Maybe this has been brought up before but how strong are these new hydroformed frames? I know they're stiffer, but are they stronger or weaker then the old design? I'm thinking weaker because of all the restrictions Dodge seems to place on them when it comes to drilling holes. Anyone know for sure?

 

I have no data but would think they would be stronger. DC or any manufacturer will put restrictions on frame welding and cutting because you know some moron will hack out 75% of it and wonder why the frame broke. : Class 7 and 8 trucks have had notices on their frames not to weld or drill unless manufacture approved for many years. I think DC is covering their butt for lawsuits. I have seen some 5th wheels installed by incompetent people who cut away a good portion of steel to get to a bolt or nut. FWIW

 

All load bearing members, frames and hitches are not to be drilled. Hydroforming has nothing to do with it. The reason is because a hole, in the wrong spot, may cause a weakness in the area. You'll also see those stickers all over big truck frames.

Odds are you could drill a hole and no problem, but there are areas wher it would be a problem, so they just say, nada on the holes.

Kinda like cell phones on airplanes. THe reason for the none use is it may interfere with navigation equip. Probably wont, but if you happen to be sitting where a particular computer or antenna coax cable runs thru, it could cause navigation errors. So they just say no cell phones.
Long winded version.

Short version, hydro forming is stronger than previous frame manufacturing process. But don't drilla hole.

 

Can anyone tell me exactly what hydroforming is? Also what about htis proces makes it stronger?

TIA

 

Wellllllllll, don't drill any holes may be a little strong statement. : In fact, you can drill holes. Just don't drill them in the top or bottom of the frame. DC approves installation of the Reese hitch setup with no hesitation as well as some others. They require holes to be drilled. In fact, you can weld on the frame if done correctly by a certified welder.

 

http://waw.wardsauto.com/ar/auto_chassis_frames_new/

 

or:

http://archive.metalformingmagazine....drof/hydro.htm

 

and:

http://www.thefabricator.com/xp/Fabr...ticle78_p1.xml

 

Any structural member, regardless of how it is made or the material it is made from, is subject to cracking or fatigue if holes (a weakening factor) are located in an area of high stress or made in such a manner that it can cause what is known as a stress raiser. It is for these reasons that Dodge probably issued TSB 13-001-03. That tells you where you can safely drill holes in the new frame.

 

Ditto Mexstan, there are DC approved drilling procedures. And, BTW most heavy I-beam style truck frames say no drilling or welding on the FLANGES, in most cases it is permited to drill or weld the WEB.

 

Many of the C channel truck frames I have worked on looked like swiss cheese they had so many holes in them (for different engine, tranny and body applications) Ford back in the 80's and 90's were the worst. We usually could find a predrilled hole to work with.

 

This hydroforming of frames scares me. It seems the benefit to the automaker is cost saves more so then anything else. I don't know if it's any stiffer after reading the 1st article. It said the old way may be stiffer. Infact there were only 2 benefits; weight (which wasn't much) and cost (Gave an example of $60/vehicle in one of the articles). BTW, I don't mind having holes in my frame because that has always benefited me in the past.

 

I know I've been wanting to install a GN hitch in my 2003 but am reluctant to do so because of the drilling involved and warranty issues....anyone have a GN hitch assembly out there that uses very little drilled holes and more existing holes?

 

My mounting brackets for the 5er hitch and GN ball plate are welded to the frame, then the rails are bolted to the brackets. There is no problem with welding the brackets to the frame, so long as the DC specs and procedures are followed.

 

My GN assembly is fabricated out of heavy plates on the top and bottom of the frame. These are bolted in place via heavy U-bolts, which wrap the frame, much like you see on springs on heavy trucks. Rated for 30,000 lbs., and voila..no drilling, cutting or welding. I like it.