HOW TO: Crossmember sectioning ...

[ChiefRocka]

As most of you know, I’ve been working on my 62 GMC Suburban.

I picked up a '78 Crossmember with PS and steering linkage off CL for cheap.

I decided for now I wanted to set up my suspension for a loooow Static drop, as I'm not concerned with Air-ride at the moment. (I'll save that for my customers )
I can’t afford one of PorterBuilts AWESOME creations, so I knew I was on my own.
To accomplish this, I knew the crossmember had to be raised. But how much ??

So, before making any cuts, I took some measurements.

I did this by first leveling the Burban to the ground, checking both the chassis and the body. Measurements could of been done with a complete vehicle, but in this case, it is on stands:
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For future reference, temporarily installed the stock front suspension, and marked the spindle location to my garage floor:
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Measurements were, First ground to crossmember, then ground to chassis:
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As you can see, the difference was 2”.

Sectioning the crossmember this amount would raise it level with the remainder of chassis.


I viewed CapKaos’ great method and decided this is the way to go.

As many of you know, I love providing pics … so more detailed pics were used here.

I could of done all this in my shop with my nice big welding tables, plasma cutter, etc.

But this was done at my home garage….basically to illustrate anyone can do it.

In fact, all cuts were made using a cheap $14 HarborFreight grinder, and lots of wheels.

NOTE: I did not like the HF cut off wheels. They vibrate a lot, and do not like a little ‘side’ load. What I mean, is I use a cutoff wheel on its side to clean surfaces, which caused it to come apart quickly and violently . The grinding wheels suck too …

Instead, I chose the DeWalt cutoffs from Lowes, as they were priced just over a dollar.

If you have access to a Plasma…BY ALL MEANS USE IT !! It will cut your time down considerably !! Regardless of what method you choose, your still going to need a welder.

Another thing I should mention….As you can see I started with a ‘loose’ crossmember. In the past I have removed them with engine in place. (By supporting engine across the inner fenders). But, unfortunately, this is not shown here. If your doing this on a running truck, SAFELY remove crossmember !!

So….here we go !

Since they were right there like two arms, I used the frame rails of the Burban as a ‘table’ , and leveled the crossmember.
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Once leveled, I scribed vertical alignment marks on the crossmember. These are used to align the upper section down to the lower once the side material is removed. All my fancy squares are outta town, so here is my creation….
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Hard to see scribe marks here…but later used a Silver Sharpie…If you look closely you can see FOUR spotwelds just above the Ubolt bolt holes …
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[ChiefRocka]

Back side as well. Scribes were made where crossmembers shape start to change anlges upwards, if you will.
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Next I made this little device to help me scribe the line. It measures ½” and 1”. I measured down from the top ½”, then connect the vertical lines….
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From the top line, I measured down the required amount…in this case 2”…
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A quick trip to Staples scored me the cool Silver Sharpies ….
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[ChiefRocka]

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Now that we are all marked up, the crossmember needs to be braced before we make major cuts. Since I need to fit a grinder, I made the top slices before adding the brace.
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Rather than weld a brace to the towers, I uses an old junkyard steering arm and some angle. Now I have another ‘tool’…. for future chops
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[ChiefRocka]

For lack of a welding table, I relocated to my red cart, which typically holds my Plasma. Leveled cart, then tacked the crossmember to cart…
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Then … carefully begin cutting. If you notice, I did not weld a brace across the top plate because I am using cutoff wheels which do not generate much heat. Otherwise I would have. However, that piece of angle was tacked to top, before welding …

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And, just like some oysters on the grill…we crack this thing open ….
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[ChiefRocka]

These tabs are part of the formed bottom plate of the crossmember. They are on all four corners, and are held in place by the four large spot welds mentioned earlier.
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Next, you remove the amount of your ‘section’ …. In my case 2”….
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After removing the two inches, the top of tab was been removed, along with the upper two spot welds. I cleaned this area, and fully welded it on both sides.
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[ChiefRocka]

Now is a good time to clean whatever grime is on the inside of the crossmember … especially the bottom …
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Here you see where I welded the tabs:
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Not needed, but what the heck:
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You can see the importance of good, square measurments:
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[ChiefRocka]

After making all my scribe marks line up, I set the level across the top half. A little grinding here and there was needed to get it perfectly level. Also, depending on how much you remove, the top and bottom portions will be a little ‘off’. This is because the crossmember tapers and gets wider at the bottom.
Shown here:
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To solve this problem, some “relief” cuts were made, and the old BFH was brought out to help out …
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[ChiefRocka]

