Frame reinforcements

That will kinda work but the weakest areas still need to be completely boxed. Ultimately, it will still want to crack from weld to weld, between those areas... The leaf spring area isnt a huge place for cracks unless there is a lot of stress put on it from say, heavy offroading or rot issues. The breaking point is the area between the rear cab mounts and the front bed mounts... that is the transistion point... its inherently weak and the focal point of chassis twisting front to rear....

Here is a picture of a '99-'07 GMT800 frame. The basis design is quite similar to our GMT400 trucks, but you can see a number of ways that GM reinforced the frame structure and near-completely boxed-in the frame transition point, as well as the front framerail section and above the middle of the spring perches. The addition of tubular steel cross-bracing also improved the overall rigidity between the two framrails... whereas our GMT400 has quite a bit of flex because of the stamped flat-stock-steel, cross-bracing.

Here is a close up of my GMT400 K1500 frame, ext cab/shortbed... its a crop of my initial frame picture. The bottom is a crop of the GMT800 ext cab/shortbed 4x4 frame. Circled in Red are the weak points in the GMT400 frame transition...

Compare the GMT400 to GMT800 in this area... noticably better reinforcement with additional gussets and cross-bracing.

My son hit the rear end (bed) of a older Dodge Dakota, when a little old lady turned in front of him, she was doing 35 or so, my son was doing 70... My 1980 Chevy 3/4 ton truck... The frame folded up like cardboard.. Insurance totaled it. If they had not, I had already planned to x-brace the frame. Put spreader bars in front and behind the x-bar... It did not do a lot of damage to the Dodge.

Chevy had some bad frame cracking, some at the steering box and other parts of the frame too.





My Chevy Luv has a better frame... It is a fully boxed frame.

Bracing will help... Just DO NOT WELD DOWN THE FRAME. Only weld at the top and bottom of the C channel on the ends of the brace.If it will make you feel better use u-channel as the brace.

When we stretched the frame on a semi-truck, we had special frame channel inserts made for the inside of the frame. Plate on the outside. AND many large bolts through all of that... we bought a horizontal drill that could be adjusted up and down that you would chain over the frame..the drill was cranked into the frame. the inside channel was stitched welded across the top and bottom to the outside lip of the frame... We used to do that with a big drill and a chain with the drill being forced into the frame by pushing the drill straight to the frame from a angle...That did not last too long on the big trucks.

I was the shop foreman where we did oilfield truck and trailer rigging.

I am overstating this point.. But it is just a FYI about what not to do, and what worked for us...
We did one ton Cab and chassis too. You can do those with out the fancy drill.

This is what I did with my frame full boxed from front to back.

DRAGGIN95 said:

This is what I did with my frame full boxed from front to back.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

Click to expand...

nice looking welding!

This is awesome information! so next question and sorry if this seems like a dumb one but I've never messed around with this type of work before and I really like my truck and want to do things properly: I live in Ontario where they use TONS of salt, so how bad of an issue is it if I were to snap or round off a bolt for the body mounts?

Hipster said:

nice looking welding!

Click to expand...

Thank you!

GroundSpeed said:

This is awesome information! so next question and sorry if this seems like a dumb one but I've never messed around with this type of work before and I really like my truck and want to do things properly: I live in Ontario where they use TONS of salt, so how bad of an issue is it if I were to snap or round off a bolt for the body mounts?

Click to expand...

Some what of a pain in the butt. Rounded of easier to deal with Good Vice Grips... Broken , well if it is flush then like most things you will have to drill it out, most likely ... Use plenty of penetrating oil first... I like PB Blaster... http://blastercorp.com/. Also use some thread anti seize when putting it back together.

No such thing as a stupid question... maybe some stupid answers. What is obvious to some people are not to others... That's why my older smarter brother lives with me. lol ... But he can always see a different way of doing things than I do...

PapaGrune said:

Some what of a pain in the butt. Rounded of easier to deal with Good Vice Grips... Broken , well if it is flush then like most things you will have to drill it out, most likely ... Use plenty of penetrating oil first... I like PB Blaster... http://blastercorp.com/. Also use some thread anti seize when putting it back together.

No such thing as a stupid question... maybe some stupid answers. What is obvious to some people are not to others... That's why my older smarter brother lives with me. lol ... But he can always see a different way of doing things than I do...

Click to expand...

VERY WELL SAID!!!

Expect to find siezed body bolts... and consider yourself lucky if that's all you have. A lot of our rust belt trucks have the issue and its not rare for the bolts to rot, get thin, and snap off after a big pothole or 3... I just lost one myself to a pothole.

Another thing to note, expect your frame's body mounts to be rust damaged, rotted badly, or totally eaten away. The Cab's body mounts can also rot away... this is actually a worse problem than having the frame rot because it means a lot more work to fix.

Rot on the frame's body mount locations is common to all full-perimeter frames in the rust belt. Water, dirt, salt, and (gasp) Calcium Chloride get trapped between the rubber bushing and frame, eating the crap out of it until there's just a passing resemblance of what's supposed to be there.. (think Titanic on the ocean floor). You can have new sections fabricated and welded-in... some folks get lucky and can weld-in giant washers in these areas. There is a company that makes them specifically for '78-'88 G-Body cars that could work, if things are not too bad. You might be able to have them made locally for a cheaper price.

I also like to use PB Blaster. I was introduced to it as a kid. Many moons ago, I made a hard panic stop in my '72 Chevelle... I heard a loud bang and felt the pedal shudder. The front pulled hard to the left and was barely drivable. (4 wheel drum brakes, ick!).
Upon autopsy, I found that the head of the brake spring retaining bolt had snapped off flush with the spindle face... tried WD40, heat, & an easy-out... nada, broke the easy-out and had to drill & retap it. Went to the local GM dealer to buy a replacement, "Discontinued"... went to a local boneyard, found a '70-'72 Skylark and went to work... Junkyard owner had become familiar with me scrounging parts for my "old jalopy" ('68-'72 Chevelles were dime a dozen then).
Spent a few days working that bolt with everything I could think of, heat, big breaker bars, WD40 (ick), die & tap oil, a breaker bar with a 6ft pipe... nothing budged that bolt. After a few wasted days, the guy pulled up in the loader and told me it was closing time... tossed me a can of PB Blaster and told me to soak it good, then hit it with heat when I came back next time. I sprayed it and he told me to keep the can. Dont remember if it was a day or three later, but I came back and hit it with heat. Popped right out like it was just put in yesterday. He didnt charge me. PB Blaster is an excellent penetrating oil.

Brother Al, you still @ the early3rdgen site?


PB Blaster FTW!!