Subframe Crack - 79 TA
 

Looking for some guidance here. I was doing some cleaning and prepping of my engine bay with the engine out and noticed this crack in my subframe. This is on the crossmember portion under the engine. Does anyone think this is repairable via welding or do I need to bite the bullet and get an entirely different subframe?

Also, does anyone have all of the measurements handy for checking a subframe for squareness?

Any help/guidance is greatly appreciated.

Wow, I saw the first two pics and thought about "Ving" it out and running a bead in there. Then I saw the third picture. Sorry I do not have measurements.

The frame people at Snap-On/Blackhawk will have measurements.
Great catch, it looks like the metal was a little too brittle.
Should be fixable.

Meausurements are in the fisher body manual. I dont have anything on the computer to scan, would have to dig the book out of the shop.

You have a tough decision to make.

I would want to know why it cracked before making a decision to repair or replace, but that's just me.

You seem to be questioning whether the part could have been bad and therefore, not worth repairing, correct? Like 694.1 speculates about the material being brittle...

The jagged, random path of the crack suggests to me it developed slowly over time...probably fatigue and could have been helped by corrosion. Brittle cracks tend to propagate fast and in a straight line like the pink:

http://forums.maxperformanceinc.com/...1&d=1700237922

But the crack wouldn't be there without this being a high-stress location for the part.

The part is probably stamped from relatively strong cold-rolled steel so welding should be able to repair it. How long it lasts after comes back to understanding why it cracked but, IMO, the crack by itself doesn't say the part was bad to begin with.

You also know replacing the part removes a lot of uncertainty. If you weld it, will you trust it or worry about it?

Good luck.

Mike

It appears you have the original bridge jump Bandit.

I'd replace if it were mine. Can be fixed as is but I'd want mine ground back flush and unseen and paint touched up, easier done when not attached. Perfect time for a nice powdercoated finish to protect before slipping back under.

Thank you all for confirming what I already suspected. I believe I have already sourced a local replacement from a 78…now the fun begins.

I was gonna say I have one but not very close.
May be a blessing in disguise. This way you can strip everything down and start new!

I'll definitely be able to do an even more thorough cleaning/painting than I ever anticipated on the bright side haha.