Mad Dog Tannen

It has to do with how many threads are in contact, metallurgy of the fasteners/threads, what type of force is being applied Sheer/torque/?, the size and pitch of the threads, etc.

As a general rule, torque to service manual specifications. Honda engineers are smarter than you!

Also everyone in here probably has a torque wrench that is not correctly calibrated. They need to be calibrated if they are dropped (even just once) and periodically if used regularly. I also highly doubt that any of you store your torque wrenches with it set to the lowest setting like you are supposed to either.

mikey1

even more of a reason for me not to use one

Mad Dog Tannen

If you want to know one major difference between automotive mechanics and aircraft mechanics. It's the use and maintenance of torque wrenches and proper torque values.

With more exotic materials and combinations of materials, it's important to use manufacturer specs on cars too. Although I admit, I mainly do this on critical parts that bolt to the engine or soft metal and PFT less critical parts like body panels and interior parts.

ezone

Gee, when I say something like this I'm an azzhole.

EdGasket

I generally use copper washers but aneal them first with a flame and then cold water. On the Mercedes I have the drain plug torque is 18 ft-lb which is enough to part-crush the copper. The mercedes pan also has way more threads than the Honda.

Having previously stripped the threads on a 1992 Honda 1.6 sump pan which was spec'd at 35 ft-lb torque, I am now very wary of Honda pans and their recommended torque. Also wondered why it is so high compared to other brands which are generally in the mid 20s ft-lb range and whether the Honda spec.is for non-lubricated threads.

mikey1

dude, seriously, it has nothing to do with honda,

i say this with respect but,

if you can not tighten an oil drain plug properly with a wrench then you have no business performing any other major repairs on a car, you are not experienced enough to be doing so IMO,

a torque wrench should not be nessessary on an oil drain plug,

even when using a torque wrench you should be able to feel when its getting too tight and the threads are beginning to damage and you could not?

torque specs are never 100% accurate anyway, too many variables come into play, one as was previously stated, a properly calibrated torque wrench, lubrication or not, gasket type, etc etc,

even given that i would never torque any bolt to 100% of the specified value,

one of the very few bolts i DO USE a torque wrench on is the timing belt tensioner bolt, i believe it is recommended at 33 pounds?......i normally do it to 25 pounds at most,

its better to under tighten then strip the damn threads, anything past 15 to 20 pounds aint coming loose,

Mad Dog Tannen

Sometimes a torque wrench can be a very good learning tool for what certain torque feels like. Feeling if the threads are going to strip is not a good/safe/or consistent method. I say that noobs should use a torque wrench for every fastener possible. Only once the fundamentals are known should one decide to cut corners. In other words "perfect practice makes perfect".

Mad Dog Tannen

Haters gonna hate. But sometimes engineers are paying more attention to production cost and fuel economy than performance, so the rule has it's exceptions.

They can make engines that last 500k miles, but it costs a lot more to produce. People don't want to pay more, so they make engines that last 100k miles instead.

EdGasket

Ref. "if you can not tighten an oil drain plug properly with a wrench then you have no business performing any other major repairs on a car, you are not experienced enough to be doing so IMO,"

Well I have done head gaskets; numerous timing belts, couple of clutches and done up many bolts by hand. None of my work has failed. However when changing the oil, the drain plug on the Honda is round the back of the engine, there is not much ground clearance to see/feel what is going on, and the threads are obviously slippery. I prefer to use a torque wrench for drain plugs and have done all my life without any problems except on the Honda where I think the torque specifications are too high and maybe meant for dry threads; hence my question.

mikey1

raise the car up higher?

if there isnt enough clearance for you to use a wrench, how is there enough clearance to use a torque wrench?

maybe the threads on your drain plug were already damaged previously?

threads can strip over time, not just all at once, maybe your last tightening was just the final blow and would have happened regardless (torque wrench or not)

EdGasket

I just lean in from the side and push on the torque wrench until it clicks; not possible to have any 'feel' due to awkward access.