Stripped the oil pan on 2010, labor hours

Yeah, we call that stripping the threads.

 

Bazinga!!!!

SCH-I535

 

I my previous employment on investigating failure of materials, I call it like a "game of picking cards from a deck."

Evidently, the OP drew the wrong card.

The foundry that smelts steel alloys makes preforms the operation like it's baking a cake.

As the components in the steel cools, the elements, iron being the most plentiful, crystallizes in a solution of molten fluid. The crystals grow into each other and forms interlocking bonds. It is the "luck of the draw" as to how strong these bonds are.

All threads are cut with taps. Hopefully, the alloy is malleable rather than frangible. Tapping strains the metal. Frangible materials like ceramics develop "cracks" on the molecular level. Malleable alloys are "ductile" or deform when cut or strained. As a machinist, I can "feel" how metal shears differently from one area to another in the same piece. CNC machines and robots have no clue.

A classic study would be the most famous example of "brittle fracture" of all in the steel of the SS Titanic. In the frigid waters of the North Atlantic, the ship's steel failed on account of "brittle fracture" rather than being "bent."

Bolts have been screwed into nuts, tensioned or torqued for hundreds of times without failing. The wrong set of circumstances would cause the threads to fail, even if the drain plug was NOT torque to the designed tension.

 

Yeah, we call that luck. Sometimes you have it, sometimes you don't.

 

If I was the mechanic "rethreading" the drain hole, I would and can actually feel how good and strong the resulting threads might be.

A CNC machine cannot do that. While CNC machines have replaced the "hands on" machinist, a young man apprenticed to an experienced "hands on" machinist will eventually be a very rare and sought after person.

It's like experienced mechanical watchmakers. They are a dying breed. They're skills will eventually be in great demand in a niche market.

 

Its a good idea after about 5 oil changes to buy a new pan bolt. The bolt is somewhat softer than the pan itself.
The Gen 2 for instance was $9. Take a good look at it after about 5 changes and you'll see the threads are starting to get wider.

I use Jiffy Lube once in a while and always mention it to the guy not to mongo the pan bolt on. The dealer is bad about that too but you can't ever talk to the dude who's touching your car. I'm certain anything you say to the service writer never makes it back there. There all so afraid the bolt may come out and blow the motor up.

Btw, take some pictures of the motor's internal bottom end with the pan off. Let us know what kind off motor oil you run and at what OCI we want to see how it looks.

 

I like that idea, just a $7 gasket, we could start a thread showing off our innards.

 

Actually, the welded on NUT on the pan is annealed in the welding on process, which makes it softer, not harder than the bolt or plug.

The NUT is threaded with a high speed spiral tap in the manufacturing process. The bolt or pug's threads are "rolled" on threading dies. This work hardens the threads on the plug.

Torqueing the plug to a lower value adequately retains the plug and applies less stress and strain to the assembly, resulting in a lower failure rate.

Unlike parts under stress and strain with parts fastened together with bolts, there is nothing for the oil plug to do but to stay there by itself.


28 ft. lbs.. is NOT necessary. 15-20 is all that's needed.

 

I agree with Rude person's. I stopped using a torque wrench on the drain plug because at the specified 27 ft/lb it felt like I was over-tightening it. I went back to wrench tightening it by feel. I have never worn out a drain plug, oil pan threads or had a drain plug come loose on a Toyota, even on the 1990 Camry that I changed the oil every 3 months/ 3,000 miles for 16 years.

 

My brother came in one day had his trailer with some shelving and a 15 gal. oil drum. When he unloaded, he had to get the tractor to lift the drum off the trailer, it was 2/3 full of oil pan drain plugs from the Quick change oil station. That's a lot of gorilla goof ups and the exact reason I change my own.

 

Please see the bottom under tips where it says the bolt is softer than the pan:

How to Fix an Oil Pan Drain Plug | eHow

 

They are WRONG. They don't understand how these parts are manufactured.

 

Ok but please see Milman's post about blown out plugs. Not so much goof ups but worn out plugs. Easy to see. They strip rather easy after a while.

 

It is well known for hundreds of years that bolts fail before the tap threaded holes and nuts. They will snap first. This has to do with tensile strength and nothing to do with "hardness."

Thread galling has to do with friction due to miss match or from cross threading.

 

There are plugs in the barrel that have nothing wrong with the threads, I think these had pulled the threads out of the pan and they just screw in an oversize plug that is self tapping and send the customer on his way.

 

Or the "technician" accidentally drops the drain plug when removing it and it falls into the barrel through the large funnel they use to catch the draining oil.

SCH-I535

 

An "oversized" self tapping plug with an industry standard called a "type F" thread might be OK for the occasional user, but will not last under repeated installation and removal for changing oil.

drilling out the hole and re-tapping it with a precision tap is the only viable long term solution. If done right, it is BETTER than the factory original.

 

But it gets the unknowing customer out the door, less his bill for a cheap oil change and the next cheap oil change place can tell him how his oil pan is messed up and he needs a new one.

 

This is NOT how I do business.

The tap and 1/2 inch drill bit does not cost that much. M14x1.5 oil drain plugs cost less than the self tapping type.

Drilling out the old thread and tapping it out to M14x1.5 takes less than 5 minutes.


Maybe I'm OLD SCHOOL, but I believe in taking care of the customer as if I am on the other side.

 

A caveat is that the tapped hole has to be rather square to the seating face. If not the pressure on the washer will be uneven and the plug can leak.