I have A 72 SS 402 Chevelle with A crack in the frame on the passenger side just behind the upper and lower A-arms. Is this common for Chevelles that have had high horse engines or is this only caused by A hard hit to the front?

Tommy

I'm going with the hard hit theory. I hope your frame is salvageable.

If you do a search, you will probably find it is fairly common.

yes it is common. it is not from being hit. it is fatigue. actually the frames are poorly designed. gm put tie down oval holes for hooks when straping the car to a transport trailer from the factories. unfortunatly these holes (just behingd the from control arms) were put in a very critical place. because the body adds to the regidity of the frame at the cowl or fire wall, it causes a flex point between the control arms and the fire wall. it is hard to explain but this is a bad set up. they corrected this in later years on the full size cars. caprices for example from 73 up typicaly only on wagons or police packages had cross braces that tied the frame in more of a 3 dimentional mannor. these braces went from under the oilpan frame to the corner of the frame befor it turns outward to the frame rails. then from that corner over to the frame just ahead of the crossmember in some cases. the early cars had bolt on braces the later years were welded on. i have about 4 or 5 cracked frames right now. they have never been hit and range from 454 to 6 cylinders and wagons to 2 doors. you can have this welded but there are special techniques to do it right. like drilling a small hole at the end of the crack to stop further stress, grind out the crack for good penetration, and make a good weld.

http://hometown.aol.com/smartasreality/page04.html

http://hometown.aol.com/smartasreality/images/frame05-27-02e.jpg
look to the left of this picture. in addition to the braces i amention above, i also welded triangular gussets behind the control arm mounts and welded a plug in the tie down oval as a preventative measure, since i dont plan on using those hole to strap my car to a trailer anytime soon.

Thanks very much for the reply(and the picture). I have several good welding shops in my area that can repair the crack for me once I decide what to do with the car.

Tommy

is this a hard thing to repair because my 69 fram is cracked in the same spot basically the support for the a arm is pulling off the frame i have no experience welding yet but im going to weld up some inner outter rear wheelhousings and floors/ braces first will i be experienced enought to do this with the frame and what are some things that need to be done etc.? thanks

If you're not an experienced welder capable of structurally sound welds, I wouldn't attempt this. It is not for beginners since the consequences of a bad weld are severe. Welding floor pans and wheelhouses would be a different story and a good place to learn. A bad weld here could be pretty expensive later, have a shop do it for you.

thanks a bunch i will should i have them brace both of them while there at it? and can they do it with all the body parts on etc.?