Quick PSA about torque specs:
Torque specs are usually provided for lubricated and un-lubricated conditions. Lubricated threads typically have a spec about 30% lower than dry threads. [BTW: In the case of hardened materials and/or type of oil used, lubed specs can be as much as 50% less than dry specs]. The convention in mechanical engineering publications is that an unspecified torque spec is assumed to be a dry specification. When a range is specified, the low number is for lubricated conditions.
If you look at the drain plug torque specs here, some specify a range and some do not. Where ranges are specified, you'll notice (almost without exception) the low number is 30% lower than the high number.
http://www.hollonoil.com/OCH/Engine Drain Plug Torque Chart.pdf
When you tighten lubricated threads to dry specifications, you're over-tightening by at least 30%. Some food for thought: https://www.engineeringtoolbox.com/torque-lubrication-effects-d_1693.html
Finally...
In my younger years as a mechanic, I did hundreds of oil changes and never used a torque wrench. After servicing the same cars a couple times per year over a period of many years (not to mention 4 decades of doing my own oil changes), I never had a problem with a drain plug (or oil filter) that I tightened being too tight or loose. How in the world anybody who works in a garage shop, can over-tighten a plug that way, is totally beyond me.
It seems these days, a torque spec and torque wrench for drain plugs is necessary. -Sad... At 60 y/o, I've done a lifetime of oil changes and am grateful it looks like I'll be doing lots more. Not looking forward to the day when someone else has to do it for me.
Ray
Torque specs are usually provided for lubricated and un-lubricated conditions. Lubricated threads typically have a spec about 30% lower than dry threads. [BTW: In the case of hardened materials and/or type of oil used, lubed specs can be as much as 50% less than dry specs]. The convention in mechanical engineering publications is that an unspecified torque spec is assumed to be a dry specification. When a range is specified, the low number is for lubricated conditions.
If you look at the drain plug torque specs here, some specify a range and some do not. Where ranges are specified, you'll notice (almost without exception) the low number is 30% lower than the high number.
http://www.hollonoil.com/OCH/Engine Drain Plug Torque Chart.pdf
When you tighten lubricated threads to dry specifications, you're over-tightening by at least 30%. Some food for thought: https://www.engineeringtoolbox.com/torque-lubrication-effects-d_1693.html
Finally...
In my younger years as a mechanic, I did hundreds of oil changes and never used a torque wrench. After servicing the same cars a couple times per year over a period of many years (not to mention 4 decades of doing my own oil changes), I never had a problem with a drain plug (or oil filter) that I tightened being too tight or loose. How in the world anybody who works in a garage shop, can over-tighten a plug that way, is totally beyond me.
It seems these days, a torque spec and torque wrench for drain plugs is necessary. -Sad... At 60 y/o, I've done a lifetime of oil changes and am grateful it looks like I'll be doing lots more. Not looking forward to the day when someone else has to do it for me.
Ray
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