High travel, high clearance & high octane, a streetable adventure LJ story

Over the last 24 hours I cleaned out the front frame section with a wire brush on a grinder, paint remover to get rid of the internal frame coating I previously used, and a rust dissolver to take care of any remaining rust. It takes some time letting these chemicals do their work. I then sprayed in a coat of weld through primer to prevent any new rust from forming before I can paint.

20180602_frame-rust-dissolver.jpg

(Second coat of rust dissolver)

Reading the warning labels on these ranges from "you'll lose years off your life" to "what's remaining of your life will be miserable." ...I opted to use gloves, respirator, and left the garage doors open.
 
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To make the replacement rails I started with 2-1/2"x4" 0.188" wall HRS tubing in 10 foot lengths. I then cut them in half down to 5' which is all I needed per side on my LJ.

20180531_tube-for-frame.jpg


I washed them out in the sun with the pressure washer and soap, and left them to dry for an afternoon.

I decided to place the seam on the tubing at the top so there'd be less surface area for salt and water to latch onto on the bottom.

I wanted to retain as much strength as possible so I took pie wedges out for the bends, and bent the tube. I matched my frame's bends which are 9*. The bends are 30.5" apart from each other. (The early model TJs may be different. I suggest matching your frame and not going off of my measurements.) Getting these wedges cut is the most time consuming step. I used a cut off wheel to grind the pie a little bigger, test the bend, and grind again until I got the angle perfect.

20180602_tubing-cut.jpg


It's important to take the same amount off each side to form an isosceles triangle. Well worth the work to leave one side uncut, but it takes quite a bit longer than a miter cut all the way through.

Next I used a Diablo edge flap disc to bevel the cuts for welding. I highly recommend using it compared to the cut off wheel.

20180602_tubing-bevel.jpg


I used a few clamps to hold the frame in place to prevent the cooling welds from pulling the frame (in some tests I found that the welding process could easily add an extra degree to the angles as they cooled). The factory distance difference between the front and back is ~4.75" per side (9.5" measured across the frame).

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20180602_verify-bend-welding.jpg
 
For the front bend I used an internal fish plate/sleeve with rosette welds ground flush. This will help keep the build looking clean.

I cut the plate out of 3/16" plate 3"x5", stuck it in a vice and a few hits later I had a nice 10* bend it in. By over bending I think I'll be able to get a tighter fit inside the tube when clamped. A few hours before welding, I prepped the fish plates using zinc weld through primer and applied the primer inside the frame where they'd be going. Just an extra step to prevent rust should water ever find it's way between the plates.

When drilling the holes for the rosettes on the frame I used a 1/2" hole and beveled the holes with a 3/4" bit. Even without the bevel, I found while stress testing that the 1/2" hole alone was enough, but the bevel is an easy addition.

20180602_rosette-holes.jpg


I found a deep throat F-clamp on sale for cheap that worked perfect to hold the plate tightly inside the tube for welding.

Half welded, half ground flush:

20180603_rosette.jpg
 
In the rear I couldn't reach an internal plate into the bend so I used one of the external fish plates I had made previously. It's not quite as clean looking, but it's hidden on the inboard side. Again, I applied weld through primer on both sides.

20180603_fishplate.jpg


Look mom, my welds are getting prettier!
 
Instead of using nutserts to hold the skid I decided to improve upon Jeep's design and insert 3/4" OD 0.109" wall DOM tubing through the frame with a weld washer on top so that a 1/2" bolt can slide through with a nut on the top side.

The first hole is centered on the rear bend, the middle is 9-15/16" in front of it, and the front is 7-15/16" in front of that one. They are positioned 1-1/4" in from the outside edge. My white marker went wherever markers go when they die, so you'll have to put up with the notes in blue:

20180602_tj-skid-measurements.jpg


To keep the spacing exactly the same on the top and bottom, I drilled one side, flipped and rotated the frame section in the vice without readjusting the vice position. Just a little trick!

