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-   -   FJ40 Body resto (http://www.risingsun4x4club.org/forum2/showthread.php?t=8575)

Rzeppa 11-24-2008 07:55 PM

FJ40 Body resto
 
This question is directed in particular to those on this forum who have done FJ40 restos.

In VERY closely examining how FJ40 bodies are put together, and in particular the b-pillars, quarter panels and wheel wells, I am fairly puzzled at the factory's design. Why are the quarter panels bolted to the b-pillars, and sealed with seam sealer, and then the top of the lip is welded to the top of the b-pillar? Why is there this mix and match of bolting, welding and seam-sealing? The places where the front of the rockers bolt to the a-pillars is a similar mystery. Why is it bolted AND welded? Why not just one or the other?

Why are the quarter panels not welded, bolted OR seam-sealed to the "box section" of at the ends where the floor pans attach to the mid-bed? I'm REALLY tempted to weld them there.

It is tempting for me to say "screw all this bolting and seam sealing, just weld everything!". And then fill with body filler or seam sealer as appropriate. But there must have been a reason. Anybody know?

An important tip for rocker install: Make sure they are 1/16" wider (outward) from the box section to account for the thickness of the rockers. Or else you'll have more cutting and grinding to do to make the quarter panels flush with the rockers. Don't ask me how I know ;-)

nuclearlemon 11-24-2008 08:20 PM

warpage? :dunno:

timmbuck2 11-24-2008 08:59 PM

wait.......Jeff doesn't know something about 40's!?!??!!!!!?!?????!?!??!?

:bolt:

Rzeppa 11-24-2008 09:18 PM

Quote:

Originally Posted by nuclearlemon (Post 90285)
warpage? :dunno:

Not likely - when you install body parts you're either welding or bolting. Any warpage is basically formed out during assembly. The seam sealer is just to fill gaps and provide some adhesion. The tricky question is why a given part might be bolted and ALSO welded to the same other body part it's being fastened to. I'm sure there's a reason, and wouldn't be surprised if it were just some logistical assembly thing at the factory rather than a well-thought-through engineering reason.

For example, the reason the frame is riveted rather than welded, is back in the day, they had not yet perfected their welding at the factory to where they trusted it as well as riveting, which was a more mature technique within their factory skill set.

Rzeppa 11-24-2008 09:24 PM

Quote:

Originally Posted by timmbuck2 (Post 90290)
wait.......Jeff doesn't know something about 40's!?!??!!!!!?!?????!?!??!?

:bolt:

Everything I've learned has either been from doing it the first time, or from others who have learned before me and generously shared their knowledge. This is my first time on this particular operation. I can see how the factory did it, but if I knew WHY they did it this way, it might give me guidance on whether to deviate a bit, maybe even improve since they built this rig 32 years ago. If there's a really good reason why they did it this way, I'll certainly stick to it.

Whether it's leading TLCA or building a 40, I want to know WHY something is done a certain way before changing the way it's done.

wesintl 11-24-2008 09:34 PM

probably depends on year too. I can tell my 64 is a little bit more crude than my 76. It was probably just what they thought was they easiest way in the factory.

Sorry no help here on why that was done.

MDH33 11-25-2008 07:54 AM

My guess would be that it had to do with the method of assembling the parts on the assembly line. Maybe some of those large parts were first bolted together, then moved to another part of the factory to be welded. Certain parts may have needed to be assembled before others, or maybe the welding took place in a totally different location, etc.

Rzeppa 11-25-2008 06:32 PM

Quote:

Originally Posted by MDH33 (Post 90309)
My guess would be that it had to do with the method of assembling the parts on the assembly line. Maybe some of those large parts were first bolted together, then moved to another part of the factory to be welded. Certain parts may have needed to be assembled before others, or maybe the welding took place in a totally different location, etc.

That's a good guess, and seems as logical as any. I posted this on the LCML and got similar responses. At this point I am inclined to put it back the way the factory did it, but am still tempted to weld the quarter panel to the box section, even though it's not welded there from the factory. Then either seam seal or body fill the gaps. This is a major rust point in the factory design and looks like it might be an improvement over factory method. Does anyone have any thoughts on why this might be a bad idea?


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