Crack behind weld.

Wingman357

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I have a situation involving a stress crack on a 1600 car. See first photo.

The tube below it has been sleeved\rossete welded and I was wondering if I should do the same thing here (see 2nd photo ) or if I should just gusset it ( see 3rd photo )and weld up the crack.

Or maybe cut out the tube, replace it and sleeve it externally like my front end (see last photo )


???????????:confused:
 

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matt_helton

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id cut that whole tube out and replace it. and when you re-make your upper trans mount tube, make that tube overlap the bottom of the joint where that crossmember tube hits the midrail.
 

Wingman357

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"make that tube overlap the bottom of the joint where that crossmember tube hits the midrail. "




Kind of confused about what you mean, so here are a few more angles. Its has the same crack on the opposite side of the tube behind the oil filter. As you can see the tube is braced in about four spots and replacing it looks like a lot of work......I'm not scared, just sayin. Where should I start???
 

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stealthcammo1

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cromoly? my neighbors class 9 did the same. i drilled out the ends of the cracks with a 1/4 inch bit and then weld up the crack. also adding that brace afterwards would be a good idea.
 

empire_637

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I would do what matt's saying cut the old tube off and replace it with a new one.
 

DBMETALWORX

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I would cut it out and replace it.. It obviously takes a beating, so you may want to step up the thickness as well..
 

Wingman357

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So basically cut it out like this??????.......See photo

What would be the best way to cut it out (tool wise)?? I know I can hack it off with anything, but Im talking about cutting it clean, so that the new piece fits nicely ( plasma\flap wheel, cutoff wheel\flap wheel, etc.)????????


I have never replaced a tube that has been fishmouthed into at multiple spots along the tube. What are the do's and don'ts????
 

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Brian Mapes

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The best fix for that would be to completely remove the old tube that is cracked. Then grind away the old welds as well. Make your new tube and put it in. Weld it all up then add the gusset like you pictured in the beginning. Use whatever tool will fit in the area. Plasma or sawzall would be my choice, then use some type of grinder to finish the job clean.
 

Wingman357

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when you re-make your upper trans mount tube, make that tube overlap the bottom of the joint where that crossmember tube hits the midrail.
[ame="http://www.youtube.com/watch?v=Qw9oX-kZ_9k&feature=related"]YouTube - Whatcha talkin bout Willis[/ame]
 

Tipracer

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I think that there is more going on with your frame than what you see there....that crack was cause by the frame twisting more than it shoud(especially in that location), imo you should look really close at the frame , I would not be suprised to find that you have another crack elsewhere. repairing that crack will fix the problem for a short time but i bet you will find that it reapears again, This is not the first time that I have seen a crack in that area, when we finally found the problem on my buddys 16 we had repaired it twice, btw look around the torsion housing. With the forces the motor and suspension put on that area one crack allows the whole back half to start flexing, causing what you have there.
 

westhoffmotorsports

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I had the great opportunity to build my own 2-1600 car which was an awesome experience. Here are some pics of the way I mounted my transmission and ran tubes all the way from that same joint to bottom tube. It works great and havent had one issue yet. My suggestion is to cut all the tubes out from the mid rail to to bottom tube and run them down like I did on my car. When you look at your pics there isnt really and triangulation in that section of the tubes. Triangulation and tube placement helps with cracks. I have a whole bunch of pics on my website of the build. www.westhoffmotorsports.com

Let me know if that helps and good luck!
 

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Wingman357

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I think that there is more going on with your frame than what you see there....that crack was cause by the frame twisting more than it shoud(especially in that location), imo you should look really close at the frame , I would not be suprised to find that you have another crack elsewhere. repairing that crack will fix the problem for a short time but i bet you will find that it reapears again, This is not the first time that I have seen a crack in that area, when we finally found the problem on my buddys 16 we had repaired it twice, btw look around the torsion housing. With the forces the motor and suspension put on that area one crack allows the whole back half to start flexing, causing what you have there.
I forgot to mention the part about getting clobbered from behind by a 10 car. I'm sure that had something to do with it also.....lol.
 

partybarge_pilot

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The whole reason that tube is cracking is the small cross section. If you just grind out the crack and weld it up, add the gusset you had pictured above (which should have been there from the beginning) you will be fine for years to come. Cutting out the tube is a lot of work for very little gain in this case, it's not the tube it's the design.
 

partybarge_pilot

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I think that there is more going on with your frame than what you see there....that crack was cause by the frame twisting more than it shoud(especially in that location),
It could use an X brace in the rear also to keep it from twisting side to side.
 
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