Where the tube comes through on the bottom I beveled the 3/4" holes with a 1" bit so that it could be filled with the weld and ground flush.

I cut the 3/4" DOM tubing a little long at roughly 6" each. I cleaned off the mill scale by chucking them into the drill press and using a strip of sand paper on them.

Weld washers were Blaine's idea and made out of 1/4" plate with a 1-1/2" hole saw, a 3/4" drill bit for the center hole, and tapered with a 1" drill bit so there'd be an area to fill with the weld.

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The tolerances ended up being so tight that the DOM tubing was a press fit into the holes on the frame. A Jeep version of wack-a-mole ensued.

20180526_inserting-skid-mounts.jpg


Here they are after welding:

20180603_skid-mount-welded.jpg


And after grinding and a shot of primer:

20180527_skid-mounts-flush.jpg


After copying the lines where the laser shown from the take off frame rail, and it's ready to go back in the Jeep!
 
I used a combination of clamps, stock skid, and the laser to align the new rail into place. A few tack welds, removing the clamps, and I welded opposing sides to minimize warpage. The driver's side is in!

20180603_frame-rail-clamped.jpg

(If you wrap a tape measure on the front edge of the front control arms it should measure 45" to the center of the rear skid mount.)

20180603_frame-installed.jpg


In the back I will be narrowing the frame to make room for 2.5" coilovers so for now I just clamped the frame to hold it for measuring.
 
Savvy was kind enough to swap my LJ front driver side mid-arm bracket for the TJ version. I'm going to take a slight detour in my build and clean the garage while I wait for that to arrive. Then I'll finish off the mid-arm and body mounts.
 
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If you followed my previous build thread, you'll probably remember that I applied POR-15 on my Jeep body and within a few months a few spots rusted through again. I went back to those areas and now that I have a more powerful air compressor was able to blast through them with my air compressor with a wire brush. I again applied POR-15 and top coated in gray.

20180604_rust-rear-wheelwell.jpg


20180605_por-rear.jpg


I'm debating on what I should do long term on these areas on both sides. While waiting for paint to dry, I was looking at an aluminum Aqualu body and contemplating how I can cut just these sections out and replace. If anybody has experience with either I'd be interested in hearing what you did.

I also hit the spots on the body behind the front fenders:

20180605_por15-front.jpg



holy crap this is impressive. Thanks for posting, keep up the good work!

Haha! Thanks!
 
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All of the body mounts are being raised to remove the "adjustable height" JKS body lift except for the mounts under the grill. For those I replaced the JKS BL with Savvy's aluminum puck in the center and snubber extensions on the sides. The benefit of their design is that it allows for factory amounts of body and frame flex and the center puck torques down to the correct height every time.

20180607_savvy-bl.jpg
 
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Savvy was kind enough to swap my LJ front driver side mid-arm bracket for the TJ version.

Here's the difference between the LJ and TJ version of the Savvy Mid-Arm:

LJ:
20180531_savvy-mid-arm-LJ.jpg


TJ:
20180612_savvy-mid-arm-TJ.jpg


This solves the potential water intrusion issue I mentioned a few posts back.

I sanded the brackets and sprayed a coat of weld through primer on them.
 
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Some of my body mounts are a bit worse for wear so on the 4 rear and the 1 under the grill that all have flat washers I popped out the old crumbly rusted washers and replaced with 2" OD, 1/2" ID, 0.065" thick stainless steel washers (McMaster-Carr #91525A150). To get the thickness right I had to double up on them.

20180612_stainless-steel-washer-bodymount.jpg


Sure beats having to spend the money on new ones!
 
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The mid-arm brackets are welded on the frame side!

20180614_rear-savvy-mid-arm.jpg


I decided to not replace the extra LJ frame stiffener on the driver's side for the reasons mentioned earlier.
 
I replaced the previously raised Poison Spyder body mounts with GenRight's lifted body mounts. They fixture on the frame to take nearly all of the guess work out of positioning the mounts 1.25" higher than factory. Especially after the extensive frame repair, this is a life saver.

