Also, about using torque wrench, I know everyone suggest to use it as newbie sometimes just don't know what they are dealing with.

My last night experience was totally opposite.

I changed real diff first. After all old oil drained out, I put the plug back, set my be loved torque wrench to 36 which some one mentioned here. I turned and turned and waiting for the 'click' sound. The 'click' music didn't come out of it before I actually crashed "too much" the crash washer. I then realized I might tight it way too much. I headlight it and look at it, I saw crash washer was squeezed too much and one side had already extended to broken. It is not leaking yet. But I am worried.

So, last night, for all other plug, I forgot torque wrench, only used common sense. torque tight enough I think should be ok.

My friends later told me, I am using a large torque wrench which only accurate on higher setting even it has lower setting in the mark. Also since I set high value on it entire time (mainly used for change tires) when you just set it back to low setting, the spring inside doesn't addjust in time. That might be the reason why I didn't hear 'click'.

After all, I highly suggest to use your common sense, do not rely on some fancy tool. My torque wrench is very expensive so I trust it wrongly :-(