I was just finishing up a simple do-it-yourself project (changing front differential fluid) and completing bolting cover to housing when (you guessed it) I broke one of the bolts by over tightening. Unfortunately the break is flush with the differential housing. I've tried drilling and using an 'easy out' with no success. What other options are available to me?

 

Bigger easy out & a lot of wd40. I find the bigger the hole you drill the easier they come out. Also think the 4 edged easy out works better than spiral ones. ( jmo ) Could try some heat on the housing as a last resort.

 

left hand drill bit.

 

With the head snapped off, there shouldn't be too much resistance left on the threads (as long as they were pretty clean to begin with). Left-handed drill bits help out quite a bit. Take your time and line up as close to the center of the bolt as you can, it makes a world of difference when trying to get one of those buggers out.

 

Sometimes you can slot the bolt with a friction wheel and back it out with a screwdriver

 

I always try this method first. If it doesn't work then I go to the EZ out.

MikeyB

 

Were you using a torque wrench?
If you were 20-22ft lbs is plenty.

 

Why didn't the drill/easy-out work? Did the easy-out break? Did the easy-out bottom out in the housing before grabbing the bolt? If it bottomed out, grind the easy-out a little shorter until it grabs.

Center punch the bolt before trying to drill. Cobalt drill bits are pretty tough.

You could drill it out completely and re-tap the hole a size or two bigger.

Another option would be to use some silicone gasket maker and hope that it holds.

And yet another option would be to fabricate a thick metal bracket that spans the broken bolt hole and is held down with the adjacent bolts.

 

If all else fails, go by your local weld shop and get some "stud puller" rods. Small diameter, high nickel content. Select a hex nut who's hole is just slightly smaller than the bolt. Place the nut on top of the broken bolt and VERY CAREFULLY weld the nut and bolt together through the hole in the nut. Let it cool about ten minutes and give it a twist.

 

If you end up destroying the threaded hole, go pick up a Helicoil kit. It involves drilling the hole to a certain larger size, threading the larger hole, then installing a threaded insert to bring it back to the proper threading. Not hard to do, and makes for a very professional and dependable repair.

 

The reason I wasn't successful with the easy out was that I got cold feet after hearing the horror stories about breaking the easy out and how difficult it is to remove the broken piece. I've gotten some excellent hints on getting this problem solved and will post when the mission is complete.

 

weld a nut on the broken bolt i have done it often broken exhaust manifold bolts etc. works like a charm.

 

I had this problem just last week. I drilled a hole a little smaller than a star screwdriver bit. I then put the bit in the driver and LIGHTLY tapped the star bit so that it would get a good bite. I was then able to remove the screw completly without buying a easy out or doing any welding.