Broken bolt removal...again.

Hi everyone,

While removing the water pump from a Dauntless V6, two of the steel bolts broke off, leaving their stumpy remains in the aluminium timing chain cover. I'd like to keep the holes the stock size by removing these with no/minimal damage to the timing chain cover. In the past, when facing a similar broken bolt issue, I've had good luck welding a nut onto the end of the stump and using the welded nut to turn the bolt remains out. It usually works very well, as the heat really breaks up the corrosion within the threads and also allows a shot of penetrating oil to work it's way into the thread seams. My concern in doing it this way now, is that I've always done it to a steel bolt in a steel part. In this case, with the aluminium timing chain cover, I'm concerned that the heat of welding the nut to the stump may melt the aluminium threads around the stump. Have any of you tried this in the past without damaging the aluminium? It only takes a second to fill the nut hole with a weld, but there is still some significant heat developed.

Thanks,
Brad

 

What kind of welding? Acetylene, stick (AC or DC?), mig, tig?

I would stay away from flame welding it, too much heat for too long.

 

If you're mig welding you should be fine. Done it plenty of times. PeteL said, I'd stay away from flame welding. Try heating and quenching the bolts a bunch of times if you have access to a torch. During this process use paraffin wax on the hot bolt until it cools. It will smoke and probably flame a bit but this works very well when penetrating oil doesn't quite get the job done. After this then weld the nut to the bolt. I've done this tons of times on exhaust manifold bolts.

 

I did a 460 Ford water pump a few years ago, same style timing cover, same issue. The problem isn't that the threads are stuck in the block (but the probably are), it's the aluminum cover locking to the steel bolt. I ended up pulling the timing cover (chain was bad anyway) and drilling the bolts out of the block. Not a fun job. Took half an hour just to wiggle the cover off without screwing it up more than it already was... Good luck!

 

Thanks guys,

I'm using a MIG welder and the cover is already removed from the engine so I have easy access to it. I think I'm gonna give it a try. Wish me luck!!

Brad

 

Worked like a charm. The nuts were cherry red, but the aluminium stayed solid and the broken stumps grudgingly gave way. Sure beats drilling and tapping...

Brad

 

yeaaa!