Hi,
Stupid question but while at the dealers, I asked how "important" it is to use a brand new washer for the oil and the transmission drain plug because one reference I have, mentioned to use a new washer, every single time you change both but gave no reason why. ($3.00 each at the Honda dealer) His response was to use a new washer "when the old one leaks". I, knowing very little about all this stuff, had it in the back of my mind that the washer was there to "secure" the bolt, so it wouldn't loosen. Is the only reason for these aluminum crush washers for keeping the fluid from leaking?? (And I'm going to stock up on these through RockAuto) And while we're at it-----with 115K on my Fit, would it be advisable to buy a new, magnetic drain plug for the auto tranny? Do these magnets wear out with use? Thanks for any clarification.

 

Aluminum washers deform to make a seal when the bolt is tightened (hence "crush"). They won't make a seal when the bolt is loosened and tightened again. They are designed for single use.

 

Thanks for that info. Just ordered a slew of oil drain washers and a new bolt/washer for my auto tranny from Rock Auto.

 

If you look on new washer you will see one side of it is flat when other is rounded at edges. To avoid future leaks, install the flat side toward the engine pan or transmission housing and rounded toward the base of the drain bolt head

 

Yes, I noticed that! Will do when installing the next time! Thank you.

 

I never noticed that -- thanks for posting the tip!

 

I feel like that tip would be obvious looking at the washer ... But I also can't say WHY it would be obvious. I would just not want to put it the other way.

 

I've also reused the washers, I would wait until they leak.

Regarding the magnet. I believe it does not wear out. Hope someone will correct me if in am wrong.

 

Well, when I get my new transmission plug I will let you know if one magnet "feels" stronger than the other----after using the old one for 115K. I don't really think there is going to be a difference unless it's a manufacturer difference in quality of magnets. At any rate, I will post. No sense in buying a new one if there's no difference in magnetic "strength".

 

The dealer replaces them with every oil change because at their cost its is less hassle then having a customer coming back in with an oil leak. Same as most dealer bill out a can of brake clean to the tech for a oil change to make sure there is no oil left under the car that could drip.
I keep one in my tool box and only replace it if I notice any weeping between oil changes.

Aluminum washers crush when tightened and work harden which causes them to become brittle. Copper washers can be heated till red hot and allowed to cool and reused but not aluminium.

Magnets really only wear out if heated to the point your transmission will have failed long before the magnet does.