Cast iron differential bolt hole broken.
 

I posted my screw up earlier,and I'll re post the pictures if I can without my wife's help. I cracked a cast iron bolt hole while replacing the dif. cover on a 105 and have about 4 threads left. I was advised to drill it a little deeper tap it with a bottoming tap, install and build it up with JB Weld. Questions; Are there any better, or additional products than JB, and how do I drill the hole straight without using a drill press ? [IMG]dsco333[/IMG] dsco3326

Forget the JB Weld, it is a waste of time.

I am not pointing fingers, but, the cast iron broke, the JB is 10% of the strength (or less) of the CI. It will fall right off. The epoxy needs a LARGE surface area to be successful.

Nickel weld or braze is the best, some people have luck with MIG (not me).

Drill deeper, if you have material, is a good option. :bigthink:

cast iron bolt hole
 

Drill through the cast iron boss, or just deeper ? Then use stud & bearing mount ?
Thanks

We need pics to answer that, as we do not know which hole!! :bigeyes:

Here I'll help... Here's the pic from your last post.

Do you have the piece that broke off? If you do, SAVE IT. A good welder can weld it back on. Bad news is, probably have to disassemble the rear end. You have to get cast hot to weld it right, and then cool it slowly. I dunno, I agree with CAD, but with it being so high up on the trans....... Drilling the hole a little deeper and using a stud it would probably be fine.... IMO.

THANK YOU ! ------------How did you do that ?
Steve

I remembered you last post... Just went to it, copied the pic to my pc and reposted it. You're welcome!!

Multiple PIECES #%*&@#*!

:bash2: That sucks....

Another option.... Go ahead and screw a stud in as far as you can, and weld it in. It sucks when cast breaks. I know you don't like the idea of taking the rear end out and disassembling it, but i think I would for fear of the gasket at the axle getting too hot or the carrier bearing. Your choice. It could probably be done as it sits. But I really don't think it a good ideal. Besides, you have all that oil to contend with, and even with the coating in the housing, the cast will have soaked it up, which makes it VERY hard to weld. Usually, in situations like that we have to disassemble, clean, clean, clean,.... heat and cool, heat and cool to "boil" the oil out of the area and weld it... Good news is, its really good cast which means it contains a lot of iron, which will make it easier to weld. Good luck!