Welding On Bus Frame...OK or Verboten?

[CaseyBrown]

I plan on installing outriggers for levelers. I have heard that welding is a no-no on truck frames because it will ruin the temper. On the the other hand I have seen welding done.

So, whats the scoop, can I weld to the frame, or do I have to bolt things on ?

 

[jake_blue-SKO]

Are you worried about voiding the warranty? Lol

Idk but even my 80k # rated tractor trailer has everything bolted up to the frame so there must be something to it.

 

[EastCoastCB]

I plan on installing outriggers for levelers. I have heard that welding is a no-no on truck frames because it will ruin the temper. On the the other hand I have seen welding done.

So, whats the scoop, can I weld to the frame, or do I have to bolt things on ?

I wouldn't weld to the frame.
But I'm not surprised folks do.

 

[Tango-SKO]

Best bet is to check with the manufacturer. It all comes down to the steel. I have always been told by old school builders that the pre-war frames are particularly sensitive to reheating and welding should be avoided or very carefully controlled. They were designed to flex a lot. Post war frames use different metallurgy for a more rigid engineering approach but you still need to know what you have and what will affect it.

Likewise...drilling for bolts is supposed to only be done on the upper and lower sections and never on the vertical portion of the rail. GM has sent warning notices out on this but lots of people do it anyway.

Lots of stories out there. Like I said...best bet is to check with the chassis builder.

 

[CaseyBrown]

Yep, It's a warranty concern

I noticed that EVERYTHING attached to the frame is bolted on this bus. It could be that it's way easier to assemble consistently in the line (no welds to inspect). I would much rather arc some beams to the frame than trying to line up holes (not to mention drilling said holes) while laying under 100LB plus chunk of steel. But, I don't want to warp, or weaken, the frame either.

Unless someone can point out "why not to weld", I'm leaning (hard) to welding.

 

[TheRainbowBoxer]

We are attaching to the frame using welding. I don't anticipate any issues, but I have found out the hard way a couple times that doing things out of the norm sometimes causes headaches.

 

[CaseyBrown]

"Likewise...drilling for bolts is supposed to only be done on the upper and lower sections and never on the vertical portion of the rail. GM has sent warning notices out on this but lots of people do it anyway."

Interesting. There are a bazillion bolts on the vertical...practically all of them.

Any idea who made the frame on a '96 TC2000RE?

 

[Tango-SKO]

GM was only concerned with any additional holes. Their engineers had worked out how many and where to avoid weakening.

 

[ol trunt]

To pick up where Tango left off, when I was building my bus I added outriggers to support the bus body on the Chevy W3500 chassis I used. In my case, the chassis is mild steel so it is pretty forgiving. I should point out that the top and bottom portions of a channel frame are called flanges while the vertical "side" is called the web.

I went to the following website for specific info on frame modifications for my particular vehicle, but I think the info presented there would be a good starting point for anyone contemplating frame modifications. In particular, pages 15-17 should be of interest.

https://www.gmupfitter.com/files/media/photo/202/2007_MD_LowCabForwardW.pdf.

Hope this helps. Jack

 

[Brad_SwiftFur]

I would highly suggest bolting things on, unless you are a certified welder and know metallurgy and you really know exactly what you are doing. Consider this - the landing gear for most heavy road trailers is usually bolted on and for good reason. These systems can support many thousands of pounds and even the impact of a heavily loaded trailer being dropped on them. They are typically bolted on with 8 or 10 bolts per leg. Welding will alter the temper of the steel; drilling holes less so. The frame's main strength is in the flanges, a few carefully placed holes in the web shouldn't cause an issue. Consider that the factory put plenty of them there for attaching things. Also, welding them on will make future replacement that much more difficult. Suppose you bend one? Cut/grind/weld (and further alter the temper)? Or, undo a few bolts, bolt on the new, and go about your way?

 

[CaseyBrown]

Thanx for the pdf link ol trunt..it was interesting .

Basically I'm looking at welding a piece of 4 or 5 inch box beam just in front of the rear wheel wells, and just behind the front ones, under the frame. I'm not looking for the strength to lift the bus with jacks, just enough to unload the springs so it feels solid walking around and minor leveling. If its very uneven I would drive onto blocks first. To that end I see myself "stitch"welding with beads no longer than 3/4" along the bend where web turns to flange.

 

[CaseyBrown]

Well dang..looks like the weld/not weld is heavily leaning "not weld".

Guess I'll think some more on this.

 

[jake_blue-SKO]

Just a thought... What about a small box beam spanning beneath both sides of the frame and then bolted up with U-bolts? No drilling or welding on the frame at all.

http://www.pplmotorhomes.com/parts/rv-jacks/rv-electric-stabilizer-jack.htm

 

[Lbickham]

I have worked on semis and trailers and we never welded to frames. A previous poster was right, it messes with the temper. If you look at new semis and trailers, everything is bolted on.

 

[Crazy]

Next time you pull up next to am Isuzu box truck, look at the frame. There are hundreds of holes in the frame from the factory. They are the only truck that I have seen like that.

 

[Hank's P-O-S]

I know some people don't like Nat, but up to this point he has presented the argument in the simplistic terms.
This is a quote from my trailer hitch thread that wound up in a mess.

"
What this should have said was
"Don't drill holes within 3/4 inch of the shoulder of the frame."

If the holes are no bigger than 3/4 inch, and centered in the flange,
your fine.


Welding to the frame is a no no. It will cause the hardened steel to crack.

Nat
"

I would like to add, That the centered part does not apply to the web of a frame. but the 3/4 inch from the shoulder does.

 

[CaseyBrown]

"Welding to the frame is a no no. It will cause the hardened steel to crack. "

That settles it. You had me at "crack". Got my attention a little better than "temper", or "strength".:biggrin:

" What about a small box beam spanning beneath both sides of the frame and then bolted up with U-bolts? No drilling or welding on the frame at all."

This is the direction it looks like I will go.

Thank you everybody for all the excellent info :Thanx:

 

[dgorila1-SKO]

To pick up where Tango left off, when I was building my bus I added outriggers to support the bus body on the Chevy W3500 chassis I used. In my case, the chassis is mild steel so it is pretty forgiving. I should point out that the top and bottom portions of a channel frame are called flanges while the vertical "side" is called the web.

I went to the following website for specific info on frame modifications for my particular vehicle, but I think the info presented there would be a good starting point for anyone contemplating frame modifications. In particular, pages 15-17 should be of interest.

https://www.gmupfitter.com/files/media/photo/202/2007_MD_LowCabForwardW.pdf.

Hope this helps. Jack

That was interesting and informative. I like the drawing showing how to properly attach bracing to the frame channel. The ends must be cut at 45 degrees and plug welds or cold rivets used. No stitch welding or perimeter welding of the brace is allowed for proper strength. Great info Jack!

 

[Stu & Filo. T]

"I would like to add, That the centered part does not apply to the web of a frame. but the 3/4 inch from the shoulder does."

For clarification, Is Nat saying it's ok to drill in the web as long as your more than 3/4in away from the shoulder??

 

[cadillackid]

ive always bolted to the frames... if I needed something where there wasnt a hole or a boss I sometimes created my own brackets that would hang over the top of the frame, or fabricated brackets.. I was told that drilling in the frame was Ok for horizontal surfaces as long as I never exceeded 40% perforation in any 6 square inch section of the same frame surface.... that came from an old GM guy and it pertained to body on frame RWD cars and light trucks..

-Christopher