I cut my Tacoma in half.

[TheZenTree]

I bought a 3-linked supercharged dual t-case Tacoma last month that I thought had some moderate frame rust. The frame behind the cab was totally rotted. The frame under the cab is also pretty bad, but that's a future-thezentree problem, not a current-thezentree problem.

So anyway, I started blas..cutting

I've seen some of y'all do some legit fab work, and want some input on what I'm thinking for how to tie the new frame rails (2x4 .120 box tube) I built into the factory frame under the cab.

Pass side frame rail is long, I'll cut it to length eventually.

Current plan is to stab the box tube into the factory frame up against the outer upper corner. It'll go about a foot into the factory frame, and on the outboard side I'll drill two holes just ahead of the cab mount and plug weld (red scribbles) the box tube into the frame, then a big fish plate over that (blue scribble), and I may or may not replace that cab mount (it's not great) and weld that to the fish plate. If not, I'll have to cut a big "U" out of the fish plate to go around the body mount, which seems less ideal than one big plate, but also like a hell of a lot less work.

For the inside, there's a big gap between the inbd side of the box tube and the inside of the frame, and same on the bottom. What I'm thinking is a plate butt welded to the end of the frame, and tapered out to the side of the box tube, same for the bottom. Then a big fish plate over all that.

All the fish plates are 3/16" and will have big holes cut in them for big plug welds across the factory frame and the box tube. I am considering adding a short fish plate on the top (frame to tube) and bottom (frame to taper plate), but there's not much room with the cab where it is.

Y'all see anything dumb about what I've got planned? I mean the structural plan, not the "try to save this rusty shitbox and not put the parts on a clean truck" plan.

 

[frankenyoter]

SEND IT!

 

[gslander]

Raise your fuel tank while you are at it!! The entire project is not hard, just really tedious! I went around the body mount when I did mine, kind of a PITA but so was replacing that body mount! Tag me or shoot me a message if you have any questions along the way!

If you extra hate yourself, cut those rocks out and replace them with 2x6 tube and ditch the sliders.

 

[TheZenTree]

Raise your fuel tank while you are at it!! The entire project is not hard, just really tedious! I went around the body mount when I did mine, kind of a PITA but so was replacing that body mount! Tag me or shoot me a message if you have any questions along the way!

If you extra hate yourself, cut those rocks out and replace them with 2x6 tube and ditch the sliders.

I need to go back and look through your thread to see how you did your fuel tank lift. I sorta remember some bracket you made for the front mount (maybe) but mine just mounts with straps and pins front and rear.

How'd you run that 2x6" tube into the bed past the cab? I'm strongly considering doing that but not sure how to support it between the back of the cab and the rear wheelwell without tying it into the frame, and I'm not sure I want to do that since it's still got rubber cab mounts.

 

[gslander]

I need to go back and look through your thread to see how you did your fuel tank lift. I sorta remember some bracket you made for the front mount (maybe) but mine just mounts with straps and pins front and rear.

How'd you run that 2x6" tube into the bed past the cab? I'm strongly considering doing that but not sure how to support it between the back of the cab and the rear wheelwell without tying it into the frame, and I'm not sure I want to do that since it's still got rubber cab mounts.

It's floating right now, I have a Barnes bushing kit that I will eventually tie it into the frame with some tube. I have beat the piss out of it for a year with no real issues though.

 

[TheZenTree]

That bushing kit is a good idea. Think I'll borrow that haha.

First though is to just get this thing driveable.

 

[gslander]

That bushing kit is a good idea. Think I'll borrow that haha.

First though is to just get this thing driveable.

Yup, that was my goal as well. That turned into a season of wheeling and me scavageing all the tabs and bushing stuff for different projects lol

 

[rodney eppes]

Nice Job! But I'd be moving that cushion that's on the floor at the drivers door. Tan ish color with cotton stuffing; just looking for a Spark!

 

[TheZenTree]

Progress over the last couple days. Frame rails are boxed in and fully welded on both sides, and I got the fish plates cut out tonight. I still need to notch and bend them so they fit a little better, but one step at a time. New bushings for the rear springs showed up today, so I can start mocking up the Barnes spring hangers I got sometime soon. Hopefully

3/16" plate may have been a little overkill...

Plug welds forward of the rear cab mounts, and a giant gaping hole where the frame rotted around the slider frame plate welds:

Frame box plates tacked:

Frame rails boxed and fully welded:

Fish plates (mostly) cut. I forgot I needed to cut some holes for plug welds, so I'll have to go back and do that next time I have a minute to work on this thing.

It's annoying to squeeze between the frame rails and the garage door to get to the driver's side, so all my pics are of the passenger side. That said, I did end up taking the driver's side rear cab mount out and have an OEM replacement sitting on my workbench. The frame where it goes is pretty thin though, and I really want to plate it all the way back over the plug welds I mentioned in my earlier post. The downside is that'll push the centerline of the cab mount probably 1/4" out of alignment with the cab. So, I could either 1. ignore the fact that the frame is tin foil and glue it back on, 2. hack the OEM mount up to try to make it work, or 3. get some box tube and fab my own mount. Option 1 seems appealing because I am lazy, but I will probably regret that.

