BJ73 Build (1 Viewer)

[The Eradicator]

I meant to start a build thread on the 73 a while ago, but forgot about it until @joekatana suggested I post one in here. So, let's start with a bit of backstory. In 2016, we imported two 73's from Japan: a clean HZJ73, which we sold, and this BJ, which had a number of mechanical issues. The most apparent of which were the shredded bearings in both diffs and the transfercase, likely due to over-greased slip yokes.

Rather than rebuild the 70 axles, we decided to swap in 80 axles... and go to spring over, 37s, harrop e-lockers, high steer, etc. Cut to early summer 2017, when we finished that project, and here is how it sat:

After wheeling it like this for a while, we weren't happy with the suspension. At a 24" frame height, it was too high. The 70 body just sits too tall to keep a decent COG sprung over, IMO. We also had issues with axle wrap and lack of uptravel.

 

[The Eradicator]

After snapping a rear leaf in Disney, OK earlier this year, we decided to ditch the leaf springs and ordered a 4 link kit from Barnes 4WD. We played with the geometry in the link calculator and tacked in the brackets, then mocked up links out of pvc before cutting 2"x1.5" DOM. For coilover mounting, we copied the setup on Nitro Gear's BJ73 and frenched towers into the frame. The shocks are Fox 12" remote reservoir with 200/250 PAC springs.

 

[GLTHFJ60]

drool

 

[The Eradicator]

Since dad has an aversion to rocks being flung through the wheel wells at the back of his head, I made boxes that seal up the holes in the rear floor while we were waiting for the shocks to arrive. Unfortunately, I did not consider that the reservoir hose would be pointing inward, so I had to cut further into the floor, scrap the old boxes, and make bigger ones .

The old bumpstop extensions and stock bumpstops were repurposed to work with the new location and increased uptravel.

And that pretty much gets us up to date. We still have to finish weld a few things, make new brake lines, and paint, but we are nearing the end of this project and will be starting on the front soon.

 

[SNLC]

Nice!

Had to box in the back floor on a truck I had too. Just to much friggin dust left open.


Cheers

 

[sine80]

Subscribed!

 

[The Eradicator]

Rear end is done. Front is in progress. All leaf spring brackets have been removed from axle and frame, and lower mounts are tacked in.

 

[The Eradicator]

Front end is mostly tacked together. Still need to sort brake lines and bumpstops. Trying to get everything together in time for the Razorback Ramble in June. Frame is sitting at 20.5" with 4.5" of uptravel front and rear. Fenders are going to need some trimming to stuff the 37s. Trying to keep a 70 low and maintain decent uptravel presents some interesting problems. One of which is that the tie rod contacts the pitman arm near full bump. Our solution was to notch the frame and raise the draglink. We tried a flat pitman arm made for minis, but found that, while the spline count is the same, the IFS mini box uses a much steeper taper. We ended up cutting and welding the 80 arm that fits the 70 box perfectly.

 

[Ryan Towry]

looks good! I bet 20.5" will feel night and day different than 24"

 

[joekatana]

Front end is mostly tacked together. Still need to sort brake lines and bumpstops. Trying to get everything together in time for the Razorback Ramble in June. Frame is sitting at 20.5" with 4.5" of uptravel front and rear. Fenders are going to need some trimming to stuff the 37s. Trying to keep a 70 low and maintain decent uptravel presents some interesting problems. One of which is that the tie rod contacts the pitman arm near full bump. Our solution was to notch the frame and raise the draglink. We tried a flat pitman arm made for minis, but found that, while the spline count is the same, the IFS mini box uses a much steeper taper. We ended up cutting and welding the 80 arm that fits the 70 box perfectly.

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Any particular reason for not replacing the steering box with a model that has the pitman facing forward to make space and create less of an angle?

 

[The Eradicator]

Any particular reason for not replacing the steering box with a model that has the pitman facing forward to make space and create less of an angle?

I wasn't aware that front facing boxes were available. Finding one for RHD might be problematic. I'll be interested to see how you address this on your rig.

 

[joekatana]

I wasn't aware that front facing boxes were available. Finding one for RHD might be problematic. I'll be interested to see how you address this on your rig.

I actually have a rhd forward pitman arm box listed in the classifieds here

LJ7x,60 series and 80 series use forward facing pitman arms and are very similar in design and dimensions.

I have to see how much I can move the axle forwards and then I can choose between either the stock box, a 60 series forward with dropped pitman or an 80 series with a regular style pitman.

I would like to go with Hydro assist steering also so I will need to figure out which box works best and what kind of ps pump and where to put it, I don’t think the build in stock 1hz/1hdt pump will be able to move enough fluid for the hydro assist.

 

[Tapage]

I don’t think the build in stock 1hz/1hdt pump will be able to move enough fluid for the hydro assist.

that would depends on the overall shape of your selected pump ( OEM ) and the size ( diameter ) of the piston ..

 

[joekatana]

that would depends on the overall shape of your selected pump ( OEM ) and the size ( diameter ) of the piston ..

Are there upgraded versions available?

 

[SNLC]

Double sheer is great for strong steering.

Any particular reason you didn't use Hellfire knuckles?

Cheers

 

[The Eradicator]

Any particular reason you didn't use Hellfire knuckles?

They weren't available when we were buying parts. HellFire Fab had stopped production and RuffStuff hadn't pickup them up yet.

Paint went on today. Final assembly tomorrow.

 

[Tapage]

Are there upgraded versions available?

pumps .? for 1HZ / 1HD family ..? not that I'm aware of ..

Horacio down here made the local ( you know local labor quality ) experiment to try an adapter to run a PSC pump ( like the one I have in Tencha ) on he's 1HZ with no avail .. but I saw the adapter .. the idea was promising .. nor the execution.

 

[The Eradicator]

Testing at SMORR this weekend. Trails were pretty sloppy. Here are a few pictures. I am uploading a short video to youtube now, and will post it when it is done.

I trimmed 2" from the top and front of the front fenders. Probably should have gone another .25", since the tires did some "self-clearancing." Rear still needs to be trimmed, but that can wait a bit. The ride is much smoother and eliminating axle wrap made a huge difference. The increased uptravel also allows it to hit obstacles much harder and combined with the lower center of gravity, makes carrying a lot of momentum through rough spots feel safer.

I think that the next few projects, in no particular order, will be:

• Trimming rear wheel arches
• Rocker panel chop (like I did to my 4Runner here: 1985 4Runner: 35s, No Lift) and installing rock sliders
• Rear sway bar
• Transfer case skidplate

 

[The Eradicator]

 

[The Eradicator]

With the body acting as the rear bumpstops, it was time for more trimming. I took another 1/2" off of the front fenders and 2 1/4" off the rear quarters. The passenger side already had the rust properly repaired, but the driver side was full of holes covered by filler and fiberglass. The patch panel from @joekatana came in handy for repairing the rust that was left after trimming the top out. Rather than patch up the rusted out rocker panels, I trimmed them up to the doors and capped the bottoms. Aside from being easier and cheaper than keeping the stock rocker, this nets ~ 2 1/2" of clearance under the sliders.