Insight Oil Pan second chance
Oil Pan second chance
Thanks to Jim Alger at Find My Insight who sent me a stripped out oil pan, I believe I have a better solution to the expensive replacement that many people have faced.
This may have actually been part of the design, as I cannot see any other reason they would have put that strange O-ring retainer in the stack of washers.
I carefully looked at the pan, and saw that there were at least 4 complete threads in the rear of the stripped out magnesium hole. I quickly realized that if the crush washer, and O-ring plate were gone, and I cleaned the remains of the old threads out of the hex bolt, that it threaded in fully, and actually came out the other side with the full 4 threads to hold on to.
I got out the trusty gasket punch set, and made a nice 1/8" thick rubberized cork washer.
I screwed the bolt back in, and found that from first resistance(initial crush), to where I felt I was going to squeeze out the cork (not likely)that I had nearly a 1/4 turn. This should seal easily between the hex plugs polished underside, and the nice flat surface of the oil pan. The only question that remained was could it work loose over repeated hot cold cycles.
I decided that since there was already a nice blind threaded hole and bolt left over from the O-Ring washer, that I may as well make a hex plug anti rotation retainer,
I dug up a thin aluminum sheetmetal plate, and drilled a hole that was just a smidge larger than the distance across the hex head flats of the hardened plug. This hex is 17MM, so as a backing cavity I used a 6 point socket, and pressed the hex head through the aluminum with my drill press. This cold forms the aluminum to make a nice snug fitting hex hole to fit the hex head of the plug. I cut out the aluminum and made a narrow tab, then carefully bent the tab to slightly less than the wide base of the hex plug and the cork washer so it would not bottom out when applied.
Finally I drilled a clearance hole in the tab for the retaining screw.
I tightened the plug with the retainer in position till the hole lined up, put in the screw, and believe that this oil pan will work as good as it did before stripping out, all without the need to do any machining or removal of the oilpan, and with only the addition of a single sealing washer.
Cork rubber is good in oil, and is rated for -40F to 180F. I just happened to have a piece, but a better washer material may be Aramid/Buna-N, which is rated for -40 to 700F
You can buy a pack of 5- 5/8" X 1" X .062 Aramid/Buna-N
washers from http://www.mcmaster.com/
Part # 93303A284 for $8.10