Anyone have any better ideas?

Also, I've been trying to get ahead of future rust issues by painting the interior of everything I'm welding up with steel-it. I'm sure most of it has burned off at this point but I don't really have any better ideas. Eventually I'll cut drain holes in the new frame rails every couple of feet and coat the inside with that Eastwood internal frame coating. And also not drive this thing in road salt. God I hate that shit...

Nice Job! But I'd be moving that cushion that's on the floor at the drivers door. Tan ish color with cotton stuffing; just looking for a Spark!

Oh yeah, it gets moved a lot. That separates my ass from the cold garage floor when I'm not making sparks.

 

[Monkeynono]

I saw option 1 or 3

 

[paradisePWoffrd]

When you take those fish plates back off for the plug holes, I would suggest to round out the ends. Making the shape more of an oval changes to shear planes for the HAZ, and creates a stronger joint.

 

[gslander]

When you take those fish plates back off for the plug holes, I would suggest to round out the ends. Making the shape more of an oval changes to shear planes for the HAZ, and creates a stronger joint.

This. It also gives you a longer weld, make it look like a bullet

 

[TheZenTree]

Yeah that's a good idea and I'm going to. I really only have like an inch of factory frame behind the cab mounts so I can really only knock the corners off without tapering the plate back behind the main joint, but I can probably squeeze another inch of weld out of doing that. I'll definitely do it on the back end of the plate, and on both ends of the plates at the top of the rear joint (still need to cut those out. If it's not horrific cold on Monday I'll spend a few hours in the garage.

 

[gslander]

Yeah that's a good idea and I'm going to. I really only have like an inch of factory frame behind the cab mounts so I can really only knock the corners off without tapering the plate back behind the main joint, but I can probably squeeze another inch of weld out of doing that. I'll definitely do it on the back end of the plate, and on both ends of the plates at the top of the rear joint (still need to cut those out. If it's not horrific cold on Monday I'll spend a few hours in the garage.

What I did with mine, and I am not a frame engineer so this is only free advice from a random bozo on the internet and build at your own risk, was plate the sides, and tapered the fish plate as much as possible on each end. When I got close to the horse collar I tied it into that, but also left some room to be able to cut it off and reinstall a new one in the future if I had to. I also plated the bottom of the frame and did the same thing, tapered as much as I could.

I also used 3/16 plate as it worked out great on my front frame fish plates.

Again not a frame engineer.

 

[TheZenTree]

YouTube lied to me about how long fabrication takes.

3 of 4 fishplates cut, tapered, and tacked in place. Still need to get the DS outboard plate done.

And then do the other joints.
And get the spring hangers in place
And build crossmembers
And build fuel tank mounts
And…

 

[gslander]

Yea it's pretty tedious

 

[Monkeynono]

View attachment 411222

YouTube lied to me about how long fabrication takes.

3 of 4 fishplates cut, tapered, and tacked in place. Still need to get the DS outboard plate done.

And then do the other joints.
And get the spring hangers in place
And build crossmembers
And build fuel tank mounts
And…

It because you didn't time lapse it...

 

[TheZenTree]

There’s like 40 hours in this picture.

I’m just posting pics at this point because it makes me feel like I’m making progress. And everyone likes pictures, right?

 

[TheZenTree]

Really been working hard on this thing. I mean putting in just tons of hours.

 

[TheZenTree]

I’ve had to travel a lot for work (Montana is badass), so haven’t had much time to work on this lately but I took a half day on Monday when it was 70 and sunny to work on this. Fish plates and body mount are all fully welded.

On to spring hangers next.

 

[TheZenTree]

oh hey.

Fuel tank mounts:

I need help figuring out the rear shackle mount position. The front spring hanger is at the same point in the wheelbase as the stock mount, but it's 1.5-2" higher than factory because of the section height difference between the 2x4" box tube and the 5.5" factory frame. Same springs, same length shackles.

I started with the factory horizontal spacing (1335mm). Jacking the frame up until the tires are totally hanging gets me this:

And weight (bare frame, no fuel tank or bed ...or cargo) on the wheels:

So I moved the shackle hangers forward ~6” so the shackles were at 3-4 degrees from vertical with the wheels in the air, but that resulted in this with just the weight of the bare frame on the rear axle:

Splitting the difference will still invert the shackle with the wheels off the ground, but the shackle goes to about 30-45 degrees with weight on the wheels and four very bald 37s piled on the frame on half a sheet of OSB.

what do.

Are longer shackles a viable option? I don't even care if its squatted a little right now, just want it to be able to carry its own weight at this point.