Not happened to me. Before I would think about tapping, I would pull plug and head to a good auto parts store or two and see what they have on an oversize rethreader. Or try a crushing type washers if available with a little non-hardening sealer on threads.
Edit: there are several oversized drain plugs on Amazon for $6 or so. depending on thread size, some with rubber gaskets so it does not take as much torque. I would be a little skittish about not wanting it to vibrate out but the fill hole does not get as much anxiety as the drain plug.

 

I think someone on here just had the same issue. May want to dig around for that thread.

 

Thanks bud, pain in the butt for sure. On the up side I found it before burying it in a water hole, and the gear oil was clean as could be coming out.

 

I wonder how they come up with the rating. Ft/Lbs to tighten to. Torque until they get it to strip, then subtract a few ft/lbs off the strip point for tightening.

 

I’m a hammer, duct tape and glue kind of guy. I would put some black or grey rtv on the threads and tighten it as best I could. It’s really just a plug and not under a lot of pressure or stress.

 

I periodically watch a mechanic on Youtube , South Main Auto, and he redid a stripped plug on a Hyundai with a heli-coil type kit that he says is premo. And pricey. But no drilling with a drill. It is all by ratchet so if something like that is of interest you could check that out.

 

I would try a lock tight, I think blue if that is the mildest one and a thin rubber washer. Check the threads on both the plug and the hole. You may of gotten lucky and pulled a plastic thread not aluminum .

 

Just a follow up folks in case someone runs into the same scenario. I read a few posts on the drain bolt having unused threads further in which saved a few guys so figure it was worth a try on the fill.

I tried to spin in a slightly longer m10x1.5 but felt like it was bottoming out. On examination with a flashlight you could definitely see the fill hole had threads further back in but looked like when the forward threads pulled out they damaged the beginning of what was left. I carefully spun in an m10 tap and you could feel it cut through the damaged section then smooth out on the remaining threads. After, my longer bolt went in like butter.

Crisis averted and mental note to keep my gorilla paws off the ratchet and on a torque wrench in those aluminum mounting areas

Frisky

 

Maybe we should just swap the fill plug with a longer one so as all the threads are in use. How deep was it you used. The notes M10 x 1.5 is only the thread cut if I am reading it right.

 

I have misread torque specs as lb/ft when what it stated was in/ft. Big difference!

 

Fill plug, drain plug, don't need a lot of torque. But the fill plug on my rear diff takes a 21mm wrench. Hmmmmm. I know they did that so the hole is large. But with some care they could design a plug for that large of a hole with a 10mm head on it.

Anyway, I did front and rear on Friday and wow, I sure did remember this thread!

 

Maybe I shouldn't try and out do that implementation as long as its fine. I just tighten by hand myself. I don't have confidence at low ft/lbs in the wrench as it also way too easy to over do it with a ratchet at least twice as long as the non torque one.

Thx