Hi,
when I bought our Priscilla, one of the exhaust manifold bolts was missing. Turned out there was a piece of about 1cm stuck deep in the cylinder head (about 1cm deep, + the depth of the manifold), with some threads left above it. So for a not-very-experienced bolt extractor like me: no chance to drill a straight hole by hand, I'd destroy the thread (or worse) 110%.
I was hesitant to repair it, and I was also hesitating to give it to a workshop (who might end up destroying stuff as well).
The solution was simple and worked more than perfectly:
get a Banjo bolt with the same thread (M10x1.5 in my case), drill through the head with a tightly fitting drill (1/8"), get a left-handed drill in the same size.
Screw the Banjo Bolt in place and use it as a guide for the lefty drill.
After 4mm drilling, use the extractor, et voila.
I was really relieved when I had this all done in 20 minutes, 2 days before leaving for Baja. Could have been wayyyyyy worse.
So if anyone can use this method - it saved me a lot of cursing! It basically should work on any bolt where you have 2-3 thread turns left (anything less than that should be easily pullable with a welded-on screw. I doubt this would have worked with a bolt so deep in the head).
Best,
Michael
when I bought our Priscilla, one of the exhaust manifold bolts was missing. Turned out there was a piece of about 1cm stuck deep in the cylinder head (about 1cm deep, + the depth of the manifold), with some threads left above it. So for a not-very-experienced bolt extractor like me: no chance to drill a straight hole by hand, I'd destroy the thread (or worse) 110%.
I was hesitant to repair it, and I was also hesitating to give it to a workshop (who might end up destroying stuff as well).
The solution was simple and worked more than perfectly:
get a Banjo bolt with the same thread (M10x1.5 in my case), drill through the head with a tightly fitting drill (1/8"), get a left-handed drill in the same size.
Screw the Banjo Bolt in place and use it as a guide for the lefty drill.
After 4mm drilling, use the extractor, et voila.
I was really relieved when I had this all done in 20 minutes, 2 days before leaving for Baja. Could have been wayyyyyy worse.
So if anyone can use this method - it saved me a lot of cursing! It basically should work on any bolt where you have 2-3 thread turns left (anything less than that should be easily pullable with a welded-on screw. I doubt this would have worked with a bolt so deep in the head).
Best,
Michael
