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1998 e430
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sorry to dig up an old thread but, i did a fluid / filter change on my '98 e430 this weekend and there was no magnet, this thread seems a good a place as any...

given it was probably this way for years and i didn't want to put any 'ol magnet there, i just put everything back together. what would you folks recommend for the next fluid change?
 

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^^^Remembering a bunch of threads from the past, I recall that most people never find anything meaningful on their magnet, assuming they bother to install one. Most of the particles that end up in the pan in this transmission aren't ferrous, so the magnet doesn't do anything except get dirty.

To me it's an easy decision. If it makes you sleep better knowing there is a magnet in there, then by all means put one in. It certainly won't hurt anything.

Hope that helps...at least some. ;)

Good luck.
 

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Don't heavier particles sink to the bottom of the pan with or without a magnet anyway?
The ones that don't get pulled into and trapped in the filter, yes.

But a magnet doesn't attract "heavier" particles, it attracts *ferrous* particles: those with iron in them. And the vast majority of the things that show up in the pan are not ferrous.

That's kind of the whole point. The magnet doesn't really do that much in these transmissions (and when it does, there's not a lot you can do at that point). But if it makes someone feel better to have it, then why not?
 

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Outstanding Contributor - Always Remembered, RIP
Zotye Auto 1.5T T600 2016
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The ones that don't get pulled into and trapped in the filter, yes.

But a magnet doesn't attract "heavier" particles, it attracts *ferrous* particles: those with iron in them. And the vast majority of the things that show up in the pan are not ferrous.

That's kind of the whole point. The magnet doesn't really do that much in these transmissions (and when it does, there's not a lot you can do at that point). But if it makes someone feel better to have it, then why not?
By the time the magnet starts picking up ferrous metals the tranny is shot anyway, because it means either the center bearing is about to collapse or the hard plates are wearing badly, in which case the soft plates would be almost none existant.

All the magnet does is inform the mechanic he must talk to the customer and tell him his tranny is shot.
 

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sorry to dig up an old thread but, i did a fluid / filter change on my '98 e430 this weekend and there was no magnet, this thread seems a good a place as any...

given it was probably this way for years and i didn't want to put any 'ol magnet there, i just put everything back together. what would you folks recommend for the next fluid change?
Most of wearing metals on those transmissions are aluminium that get filtered by the strainer.
I noticed that few steel shavings like to stick to speed sensor magnets and eventually might fool the sensor.
Have a feeling that lot of electric plates are replaced just becouse of those shavings, so cleaning the sensor magnet is on my list.
 

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1999 W210 E300, green, 148k mi. (Feb2016) (sold Sep2018, 163k)
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I had our built-in microwave oven (circa 1996) die this summer. It took me a while to figure out, but while the magnetron is said to be a low-failure item in most microwave ovens, that was the failed part. Of course, it took out the relay's contacts and blew a NLA thermal fuse in the process, but it's all working fine now. I turned it into a fun project by replacing the cube relay with a hefty solid state relay, just because I had one and needed to use it somewhere ;)

A microwave magenetron is basically a vacuum tube with a couple of powerful ring magnets. Guess what's on my 'frig door right now: two magnets that look identical to the one above. They're not wimpy, either.
 

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1998 e430
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thanks for all the input! i'll plan my next fluid / filter change in 30k or so and see if i can't dig up the old style mesh magnet from a local wrecker in the meantime.

given it's survived this long w/o, it should be fine.
 

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1999 E320, 2001 E320, 2004 S430
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A microwave magenetron is basically a vacuum tube with a couple of powerful ring magnets. Guess what's on my 'frig door right now: two magnets that look identical to the one above. They're not wimpy, either.
Do all microwave oven have these ring magnets? similar size/thickness to the one used in the transmission pan?
 

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1998 e430
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i too have some old magnets but, i worry as they seem brittle with little bits flaking off the edges...

i also wonder if a weak one wouldn't wander around the pan and possibly interfere with something.
 

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1999 W210 E300, green, 148k mi. (Feb2016) (sold Sep2018, 163k)
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Ceramic magnets tend to brittle. If you bang them, yes, pieces come off. But they're magnets too! They're not going to go far, certainly not "float" up to contact something ferrous and moving, nor migrate into the filter.

Many magnets lose strength when exposed to high heat, but <300°F isn't considered high heat in this application.

I do not know if all microwave magnetrons have ring magnets, but I assume probably yes.

I would have no qualms putting one of these into my AT pan. They're 1/2" thick and the larger dia. one is 2-1/4". They don't want to come off my freezer door without a good, solid pull -- they have lots of surface area to bond to the AT pan, and to hold ferrous nuggets, should any exist.

I have some tiny (3/8" dia) rare-earth magnets that I use for some tasks, but these salvage magnetron magnets are like trailer park trash relatives of what MB's selling.


Standard disclaimer: Microwave ovens have a large HV electrolytic capacitor connected to the magnetron tube. Do not touch magnetron wiring unless you are certain (certain!) that the capacitor has discharged. You cannot test for this with a conventional voltmeter. Many modern magnetron circuit designs incorporate a bleed resistor, but this is not universal. Yes, you can kill yourself working on a microwave oven. The working voltage of a magnetron can be 5000 volts.
 

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