Frame reinforcements

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BIG_KID

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I see some trucks that have the bed touching the cab at the top and have seen some frames break in this area. Are there any reinforcement pieces to strengthen the area. Mine is fine but just concerns me. Thanks
 

df2x4

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This one here is probably my favorite. :lol:

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Brother Al

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These pics are always funny, but they only tell you what you know already... These trucks are not prone to this, so dont panic... they arent like the Toyota Tacomas, but it does happen. Usually its because they were regularly overloaded, rotted, plowed hard with, or just treated like a used *** rag in a wesson oil party of "walkers" ...

For whatever reason, GM didnt beef this area up with any boxing, gusseting, or add flare width... instead, the frame is wide under the cab, then angles upward, inward, and narrows, as it goes under the bed... Its not exactly weak, but its not exactly an inherently strong design either. GM then went and drilled a bunch of various-sized holes in this complex area to mount various parts. This problem is more common on 1500s and LD 2500 pickups because of their frame gage being thinner and I believe the HD 2500 and 1 Tons have a gusset/ in that area. Blazers/Tahoes/Suburbans dont suffer this because their body supports the frame 100x better. This problem can be made worse with aftermarket nerf bars... IE punching more holes to mount them. Some of the C/K trucks that Ive seen with cracked frames are cracked from hole to hole... the frame natually flexes and twists
...stress cracks develop over time. Its normal for just about any metal to fatigue-crack at stress points... on any pickup truck, this is the area of most weakness because the bed and body are not supporting the middle of the frame between the two body parts, which make the frame below them comparatively more rigid than that middle section. Microfractures become compounded over time, especially with abuse, and eventually join to become large cracks. This issue can be seen in cars subjected to torque-twisting. They eventually become slightly "wracked", twisted front to back with the twisting of the engine/driveshaft/axle and they have issues closing doors, driving straight, and windshields cracking. A good example of this can be seen on 3rd Gen F-Body hardtops... if you ever look at a hardtop without subframe connectors, you will notice a tiny crack on the driver's side, where the rear pillar and roof meet at the rear corner of the door glass. Its not because the car is faulty in some way, its because its the weakest area in the whole chassis... 3rd Gen Hard Tops that are drag raced hard often have big cracks on both sides. Part of this has to do with how aggressive these cars handle too. Its also why the beaten Ttop cars are rattle traps. Ive seen '94-'96 Impala SS cars with frames broken in half on the drag strip, Big Block Chevelles with frames twisted so bad they couldnt be driven. My old Chevelle broke its C-rail welds just behind the driver's door... and it only had a relatively stock 350.

FYI... Bad body bushings/rotted body mounts/broken body mount bolts usually are the cause for the body and bed to rub in that area.

Also, here is a picture of the '98 K1500, ext cab/shortbed frame I bought a few years ago. I bought it so I could build the foundation of my truck, while I drive it... Once its done, and Im ready, I will swap my Cab and Bed over.

Look at the framerails... see how the are "C" shaped if you look at them as a cross-section... they can will twist more readily than if they were a 4-sided box tube... this is why tube frames are used for performance vehicles... I am boxing the weakest areas of this frame with sections cut from other K1500 framerails and replacing some of the connecting sections with tube stock. ie, a "flat" from a passenger frame rail will be welded to the inner driver's frame rail and vise-versa...
Also, if you choose to do this, be aware that you will need to figure out your fuel and brake line routing/servicing. If its fully boxed, there is no way to access the fuel filter or any of the lines.
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Brother Al

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Thanks Guys... just doing my part to keep our gearhead hobby alive... Too many forums have gone to crap because of bad info, poor responses, and trolls.
 

GroundSpeed

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So would it make sense to box off for example 4" of the frame with like 1 foot gap? So you don't have to move the fuel and brake lines? Hopefully that makes sense
 
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