Stripped oil drain plug

I always use a torque wrench- now i’m starting to get nervous.

 

I’ve always presumed all the torque values in the FSM to be dry values, but I don’t have any evidence to back that up.

 

^It's suspicious for drain plugs, as the threads can't be dry unless you are building an engine or transmission.

Of course the dealer lube techs don't torque drain plugs, so the FSM value is never challenged through official channels.

 

My logic is based on the theory that they all must be dry values because only some fasteners/plugs would have wet values. Otherwise if they were a mixture they would be labeled as wet or dry.

 

Dunno. Whatever it is (dry vs wet) all of the Tacoma oil change videos/articles cite that number.

 

Sure, but wouldn’t it be nice to know, for all the various plugs, what the torque values are and whether they’re wet or dry, and have it from an official Toyota source so you know it’s valid data?

 

Absolutely - not arguing against that. Just saying that a lot of people take that number at face value, including me until now.

 

What does Ford, Chevy and Chrysler post fit torque values?

 

I guess the test is- are there fasteners in other applications (that would be dry) with the same thread size and pitch? How do the torque values for those compare to the oil drain plug?

 

Every time I torqued the plug to 30 pounds, I always felt it was too much. My next change will be without a torque wrench and just snug it down and look for leaks.

 

I agree. As a guy that's done most maintenance and repairs myself I've always used the snug rule. Most people with any experience know the difference between snug and crank on tightness. After a while your brain connects with the fastener size, wrench size and material you're tightening. I have 2 torque wrenches bought 20 years ago but pretty much only use the 1/2" on lug nuts. I can't remember having any sort of leak or loose fastener except 1 time. That was an oil pan plug I had 2 metal washers on by mistake (probably too many and too soon beers).

 

That are the same length and also use a gasket? Odds are almost certainly no

 

The Toyota FIPG directions say you can drive it after 30-60 minutes, but I'm letting that cure till I'm done with work tomorrow. Then I'll fill it and take it around the neighborhood and check for leaks. Not a hard job at all. 80inlbs feels like nothing, the bolts came out shockingly easy too. Guess Toyota didn't want to strip the upper assembly.

 

Was there much oil in the pan when you dropped the original pan?

When I did mine, I was surprised.

At that point I gave up doing oil changes on a hot engine. I figured what drained out of the cold engine was good enough. No burns either was a bonus as well.

 

Yeah there was a decent amount in there still, maybe half a pint. The oil pickup sits down in that little area below the plug so it makes sense, but you'd think Toyota would want all the oil to drain out.

I never change my oil hot. Did it once on my other car, never again. 0w20 is so watery that it doesn't matter anyways.

 

I didn’t think bolt torque requirements typically take into account the thread length or gasket/non-gasket, etc. just normally the material and thread size. On that note, normally in steel you want the thread engagement to be at least 1x the diameter. Not sure if we have that here, and it could be the cause of the pan stripping.

I’m a mechanical engineer, but haven’t had to specify many torque specs in my career.

 

Bolt length absolutely impacts torque value. You can read up on it in any number of physics papers, magazines or forums.

The gasket matters for a number of reasons. Impact on friction due to material, ability to compress, surface area. For example, my wife’s SUV has an o-ring between the drain plug and oil pan. Plug is about the same size and thread dimensions as my taco, likely same or similar materials involved, much different torque value.

 

If you paid attention, toyota engines went full aluminum

 

Yeah, it's aluminum. Oil pan is steel.