Builds Machito the LBJ70 (1 Viewer)

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That's first class and "the right way" to do it. A bit of a time saver which may increase your rust protection and longevity of repair. For spots that can't be reached or places out of sight out of mind that you don't want to strip, I had good results on a 71' chevy with some rust out. Interior places you can't get to to strip such as inside rust ed through panels where you have holes in it after you grind the rust off the outside: Put a rust converter such as POR 15 in a pump type garden sprayer and spray it inside the panel to wet down the interior of the body panel this will "convert the rusted surfaces" to a black primable compound. After this I mixed a 50/50 mix of asphalt solvent based roof cement and mineral spirits. I used the garden sprayer again and this spray to heavily coat the interior of rusted out panels. This leaves a thick, durable, slightly soft black tar coating. I drilled several "drain Holes" in the under/back sides of panels to allow water to drain out freely. Also used this method for undercoating and rusty floorboards. Used putty over bondo over "kitty hair" filler. 10 years when I sold the vehicle nothing had bubbled out and all was still solid.
 
Thanks for the support Rob. I like your suggestion, we didn't do that on this build because we were able to access most areas by cutting them open but that's a good approach to getting in to hard-to-reach places.

I didn't take a ton of photos but after a lot of slicing and dicing we loaded up the body and sent it off for sandblasting. At that time we picked up our frame and suspension bits and got to see what we were really working with. Taking inventory after unloading the trailer...

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The damage assessment wasn't horrible but there were a few surprises. As you can see in the pic above we sent out most of the front clip parts along with the frame. The fenders came back revealing a lot of mud had been used to address prior dents and damage. We made a quick decision to pick up a new set from @joekatana since it would be cheaper to replace rather than repair in this case.

For the frame, we were able to see more clearly what we had already identified as trouble spots. The worst of the rust was in the rear around the spring buckets. It looks like mud had just been able to sit in V-notches for years and led to some pretty serious rust. I didn't snap photos of every little bit but here's a good example at the passenger rear spring bucket. You can see the inner wall of the frame rail is gone where the spring bucket intersected it. The shock crossmember also had holes in it from serious rust, water and dirt probably came in through the open end and sat there for years...

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The front of the frame had shown some rust pitting but when the blaster hit it there was a fair bit of metal that came out, leaving a bit of swiss cheese. This was present on both sides, it's kind of a weird spot since there's not much there to hold moisture but clearly something had given the tin worm a place to start...

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We quickly identified the problem spots and then covered the frame in a heavy coat of chassis black to prevent any flash rust. From there, the metal work begins.
 
Just a bit of advice,

POR15 will not adhere correctly unless you use their metal prep and then completely wash it off with water. Don’t let the metal prep dry either and you need it to soak more or less if rust is heavy.

On bare metal POR15 works great but you need to let it flash rust after the wash. It will adhere very well to bare metal if you do this.

Cheers
 
Keeping tabs on this build, as I can see myself doing this swap...

It's not too bad overall if you can handle a little rework on the firewall. Keeping the trans and tcase in the same location simplifies a lot of things as compared to some of the other conversions we've done.
 
Frame repairs aren't glamorous to look at but you can probably guess the drill... cut out offending sections, plate back in with 3/16 or appropriate patch pieces. Front frame horns came first followed by remaking the rear cross beam...

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The rear shock crossmember and spring buckets took a while, the pieces have more shape so forming takes some time. I didn't snap photos of everything but both sides had a fair bit cut out and then patched back in to make them strong again. We added extra weld to beef things up and tried to eliminate any areas where dirt and water could accumulate.

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Did I mention the axles had some structural rust too? The spring perches and bump stop pads had seen better days...

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Using some heavy wall pipe and filler plates we were able to recreate them to look fairly close to stock.

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Once the frame and axle repairs were done we coated everything in another layer of chassis black and prepared for chassis assembly.
 
Any plans for the LJ fenders and core support?? If not I could use them. Thanks
 
It's hard to know where to begin with the metal work in the body on this thing. When the tub came back from blasting we had a few more surprises waiting for us. Starting with the quarter panels, lots of patch work was revealed behind both driver and passenger door....

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We didn't expect this one, but there was work done in the roof as well. This long patch is on the passenger side and was completely buried in filler that had been blended in...

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Same situation on the driver's side just below the side window. They had done another patch and blend job...

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The front of the wheel wells on both sides were pretty rough too. They had been covered in filler and hidden with some undercoating type of material but the sandblaster reveals all...

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So lots of issues to be dealt with. This truck is still better than the LJ but out came the welder and the tools and away we went on repairs.
 
