350C ENGINE OIL PAN DRAIN PLUG STRIPPED

[TwistedGrip]

Good afternoon everyone.
I FINALLY got the little 350C back together, filled everything with oil, started and checked for leaks (had a few), bled lines, allowed engine to get warm and went to change the engine oil and stumbled headlong into a problem. When I pulled the engine to do this repair I didn't bother to drain the oil. I've had the engine basically in my lap but never unscrewed the drain plug. Well... when I did remove the engine oil drain plug from the rear center of the oil pan most of the threads came out with the plug. It was somewhat tough to get broke loose but not abnormally. I did notice there was not a seal washer to be found but laid everything aside while the oil drained and I got everything gathered up for the reassembly. This is when I noticed the drain plug threads appeared to be stripped. I crawled back under the tractor and sure enough the internal threads are in horrible shape. Question is this... Is there a relatively easy fix for this or am I looking at pulling the oil pan on the engine as I DO NOT WANT TO DO THAT!!! I'm even pondering a rubber "swell plug" before I pull the pans. I'm all ears
Thanks in advance
Perry B

[Jim B]

You can try running a tap in it to try cleaning up the threads and put a new plug with seal washer in. JD Specs say the 350c plug is 7/8" - 20 TPI. You might try tapping it over size. Some Cummins and likely other engines, maybe some JDs, used a 1" -18 TPI plug. Lavoy may know of another good repair, send him an email. I would be leery of using a rubber swell plug, I've heard of them failing. Others will be along with ideas and may have had to make the same repair.

[Lavoy]

2 thoughts. Tap oversize for a larger plug, or bore and tap the existing plug for a smaller pipe plug, and then JB Weld the original plug in place. If all else fails, I think there is enough room to pull the pan with the engine installed.
Lavoy

[gregjo1948]

I think if the pan can be removed "easily", I would cut out the original plug hole and install a good hole from another pan. I also wouldn't use an expansion plug. Wouldn't trust it and chance ruining the engine form oil draining out.

[DrLoch]

Don't use a helicoil.... use this https://www.timesert.com/. Or, tap for oversize plug as others have suggested.