'02 cracked rear framerails

Friends/clients noticed this on their '02. I can tell you there's virtually no rust on this frame so it's not the common Taco rot issues.

Things don't rust much here. That said I'm sure others have seen this failure as well.

Both left and right:

 

Once hanging on the lift the cracks of course closed up. It was actually amusing to watch the bed "droop" and swing away from the cab as it unweighted.

First thing I did was grind a small V in the cracks, weld up and then grind down. I didn't get too worried about making this step great because it won't actually add much strength

I also didn't like fighting the bed mount so I removed some of it.

You can see on the driver side I elevated a wire loom with 1" sq (air is the best insulator) and threw a spare glove around the filler neck - I hate performing hot works near fuel tanks

 

Damn. That's impressive and sad at the same time. Are you going to try repairing it or replace the frame? It'd be a good candidate to build a new frame from that point rearward considering the cracks are the same spot on both sides.

Edit - NM, I see you are still updating the thread with the repair work.

 

Nice work. A couple of fish plates on that would strengthen it considerably.
Just a thought.

 

I had some 4x3x1/4 angle laying around that was just about perfect for what I was doing. Specifically, if you grind to the top of the weird window in the bed mount the 4" leg fits perfectly.

I wasnt too worried about getting on top or even very near the top of the framerail because that's not where most of your load is, and it hadn't yet separated there -- if it had the frame would have literally been in 2 pieces

Here's basically what my fish plates wound up looking like, 7" OAL (completely arbitrary, probably should have gone longer)

 

Oops...obviously you've already thought about plates. Carry on sir.

 

Here's the plates in place, and I replaced the removed bed mount leg with 1" angle (again, it was here, flat bar would be fine, too)

I should say I'm not posting to say "look at my awesome welds"....'cause they're not. On my best day I'm a mediocre welder, but my stuff holds together. I've actually been welding and fabbing for ~15 years but some of it is that I just don't have the natural ability -- we all have our strengths and weaknesses -- and some of it of course is just not enough consistent, daily repetition and practice

Also apologies for the shadowed pics - apparently photography is another of my not-so-great skills!

 

Actually I think those are good looking welds. Nice work...don't think that's going anywhere.
Cheers

 

Now on the left the fuel tank is in the way, but on the right you can see Toy tried to box this frame but came up short.

The cracks in Post 1 actually started right where this inner plate curves IN - by design there's a small gap with no factory weld

But also I found it fascinating to see three cracks radiating from this hole on the inner wall.

 

What's the use history of this truck? Extended cab, double cab or regular? Just curious since you said the frame is virtually rust free and the pics appear to confirm your finding.

 

Oh yeah, everything I do is "gud nuf", just not worthy of bragging rights.

If they ever manage to get this to tear apart....well, you've got bigger concerns 'cause you're likely dead or fatally injured.

 

It's an extra cab, 4x4, mostly base model, 2.7/manual.

They said they think it was a landscaping truck BUT they bought it in '05....my position is that even IF it saw hard use from new in '02 to their purchase in '05 that's not sufficient to cause this sort of failure 14 years later.

Also they occasionally hauled water in it when their 1/2 ton truck was down. EVERYONE hauls water here. But the last time that was done was 2 years ago and it was not regular use this way.

No, I don't know how much water but I know she'd only fill her tank halfway when she had to use the Taco - so she understood it's not a full-size truck -- at least to some degree.

Again my position is that even IF overloaded a frame should not be the first thing to fail. Springs, axles, spring hangers etc should all go first.

Basically, I feel Toy simply under-built these frames and the history of frame problems for first gens seems to support that

 

There’s a few companies that make frame reinforcement plates for the rear frame. So far so good on mine, but I may want to have some burnt in for good measure...

 

I threw an 1/8" thick plate over that inner hole but I think it's mostly a feel-good measure and not adding much actual strength. It is, however, tied into my fish plate at the bottom.

Had to hook the gun over the muffler and stand on my toes for the top LOL (top of photo)

 

that's definitely a weird break even if overloaded. normally you would want to see it warp or deform just not crack completely.

good work so far, at least it's welded to use

 

Nice work

 

I think it is called "fatigue crack" - result of repeating overloading, not a single event. Once it starts there is no need to overload it anymore - the crack will grow bigger and bigger every day.

Unfortunately Tacoma is not a "working truck" - it is "pretending" to be a truck - hence towing and loading capacity. It was oriented into a comfort driving for highway use. They are excellent off road (for fun) but not much a "farm truck".