Welding Brackets to 12 bolt Housing

[AButler]

Im looking to weld some brackets onto the center section area of a 12 bolt. But it is nodular iron. So can i just weld it on or what steps do i have to take. Is it structally ok to do?

[MrQuick]

you making a 3 link?

[JMarsa]

You need to look into welding cast iron. It's not like welding a mount on a 9".

--JMarsa

[AButler]

....

[AButler]

yes i was thinking about it but not sure if i can use a 12 bolt housing or not. I would prefer to but there is other options

[AButler]

This is an axle truss for a 4x4 set up but i figure i could lower down to right on top of the housing and use the front of the bolt flange for some added support.
http://www.ruffstuffspecialties.com/catalog/medium-weight-p-117.html
https://static1.pt-content.com/images/noimg.gif

[JMarsa]

Mock something up with cardboard to make sure you have the space first.

--JMarsa

[wendell]

I built a top link mount for a 12bolt and it was a pain in the ass. If you're planing on sticky tires I wouldn't try to weld on the cast pumpkin. Even if you do everything perfect (pre/post heat) I'd still expect it to crack.

If I did it again, this is what I'd do...
Cut a piece of 3/16" plate to match your cover gasket and extend above the diff to the height you need for your top link. Sandwich it between the diff and the cover. Cut 3/16" side plates to run from the back piece to the webbing at the fron of the diff. Weld flanges on at the front that will bolt to the webbing.

Don't know if that makes sense but its how I'll do it next time. My original design took three interations before it would hook 600hp w/ a 9.5" slick. I'm confident this idea would do the same with less weight.

[JMarsa]

Here's an idea I think is better than the truss above:

https://static1.pt-content.com/images/pt/2007/10/mainphpg2_viewcoreDownloadItemg2_itemId1-1.jpg

From this thread: https://www.pro-touring.com/forum/showthread.php?t=34498

--JMarsa

[AButler]

Thats more on the path that i wanted to go with but i searched and searched and counldn't find anything close so i figured it would just fail or twist. I see how it reinforced it with the other tube. Do you know what size tube that is????? 1.5" DOM but what wall thickness? the thickest i can get????. Also i notice that alot of people use rod ends on their 3 links why? Another question all the links i see seem to have the threaded Bungs welding in. Can't i just thread the tube and go that way?

Aaron

[wendell]

You absolutely can thread the rod and scip the welded bung. The pic above looks pretty good. The only thing I see is that the horizontal hoop towards the front isn't doing anything is it's not tied into the diff near the pinion. If it's tied to the pinion then you're in the same ball park as what I was suggesting. Nicely executed regardless.

[JMarsa]

The forward loop looks to be supporting the bracket tab.

https://static1.pt-content.com/images/pt/2007/10/mainphpg2_viewcoreDownloadItemg2_itemId1-2.jpg

No idea what spec on the tubing is. I think bungs are used because they are more expensive :)

--JMarsa

[wendell]

While it's supporting the bracket tab, all the load is still placed on the two axel tubes. If it were tied (bolted) to the web of the diff, you'd have a much more robust assembly.

I agree about the bungs but in a an aplication like this (where the vast majority of the force is in tension) bungs will let you use a very thin walled (light weight) top link. Only relavent when every pound counts.

[AButler]

where would i bolt it. Would i need to seal the bolt somehow to prevent leaks? Or do you mean the cast ribs that are like fins. Would that cause any stress and just break off anyway. The only forces that that tab sees is forward and back no side to side correct?

Aaron