Cutting open a transmission filter

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RegDunlop

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cutting open a transmission filter...?


anybody ever do it? I can't find any threads on BITOG or even pictures of any cut open..


Why?

It seems like as much as oil and oil filters are obsessed over is how much ATF and transmission filters are ignored.

Anybody got a story of one they cut open or pics of one?
 
when you say "nothing to note" do you mean in the construction of the filter or in what you found in the filter?

is it a similar filtering media to an oil filter or different?
 
They are not as sexy to do as oil filters....... Not a lot of contaminates like what are created inside of an engine.

I ran a rebuilt trans from 0 miles on Amsoil ATF to 80K miles. When I changed the fluid, pan filter, and opened up the Magnifine external filter I was thinking I could have gone about 130K on the fluid and filters they were so clean.

The fluid looked almost brand new.
 
It's a foam type material as opposed to oil filter's cellulose or synthetic material. According to another post on this forum the filtration level of transmission filters is in the 100 micron range which is ... pretty bad.
 
Originally Posted By: cmf
It's a foam type material as opposed to oil filter's cellulose or synthetic material. According to another post on this forum the filtration level of transmission filters is in the 100 micron range which is ... pretty bad.


bad as in 100 microns is big so it lets a lot of stuff pass through?

If it is a foam material wouldn't it start to break down over time and exposure to oil/atf?
 
Foam is a very general term. Foam can be made out of different substances with varying degrees of oil/atf resistance; you can safely assume the filter media in your transmission is resistant to oil/atf.

Here is a neat chart of the size of common things.

Purolator PureOne's first pass filtration is 50% 5 micron, 92.8% 10 micron, 99.2% 15 micron, 99.9% 20 micron for comparison (PureOne used for ease of access to information).

I think the ultimate summation should be that there are very few things produced in a transmission that are larger than 100 microns so the filters are really there to prevent catastrophically large particles from killing the transmission rather than keeping the fluid sparkly clean. ATF fluid also has it much easier than engine oil as the transmission is a closed system with no combustion byproducts.
 
The filters I cut open had a thick paper element folded in half, meaning it had two layers and one crease. There was nothing in either filter that I could see, Keep in mind a transmission doesn't contaminate it's fluid the way engine oil does with combustion by products, extreme temperatures, and dirt injection so it's not needing to filter that stuff out.
 
cmf- You said:"there are very few things produced in a transmission that are larger than 100 microns so the filters are really there to prevent catastrophically large particles from killing the transmission rather than keeping the fluid sparkly clean".

Your statement is mostly correct regarding transmission filtration. Several industrial transmission filtration studies have been conducted, which show that particles much smaller than 100 microns( many which a spin on filter will trap) get caught in valve bodies and solenoids causing failures. A good reason for something along the lines of bypass filtration!
 
Originally Posted By: AzFireGuy79
cmf- You said:"there are very few things produced in a transmission that are larger than 100 microns so the filters are really there to prevent catastrophically large particles from killing the transmission rather than keeping the fluid sparkly clean".

Your statement is mostly correct regarding transmission filtration. Several industrial transmission filtration studies have been conducted, which show that particles much smaller than 100 microns( many which a spin on filter will trap) get caught in valve bodies and solenoids causing failures. A good reason for something along the lines of bypass filtration!


I'm sorry if you thought that I considered particles smaller than 100 microns to be non-participants in transmission wear. I was merely commenting on the fact that stock transmission filters do not filter much because most of the particles produced are smaller than 100 microns.
 
do those small particles get caught in suspension? or do they settle out of suspension every time the transmission is not running

I'm asking because I'm wondering if more frequent fluid changes would help remove those particles?
 
Originally Posted By: tom slick
Anyone here having early transmission failures due to the lack of OE filtering? What about your last car? or the one before that?


What's early ? Malfunctioning or sticking valves are a common failure point and could be caused by contamination.

Bearing failures could be related to contaminate aggravated wear ?

Automatic Transmissions are as understandable as voodoo to most people. That they require fresh blood sacrifices routinely seems doesn't seem unreasonable.
 
Originally Posted By: PZR2874
^^Most trannys would benefit more from a flush as opposed to a "change"...


Please explain what that means to you and why you think that.

Are you talking about a cleaning fluid, a pressure assisted cleaning or just getting closer to %100 of the old fluid out.
 
Note that for over a year I attempted to find someone, ANYONE who used a "powered flush" or "pressure assisted" flush for auto trans service. Never found a single one and stopped looking after dozens of shops showed me their equipment.

Virtually everyone uses 'passive' machines that are nothing more than a bladder for new fluid and a container for old. Your trans pump does the work.

FWIW, we routinely run 9000 pound Savanas with 4l80E and 4L85E autoboxes for over 200k miles before rebuilding. One is still going at 400k miles!

All get a passive flush the first 30k miles and a trans filter/pan drop the next, alternating.
 
Originally Posted By: MonumentOiler
Originally Posted By: tom slick
Anyone here having early transmission failures due to the lack of OE filtering? What about your last car? or the one before that?


What's early ? Malfunctioning or sticking valves are a common failure point and could be caused by contamination.

Bearing failures could be related to contaminate aggravated wear ?

Automatic Transmissions are as understandable as voodoo to most people. That they require fresh blood sacrifices routinely seems doesn't seem unreasonable.


So you've had failures from "poor filtering" in-pan filters? Did the issues clear up when you put an aftermarket filter on? In your experience did the transmission last significantly longer because of the better filter?
 
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