I've changed the ATF in my '08 CR-V twice now, and both times the drain plug had a thin layer of gray slime covering it. Now I'm guessing if there's a magnet there, then it's supposed to collect fine stuff, presumably steel, that doesn't get caught in the filter. So what is that from, mostly? Is it bits and pieces of clutches and whatever the clutches grab, or is it parts of gears and bearings? I changed to Mobil 1 ATF and I'm curious to see if it makes any difference in the amount of stuff on the magnet.
Magnetic drain plug questions
- Thread starter Dave Sherman
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Get a Magnefine, best thing ever made for transmissions.
normal stuff. There are a variety of drums, splined shafts, thrust bearings, etc that are in constant motion and will always produce a small amount of wear material. That's why the mfg put in that magnetic tipped drain plug.
Clutch material is fibrous so you would find that as very fine debris in the pan. Clutch discs are steel but usually they don't produce a lot of stuff. Remember that if the tranny is equiped with a filter CHANGE IT! It's there to provide additional protection to the electronic shift and pressure solenoids plus of course to catch the larger debris in the fluid.
The good thing is that you are changing the fluid, I don't see any problem with what you found.
Clutch material is fibrous so you would find that as very fine debris in the pan. Clutch discs are steel but usually they don't produce a lot of stuff. Remember that if the tranny is equiped with a filter CHANGE IT! It's there to provide additional protection to the electronic shift and pressure solenoids plus of course to catch the larger debris in the fluid.
The good thing is that you are changing the fluid, I don't see any problem with what you found.
Mud is correct; no need to worry.
Originally Posted By: Dave Sherman
I've changed the ATF in my '08 CR-V twice now, and both times the drain plug had a thin layer of gray slime covering it. Now I'm guessing if there's a magnet there, then it's supposed to collect fine stuff, presumably steel, that doesn't get caught in the filter. So what is that from, mostly? Is it bits and pieces of clutches and whatever the clutches grab, or is it parts of gears and bearings? I changed to Mobil 1 ATF and I'm curious to see if it makes any difference in the amount of stuff on the magnet.
Automatic transmission clutches are multi-plate clutches where there's a stack of disks with friction material (like clutch or brake material except designed to work in oil) mixed every-other-disk with plain steel disks. The steel disks shed very fine particles.
Older automatics also have bands and drums where the band has friction material and the drum is a steel shell, which also sheds.
The gears are hard steel which shed much bigger particles, though not usually as big and "chippy" as rear end gears or manual transmissions. Those get caught in the filter, but sometimes drop off the filter to the bottom of the pan when you shut the engine off. They then can get stuck to the magnet.
Hope this helps!
I've changed the ATF in my '08 CR-V twice now, and both times the drain plug had a thin layer of gray slime covering it. Now I'm guessing if there's a magnet there, then it's supposed to collect fine stuff, presumably steel, that doesn't get caught in the filter. So what is that from, mostly? Is it bits and pieces of clutches and whatever the clutches grab, or is it parts of gears and bearings? I changed to Mobil 1 ATF and I'm curious to see if it makes any difference in the amount of stuff on the magnet.
Automatic transmission clutches are multi-plate clutches where there's a stack of disks with friction material (like clutch or brake material except designed to work in oil) mixed every-other-disk with plain steel disks. The steel disks shed very fine particles.
Older automatics also have bands and drums where the band has friction material and the drum is a steel shell, which also sheds.
The gears are hard steel which shed much bigger particles, though not usually as big and "chippy" as rear end gears or manual transmissions. Those get caught in the filter, but sometimes drop off the filter to the bottom of the pan when you shut the engine off. They then can get stuck to the magnet.
Hope this helps!
Originally Posted By: millerbl00
Get a Magnefine, best thing ever made for transmissions.
+1
Or on the cheap use a Diesel Fuel Filter that uses a wire-mesh screen like I did in my Auto-Rx Engines/Transmissions thread.
Get a Magnefine, best thing ever made for transmissions.
+1
Or on the cheap use a Diesel Fuel Filter that uses a wire-mesh screen like I did in my Auto-Rx Engines/Transmissions thread.
The very fine powder is most likely from the metal clutch plates.
This is almost inevitable.
This is almost inevitable.
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