[DeTomaso] Motor Mount Bolts Sheered Off

[JDeRyke at aol.com]

This almost always happens as a result of the lower rubber discs collapsing 
from age, heat and oil spray. The rubbers deteriorate more on one side than 
the other, so it bends the upper mount bolts. Which eventually crack. 
First, order replacement rubber discs from one of the vendors! 
Second, with great difficulty you CAN probably drill out some of the 
threads remaining in the block using a hardened drill bit, even if someone 
mistakenly used gr-8 bolts (stock were gr-5 SAE; gr-8 bolts do not bend, they 
crack). But its far easier with the engine out and upside down on a bench, using 
a mill or drill press which will drill straight in. 

Its also possible to quickly blow the broken bolts out using an 
oxyacetylene cutting torch! Amazingly, bolt-pieces will come fountaining out of the 
holes in the block, leaving the original cast iron threads completely intact! 
Of course you will likely be directly below the sparkly molten steel 
fountain.... wear LOTS of protective clothing and remove any oil or grease first! 
I've done this numerous times to bolts broken off in cast iron heads or studs 
in exhaust manifolds. It always works but is dangerous (I once started a 
fire in an asphalt driveway under an engine!) and occasionally painful. On the 
drivers side, there's the gas tank, too.....After things cool, you can run a 
stock size tap into the holes to remove residual iron oxide and char (which 
seems to insulate the cast iron threads from the torch). 
Your main problem will be the two drivers side bolts due to the shifter 
shaft and other things in the way. Maybe its time for a precautionary engine 
overhaul?

If not, you can mayby drill the bolts out from under the car using a long 
aircraft drill bit or possibly a right-angle drill motor on at least one on 
the drivers side, but the results will very likely be sloppy if you're 
successful. Not to worry much- overdrilled bosses can then be retapped (again with 
an extended tap or tap-handle) for bolts one size larger. Or, as was 
suggested, use helicoils or threaded inserts. Good luck, Mike- J DeRyke