed the trans cooler I ordered a Derale Dual Circuit Fluid Coolers 15301 https://www.summitracing.com/parts/der-15301

This is a dual 8 pass cooler with -8 AN fittings and will be used for my trans and power steering.

I built a mount for it that sandwiches the cooler and is welded to the ABS tray on the drivers side. The idea is to have my 10" fan draw in cold air from outside of the fender. The mount isn't finished but here are pics of where it'll be.












Last night I finished building my tie rod. I'm reusing my dads old tie rod that he switched out for aluminum a while back. It's 1.5x.250" wall DOM just like my track bar and drag link. It's seen it's fair share of rock contact over the years but it'll work great for me. I had to shorten it to fit on my narrower high steer arms so I cut it in half and placed a slug in the center before welding it.

Here's the tie rod on top of my high steer arms. I was hoping it would sit nicely here since my grill was no longer hanging down because damn this thing is out of the way! But with the amount of shaft showing on the struts it looks like I might have to cut my frame to clear at full bump. If I cut the frame in this area it might not be structural enough to see the winching load from the bumper unless I add a lot more material. I could save precious time on this build by mounting the tie rod underneath the high steer arms for now. I'll have to look at it more and make a decision. Thoughts anyone?

NashvilleTJ said:

Why not mount the tie rod underneath the high steer arms? Can you flip the arms?

Also - have you thought about the placement of the drag link? Hard to tell by the oic, but to get it parallel with the track bar, it looks like it may have to mount where the tie rid is now.

Click to expand...

I drilled the taper out of my high steer arms a while ago and installed tapered inserts so that I can have the tie rod on either side of the arm. This is just me being me. Since everything is it out of the way it'd be the best time to do more framework but I can definitely just mount it to the bottom and call it a day.

I already have my drag link built and painted. This might be the only pic I have of it on the arm. It sits on the hole behind the tie rod. Because my trackbar is short and my high steer arms are so wide on the axle my drag link is 11" longer than my track bar. I can mount my drag link below the high steer arm to keep it parallel but it's still gonna be too long to prevent flex steer. But honestly I feel like flex steer isn't that big of a deal because this jeep will only see slow crawling on the rocks, and how big of a dip will it see on the road to where I'm going fast enough for it to matter, you know?