'72 stripped drain plug threads in oil pan

[Billy Olson]

The threads in my oil pan are stripped. I had used one of those universal repair plugs with the toggle bolt and rubber sealing surface but now want a permanent fix. I see there are oversize/self tapping plugs but they look too large. Is there a special oversize plug made specifically for small block Chevys? Any solution ideas are appreciated. Thanks.

Billy

[Tracy C.]

Re: '72 stripped drain plug threads in oil pan

I'd remove the pan, grind off the internal thread flange and braze a thin correctly sized nut over the drain hole.

Your pan gaskets are probably leaking and due for a change anyway..

tc

[Don Y.]

Re: '72 stripped drain plug threads in oil pan

Billy,
I recently repaired my oil pan with a helicoil. I drilled and tapped per usual instructions and then wound the helicoil into the drain plug boss. I marked the insert where it hung out of the bottom of the pan and then wound it the whole way through the drain plug boss. I snipped the insert off and trial fitted it until I had about 1/2 thread clearance in the top and bottom of the pan. The plug snugs up perfect and there is no interference with the plug or gasket. There are nearly as many full threads as the original pan boss. The oil pan was off so chips and debris were not an issue. It just took some fitting to get it the way I felt it would work well.
Don Yesacavage

[Clem Z.]

Re: '72 stripped drain plug threads in oil pan

if you are not worried about NCRS correct the auto parts sell self threading oversized plugs for all cars

[Rob A.]

Re: '72 stripped drain plug threads in oil pan

Billy,

If you decide to remove the oil pan, after properly cleaning the area, you can weld over the existing stripped threads, filling them in. Then re-drill and tap new threads in. It's not as much work as it sounds. A really good welder can apply just enough weld into the damaged threads so all you have to do is re-tap the threads and you'll be able to use the original drain plug, if that's important to you.

[Billy Olson]

Re: '72 stripped drain plug threads in oil pan

Thanks for all the ideas. I'll pull the pan and I think try the welding of the threads first.

Billy