[cerritos]

The transmissison fluid drain plug gasket is a copper gasket. What's the difference between a copper gasket and an aluminum crush washer?

I can see the aluminum crush washer is squeezed and deformed to form a seal, but this does not seem to be the case for a copper wahser. Why is copper material used?

 

[Kajtek1]

both copper and aluminum are way softer than the steel. Aluminum is cheaper material, but with the size of washer that should not affect the final price. It might be the producer access to the material that makes final design.

 

[cerritos]

So, copper washer can also be crushed to form a seal.

Any benefit of using copper?

 

[Check Codes]

None I can think of. Both are malleable and personally I wish they'd use aluminum, since we need copper for wiring and it's already expensive enough.

 

[Kajtek1]

Personally I prefer copper, since it is more reusable. I know, crush washers should not be reused, but I am not to drive 1 hr to pick up a washer when I do the job. Pure aluminum is very soft, so it might seal dirty connection better, but than it will mushroom under bigger torque.

 

[PLeeson]

I can't see that the milligrams of copper in the typical washer will affect commodity prices.

I've only seen copper used on my cars.

 

[Kajtek1]

thieves are cutting copper cables under 14,000 volts, my friend had his catalytic converter stolen at metro parking lot (security patrol) for few grams of platinum in it.
Soon we might see oil floating down the parking lots when thieves will steal the copper washers for the scrap value.

 

[Check Codes]

Personally I prefer copper, since it is more reusable. I know, crush washers should not be reused, but I am not to drive 1 hr to pick up a washer when I do the job.

With my first order from Autohausaz.com, I ordered several, they were like .13 each. Came right to my door, didn't have to drive anywhere.

 

[Kajtek1]

the cars that need washers have them included with filter kit.
W210 is design for suction oil change

 

[G-AMG]

I have found it odd that the SAME bolt for the Transmission Pan, AND Torque Converter, use a different Sealing ring.

The T/C is Aluminium, the Pan Copper.

Go figure...

 

[Dave1965]

I have found it odd that the SAME bolt for the Transmission Pan, AND Torque Converter, use a different Sealing ring.

The T/C is Aluminium, the Pan Copper.

Go figure...

OBVIOUSLY because the T/C is a rotating part. The Aluminum washer being a lighter material wouldn't affect the dynamic balance as much as the heavier Copper variety.

I'm just kidding, of course...

Maybe the materials differ because the T/C and Transmission Pan were simply sourced from different vendors?

 

[Kajtek1]

the balancing is no joke. You might think that few grams weight difference is marginal, but think 6000 rpm on about 10 cm radius.
what class physics were about calculating centrifugal force?

 

[G-AMG]

C'mon... I can't believe there is even Centigram differences between the two....

 

[Kajtek1]

copper is about 3 times heavier by the volume than aluminum. anybody having spare washer that he can weight?

 

[Mick D]

Another fact that would be as equally irrelavent is that Al is extremely reactive while in contact to disimilar metals. Galvanic corrosion occurs when an electric current flows between the metals and the Al will be consumed.

 

[cerritos]

Could it because that the torque converter is aluminum alloy and transmission fluid pan is steel?

Dealership replaced my transmission drain bolt (for whatever the reason is, most likely it was damaged). The replacement is a steel type bolt and not an aluminum alloy type.

http://www.npl.co.uk/upload/pdf/bimetallic_20071105114556.pdf

Copper vs Aluminum crush washers - NSX Prime

 

[Kajtek1]

Another fact that would be as equally irrelavent is that Al is extremely reactive while in contact to disimilar metals. Galvanic corrosion occurs when an electric current flows between the metals and the Al will be consumed.

consumed is exaggeration. Actually copper in real life is more aggressive metal than aluminum. It is the copper connected to galvanized pipes in our houses that cost lot of leaks (I make quite a good living on the fact) and it is copper combined with aluminum that cost long term problems. Nothing sudden -those owners of W123 who put aluminum fuses into brass holders drove for over a year before whole hell got loose.
Is the converter made with aluminum? I was under the impression they are stamped steel.

 

[JPMose]

I know I am late in the game.....the aluminum washer crushes easier and it is less of a load on the alum. torque converter drain threads when tightening the bolt. It is much easier to strip the threads on aluminum versus steel (hence the copper washer for the pan and alum for the torque converter). This is what my mechanic told me when I asked for advice years ago on doing my own fluid change on my 722.3 transmission (for a 1983 300SD and 1987 560SL).

 

[e-420]

I have found it odd that the SAME bolt for the Transmission Pan, AND Torque Converter, use a different Sealing ring.

The T/C is Aluminium, the Pan Copper.

Go figure...

another consideration is what the metal is the washer is crushing against. You want a good seal AND as close as possible similar metals. Pan is steel, copper is close in the electric potential, hence low chance of galvanic action. Also, it is easier to get a good seal with the aluminum, and the TC bolt is smaller IIRC and lower torque.

TC I think is not steel, possbily aluminum, hence aluminum crush washer. Copper and Aluminum are not the best of friends for galvanic action.

 

[summicron]

AFAIK spark plugs have "crush washers". Not the same as the solid washers used for drain plugs.