It turns out my Poison Spyder mounts weren't installed at the correct height or angle, it could be partially the fault of the JKS body lift having compressed too much too when the height was set. Here's the comparison off the Jeep:

20180602_bodymount-height-difference.jpg


I had to do some trimming where they fixture on the frame in the areas of the mid-arm Cs.

20180614_body-mount-cut-over-midarm.jpg


Regarding the strength difference between the Poison Spyder mounts and the GenRight mounts, I think a lot of times we loose sight of finesse decide that bigger is always better. I think the GenRight mounts will be strong enough to take a few hits, plus the clearance on them is better so they're less likely to hit and hangup on stuff in the first place.

After mounting the tub back on, I noticed that I did in fact "gain" body lift vs the previous combination which had barely left any room for the mid-arm brackets.

20180614_body-mounts-installed.jpg
 
Today was a little of everything kind of day.

To make room for 2.5" coilovers I'm narrowing the frame in the rear. So the gas tank and rear frame section is out!

20180616_rear-frame-removed.jpg


Last year I had run stabilized gas through the engine. Is there anything else I should do now or before starting my engine in another 4-6 months or so? I've heard taking the spark plugs out and fogging before starting can be good?

Mounted up a tire to start getting an idea of how much I'll need to trim.

20180616_37-tire-mounted.jpg


And I started to play around with the 4 link in the rear:

20180616_rear-4link.jpg


With the frame set at approximately ride height it looks like the RJ60 and 37s should clear with around 7" of up travel. Only requiring some minor trimming of the wheel arch to widen it out. Based on very rough measurements anyway.
 
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For the backhalf I decided to go with the kit from 4x4 Outlet (916-704-5446). This narrows the frame to fit under the tub. For the new rails in the rear and bumper I used 2x3" 3/16" wall tubing. Combined with some custom fab and careful placement this is the only kit that I'm aware of that allows for the use of the stock body mount locations. The kit isn't perfect and does have some large gaps. They also include a large oval hole in the center for a sway bar but it ends up right in the path of the upper control arms(???). If I were to do it again I probably would have made something myself. But they'll work just fine and I think they look visually pleasing.

20180623_4x4outlet-backhalf-kit.jpg

(Yes, I know it is upside down in this picture...)

20180623_4x4outlet-backhalf-kit-installed.jpg


It is important to me to keep the factory torque boxes and body supports in tact so the body will not rip apart over time. To do so, I dropped the rear frame rails in to tie into the bumper. I went through several variations of the drop down in the rear and ended up creating it out of miter cut tubing.

20180623_backhalf-dropdown.jpg


20180623_rear-frame-rails.jpg


Rear body mount off bumper:
20180621_rear-body-mount.jpg


For the bumper/rear crossmember I beveled the bottom for some styling. In all at the bumper I gained 2.25" of ground clearance by using 1" shorter tubing vs stock and another 1.25" by deleting the bodylift.

20180621_bumper-tubing-cut.jpg


20180622_bumperr-welded.jpg


Creating the shackle mounts took hours. From now on I would design a bumper to use mounts that I can purchase.
20180621_bumper-shackle-mount.jpg


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20180624_rear-bumper-side.jpg


20180624_backhalf-installed.jpg


20180624_backhalf-installed2.jpg


The bumper used up my welding gas much faster than I expected and when I called my local welding shop to refill they're completely out of C25 and will be for another week. I ended up driving a few hours to get another tank from one of the chains (I found out that luckily they have a local distribute near me, but they were also out of C25 this week). It'll be nice to have tanks from different companies so I'm not relying on the one shop anymore and I can completely run a tank out before filling. At the same time I picked up a bottle of Nitrogen for charging shocks.

I also broke my only hole saw mandril so I wasn't able to finish the middle crossmember. Expect to see more progress on Wednesday once it comes in.

At this point I have everything tacked in and will be sliding it out so I can weld and paint it back at the table.