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I even marked the location of the where I originally leveled it …
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Once you have this thing LEVEL … tack in a few places, then start your welding. I started in the front and rear middle areas …
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As needed, use your BFH and maybe a blunt punch to help you persuade the metal . I finished up all the seems, including the reliefs…
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The back side came out pretty good, so I decide to leave the welds ‘as is’ with no clean up…
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[ChiefRocka]

THIS IS WHERE ALL YOUR HARD WORK STARTS TO PAY OFF !!
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After a little grinding (ok, a lot) and some sanding … It’s starts to look like nothing ever happened…
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In certain places … You might need to go back and do some ‘fill in’ with your welder, and resand. As I will …
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But overall, it’s coming along pretty nicely …
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Again, the back side might be left as is … only attention to the nipples on the sides (they always get my attention) …
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NOTE: Another option instead of the 'relief' cut would be to cut around the "nips", then weld them back onto the top half. I chose my method because I thought it made the crossmember look a little cleaner ...
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** UPDATE **
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Before calling it good, I performed a test fit. You may find areas that need attention, either triming, and/or more welding/fill in as shown in the last two pics. Other than that, look at the clearance we gained, not mention the 2" drop off the get go without touching any other suspension component...
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You may also notice a driver side later 70's V8 motor mount. If it seems a little tall, that is because the '63 and later frames are taller. So this '62 chassis will require a little spacer. It will work out, as the spacer will be part of the upper bracing as well.

Also keep in mind this modification DOES NOT change the position of the engine.

[ChiefRocka]

To complete crossmember, side templates then plates were made and welded up:
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[ChiefRocka]

Blank for more pics .....

[ChiefRocka]

Blank for more pics.......

[ChiefRocka]

Blank for more pics....

I will be updating chassis mods for stock steering.

['65Burb]

Beautiful work. Please post your mailing address in order that I can get my cross member in the mail to you.

[tincan1966]

very well documented! Thanks for sharing!

[Pop's C-10]

nice write up

[ChiefRocka]

Originally Posted by '65Burb

Beautiful work. Please post your mailing address in order that I can get my cross member in the mail to you.

Sure, send it down !! (or up, rather )

Originally Posted by tincan1966

very well documented! Thanks for sharing!

Originally Posted by Pop's C-10

nice write up

Thanks guys.

[63sbssbbw]

Nice work Chief
T

[Andyboy]

Very helpful how-to. Nice work.

[ol_skool_chevy]

I"m keeping an eye on the post. I want to see what you do for your steering. Seem to me the crossmember is the easy part. Getting your steering geometry right in order to clear might be an issue.
Im guessing you will notch your frame or Rack ??
Very nice write up...I was lead to beleive 1 1/2" was all you could step..

[61_FL_Apache]

Very nice write up!

[RollinKaos]

Very cool , I am going to be watching this close. Since I dont have the welding skills though I might have to send mine your way too.

[CSoliz]

Hey Chief,
This thread has been needed for a long time!! Thanks!!!

[ChiefRocka]

Originally Posted by 63sbssbbw

Nice work Chief
T

Originally Posted by Andyboy

Very helpful how-to. Nice work.

Thanks, coming along ...

Originally Posted by ol_skool_chevy

I"m keeping an eye on the post. I want to see what you do for your steering. Seem to me the crossmember is the easy part. Getting your steering geometry right in order to clear might be an issue.
Im guessing you will notch your frame or Rack ??
Very nice write up...I was lead to beleive 1 1/2" was all you could step..

I will be retaing the stock steering, well the '78 steering. Yes the frame will have a custom notch to allow perfect steering geometry. (unless a rack shows up for free ... )

The crossmember was simple, but to some it might be more challenging ... thus this write up

I believe the 1 1/2" was to ease the steering issue. By notching a FULL 2", one could easily taylor by adding a 1/2" block in between frame and xmember.

Originally Posted by 61_FL_Apache

Very nice write up!

Originally Posted by RollinKaos

Very cool , I am going to be watching this close. Since I dont have the welding skills though I might have to send mine your way too.

Originally Posted by CSoliz

Hey Chief,
This thread has been needed for a long time!! Thanks!!!

Thanks....

Feel free to come by, I'll hook you up !!

[doobiebro]

Nice work Chief...how many hrs did it take you to finish that bad boy?