My swapmeet special aluminum oil pan (sbc 350) is leaking liberally at the drain plug, looks like it was a botched repair because of the 15mm bolt that replaces the original plug. It's obviously stripped and provides little bight before spinning loosely upon tightening. I figure I am going to have to tap up to a larger diamater bolt. It should be pretty simple, but I don't want to screw up and make the situation worse. Is ther anything I should keep in mind or is there an easier fix that I am overlooking? Thanks.
If the botched drain hole happens to be too big to use a self tapping drain plug, you might consider using a "HeliCoil" insert. VW recently used them when they went with a steel drain plug, but an aluminum oil pan. (The hard steel would gall the soft aluminum and mess up the threads after a number of oil changes). A HeliCoil insert was the official recommended repair.
YES YES Heli coil..as long as you dont tighten the plug like superman, you should be able to service the oil for a long time. Sometimes they unscrew with the drainplug, so just put in another.
Are you sure it's a 15 mm metric bolt? Because that is like 5/8 inch. A helicoil would not take up that much if you go back to a 1/2 inch bolt. For reference 1/2 inch is equal to 12.7 mm. I agree that a helicoil is the right way to fix it. Just get the right size to work with your hole in the oil pan.
There's another insert you could use called a Keen-sert which wont come out with the plug because it has four small stakes built into it that you hammer in and stake the threads so it can't come out.
Thanks for the responses. I will first try an oversized self tapper, but where can I get a helicoil or a keen-sert, NAPA have em'? Thanks again.
The DR is correct, Keen sert is the way to go. Problem is you need to buy a kit that includes a tap and instalation tool, for some this may be a little costly...........
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