I'll keep this section on metal repair fairly brief, but rest assured a lot of time has been spent bringing this truck back to solid shape. Starting with the supply chain - a care package arrived from @joekatana

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That's new front fenders, a rocker, new rear quarter skins, and good condition grille and marker lights. Joe's been a great help sourcing parts for this truck and helping us resurrect it from a challenging starting point. As for the repairs, we started with the rockers. The passenger side was pretty much a full replacement which also necessitated cutting out a section of the floor which had rotted as well. The outer shell is a new stamping but the inner was ruined too and is NLA. We fabricated that from scratch using 16ga steel, it doesn't have the same stamping contours as a stock panel but it will have to do.

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The floor section was patched in with donor steel from the old LJ body. In a lot of places we've been able to cut small pieces from the LJ and blend them back in the BJ to repair the damage. This truck truly is going to be a combination of two to create one.

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On the driver's side rocker we were able to keep most of the original and just patch in the rear section.

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As you can imagine, there's a lot of time in fitting and blending these patch panels into the originals. Small challenges arise that you wouldn't expect, for example take a look at the photo above and notice the door bumper landing pad which has a raised portion just outside the main jamb. On this side it was in decent enough shape that it was preserved but on the second pic of this post showing the passenger side that was rotten and gone. We had to create a hammer form to replicate that shape and height in the fabricated opening and it's a pretty critical surface since it is where the door rests and will help set the panel alignment. These are the little things people don't often think of that can add up to hours of labor time.
 
On a related note - does anyone have a link to repair manuals for the 1987 LJ70? I checked the sticky and can only find the BJ, much of it is the same but I think some of the wiring sections related to the 2LT are unique.
 
The ewd 168 manuals I have for sale include the LJ7 series
 
Yes sir both 70 series manuals are back in stock

 
The carnage continues...

Here's the left rear quarter behind the wheel. Pretty much swiss cheese.

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None of those inner panels are available so everything was cut out and replaced with 16ga steel. I didn't catch a lot of pictures but it's basically a jigsaw puzzle of small filler panels where we attempt to recreate the factory structure as best we can. The rear surface of that outer wheel well was pretty tricky, the return lip is made separately on a shrinker/stretches then welded to an inner panel that matches the flat surface to create the finished patch. Time consuming for sure.

Here's the passenger side about halfway through the repair, pretty much the same story:

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In preparing the rear quarter skins we cut up the wheel arch to make sure we could get at any rust sandwiched in the wheel lips. On the driver side there was enough that we ended up taking the whole quarter skin off up to just below the body line. On the passenger side we stopped below the fuel door and then did the front section as a separate piece. Fitting the skins is slow work, we spend a lot of time slowly fitting all the edges trying to get the panels to match up as close as possible to stock seams and joints. When its time to weld you have to minimize heat input to the panel to lessen the warping so we use overlapping tack welds done slowly and hammer/dolly each section where we can get access to reduce warpage. All the joints are butt welds, lap joints are a little easier to do but provide a spot where water could once again get in the joint and start a rust spot so we don't use them.

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A million tack welds later and with a fair bit of grinding they start to look like factory again.

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As you guys can tell I don't do a good job keeping up with the forums these days. The truck has come a long way so I'll try to get caught up in a few posts here...

Continuing on the rust repair theme, after the quarters were done we still had to address a lot of smaller trouble areas. The left side window patch was pretty tricky, we cut out the same section from the LJ to act as a donor. It wasn't in great shape either, but with so many complex curves and angles it would be extremely difficult and time consuming to try and recreate this. We sand blasted the LJ piece bare and patched in all the pits and holes with the welder.

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From there we grafted it in to the BJ body...

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Lots of other small areas had to be addressed in a similar manner. The lower corner of the windshield is a common trouble spot due to water being trapped under the gasket. On this one we made a few small patches and welded up the pits and holes. More grinding and finish work to get it in to acceptable condition...

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We did similar work in the roof gutter, on the C-pillars and more. One interesting thing we found were cracks in the body near the body mounts on the firewall. I have a feeling this thing was used hard and/or jumped a few times. There were matching cracks on both sides that we welded up and ground smooth.

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We also knocked out quite a few smaller repairs and patches in the floors again using donor sections from the LJ body. One of the more interesting things to deal with was the roof panel. It appeared that someone had walked on it or some heavy items had been stacked on it because there were a lot of dents and general waves in the roof panel. We briefly considered a roof swap because the LJ roof is actually pretty good, but I thought we could save this one so I started working with some very sophisticated body repair tools to straighten it back out...

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The floor jack actually works well for this, it's not really any different than a porta-power in the sense of using hydraulic force to move large panels and I was able to work the bad areas back up and get the curvature back. After some fine tuning with the hammer and dolly I think it turned out darn good.
 

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