Today, I learned the hard way why it's bad to tighten a leaking drain bolt.

[eremoy]

I was filling my transmission earlier when I noticed I forgot to torque down the drain plug because it was covered in red fluid. I started torquing it down and right when i hit about 17ft lbs (torque spec is 21lbs on the A750E) I felt it strip out. Long story short and $75 later I have a new pan being shipped to my door

But anyways, what's the correct way to install a drain bolt? I assume the torque specs take into account oil on the threads and my problem was excessive oil on the bolt face/gasket?

 

[Morphyne]

I have had nothing but bad luck following torque specs on sensitive areas like this. So I just qualitatively tighten and go with that.

An inaccurate torque wrench can ruin your whole day.

 

[eremoy]

I have had nothing but bad luck following torque specs on sensitive areas like this. So I just qualitatively tighten and go with that.

An inaccurate torque wrench can ruin your whole day.

Yeah that's a good point. I think I'll just go by feel on the new one because I'll probably have a heart attack if I break it again lol. I'm trying to get into the habit of torquing to specs but this has me really nervous now.

 

[nevada]

I was filling my transmission earlier when I noticed I forgot to torque down the drain plug because it was covered in red fluid. I started torquing it down and right when i hit about 17ft lbs (torque spec is 21lbs on the A750E) I felt it strip out. Long story short and $75 later I have a new pan being shipped to my door

But anyways, what's the correct way to install a drain bolt? I assume the torque specs take into account oil on the threads and my problem was excessive oil on the bolt face/gasket?

what wrench are you using?
since you knew where it was when it stripped, im guessing some type of beam wrench?

 

[CXS]

When I had my Land Cruiser I adhered to "Toyota Tight" It's tight when it feels right.

 

[JEL]

Yep, stripped my stupid IS transmission drain bolt trying to adhere to the torque specs. Never had a problem on any of my Benzes, but Toyotas must use ultra-soft that's prone to stripping/snapping. I just get that sense working on my 4runner that all nuts and bolts are made of some kind of soft-ish metal, so I tread lightly.

 

[eremoy]

what wrench are you using?
since you knew where it was when it stripped, im guessing some type of beam wrench?

Yup, this one right here: http://www.amazon.com/Presa-31003-Torque-Wrench-8-Inch/dp/B00LPY2DLE. These should be reasonably accurate, right?

 

[RPS13]

Yup, this one right here: http://www.amazon.com/Presa-31003-Torque-Wrench-8-Inch/dp/B00LPY2DLE. These should be reasonably accurate, right?

Most cheap torque wrenches are accurate to +/- 4% FULL RANGE. So it's +/- 2.67 ft-lbs at any torque and within range. So instead of 17, you could have been right at 20.

That said, beam style wrenches can sometimes introduce more inaccuracies based on out of plane loading and how you look at them (way more than 4%).

 

[JB.]

On an easily accessible area like that I like to go by feel and torque to the minimum I think will seal (but I will know the published torque specs for general reference). Then I monitor.

No stripped bolts or leaks in a decade.

 

[RonJR]

The other thing about beam-style wrenches is to make sure that you pull on them in suc a way that the handle is freely pivoting on the center pin, and not at a hard stop one way or the other. Otherwise the torque reading will be off, possibly by a fair amount.

 

[pliance04]

drain plug

Oil drain plugs, trans plugs, diff, transfer case plugs are all different(duh i know) i personally don't use torque wrenches. I have over torqued plugs and cracked gaskets and such with them. I stopped using them and haven't had any issues since i stopped. And im a auto tech.

 

[Morphyne]

When I had my Land Cruiser I adhered to "Toyota Tight" It's tight when it feels right.

That's what she said.

 

[rooost]

When the spec is that low and with the accuracy or TQWrenches its a good tip to "sneak up on it" .....start a few ft or in/lbs below where you want to be, like doing a cylinder head

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yea only learned the hard way! funny things happen when you get tired !
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[gm350reratliff]

With low torque fasteners, I would suggest using a torque wrench that puts the specified torque somewhere in the middle or higher end of the torque wrench. That may mean going to an inch/pound torque wrench. Torque wrenches seem to get sloppy at the lower end. I would also use the advice that [MENTION=120157]Roost[/MENTION] said, sneak up on it. Start low and gradually increase. If you feel you have reached adequate torque before the target, stop. Just monitor for leaks.

EDIT; One more thing, when working with low torque fasteners, before going to town with the torque wrench put the square drive in a vice and get a feel for the target torque. This has saved me a few times from using a unknown faulty torque wrench that could've cost me a lot of time and money. Not only are you trying to get a feel for how little elbow grease you need, you want to make sure the torque wrench is working correctly.