Dante93GTZ

iTrader: (5)

I attempted to remove my differential cover bolts to change the fluid in my 91 Formy's 10-bolt. 2 of the bolts sheered clean off... I'm not sure I can get my drill in there to even attempt an extraction...

Obviously, the possibility for leaks will be there, but provided it seals (using gasket sealer, not the paper gasket), is there any harm in doing this? Anyone else had this happen?

BlackenedBird

iTrader: (5)

I would lower the diff enough to get my drill in there to use a drill bit & an EZ-Out.

Might hafta pull the PHB and/or shocks at the lower mounting point & jack the body up, but other than that? Nothing else should be in your way of getting to them after that.

nosajwols

iTrader: (1)

Do you have a welder (MIG)? My technique for broken bolt removal is to weld a nut to the broken bolt (through the centre). The heat from the weld frees it up, the welded nut gives me something to get my wrench on.

Dante93GTZ

iTrader: (5)

Negative; No welder at my place. I'll try the EZ out method and see if that works.

nosajwols

iTrader: (1)

Try a reverse drill bit (left had) and heat it first. Sometimes you get lucky before needing the easyout.

Dante93GTZ

iTrader: (5)

Tried every option I could - Reverse bits, EZouts - Nothing worked for either hole. I used penetrating spray on it, and even heat, and nothing - In fact, on one of the bolts, my EZout broke, and I had to put so much pressure on the other one that the handle on the extractor tool broke in 2 pieces...

I wound up using some extra gasket maker around the two holes - It appears to have worked fine, although the real test will be when it gets up to operating temp - I'm keeping my fingers crossed, although I believe I'll be revisiting this whole subject sooner rather than later....

Ugh....

BlackenedBird

iTrader: (5)

Many years ago, I had a 97 Tahoe. I pulled the composite intake off to paint it red. And 1 of the intake bolts broke.

I had the same trouble....Nothing could move it, not even the EZ Out.

I ended up drilling out the center of the broken bolt like you would for an EZ Out. Then stepped up in drill bit size, size by size. Until I got closest to the diameter of the bolt. The outside diameter of the threads. Had to be REAL careful not to get too big & hit the threads of the block, that the bolt went into.

After I got as close as I dared with the bits in size, I used a thread tap of the size of the threads. The whole time holding the shop vac hose in one hand while drilling & using the tap afterwards in the other, I managed to get the tap into the existing threads & chip away at the leftover bolt threads.

Eventually I was able to use the tap to cut away at the remaining bolt thread pieces, using the shop vac to suck away any bit that came loose.

But once I was done, I had it out 100% with zero manage to the block threads.

Yes, I was very lucky & expected to be needing to use a heli-coil afterwards, but didn't.