Torque on drain bolts

["Tom Brown" <tbrown@xxxxxxxxxxx>]

Thanks, Robert.  At least someone agrees with me.   I've always tighted
drain plugs on my BMW cars and bikes to a reasonable torque, enough to
squash the washer a little.  You can feel it when it starts to deform.  I
give it a good deformation and leave it.  I've been running cars all weekend
at track events for years and running bikes cross country and on tracks.
They never come out or get loose.   I tried doing the factory torque
recently and was amazed at how much unnecessary deflection it puts on the
washer.

The lower torque is not to save money.  I usually buy crush washers in every
size a dozen at a time and put them in my tool box.   It's simply that, if
I'm ever on the road and need a change and don't have a washer, I can reuse
the old one if it's not destroyed with the stock torque.

The stripped threads thing is usually not a problem with BMWs if you use the
stock torque, but it is an aluminum thread and can be stripped.  Make sure
everything is clean.

Anyway, to each his own, I guess.  Just letting people know that the BMW
threads are very fine and put a lot of leverage on the bolt with not much
force on the wrench and the aluminum crush washer serves as a lock washer
too.  It keeps the bolt on if it's deformed and you don't back it off.

If you always calibrate your $700 torque wrench and always torque to spec.,
you certainly won't hurt anything except the crush washer and your knuckles
when you try to remove the drain plug.

I certainly understand that a lost drain plug is a serious thing and I
wouldn't write this if I didn't have a lot of confidence in what I'm saying.
I also agree with Robert that things like front wheels and brakes and covers
and things require accurate, well, at least even, torque.  Engine components
require accurate torque as well as consistent torque.

OK, end of thread?  Naaaaaa......

- -TB

>I do not torque to their specs because I do not want to strip any
threads. A lot of the values they use for bolts and drain plugs are too
tight and I am the one who will have to pay to have stripped threads
repaired, not some over-zealous engineer with a lawyer looking over his
shoulder. Now for bolts that secure the front or rear tire, I follow
the manual.

Robert

04 Yamaha FZ6

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End of oilheads-digest V1 #152
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