Originally Posted By: bdcardinal
As far as the filter thing, if I am wrong, then I got bad info and I am sorry if I ruffled feathers. You do have to remember that people generally don't read the paperwork that comes with the trans that states the add in filter must be replaced with any trans service. All the proper maintainence is outlined in the paperwork that comes with the assembly. When I was an apprentice pulling these trans assemblies in and out the first step was to toss the customer portion of the paperwork on the passenger seat with a note that said "READ THIS" in as big as we could write.
Fair enough. I do agree that many people tends to ignore "special instructions" with their cars, even if emphasized by LARGE PRINT and verbal counseling sessions. I wrenched for a living once, including at Ford dealerships, and know how that works.
But that's a separate issue to the operation of the filter, however, and why I felt compelled to (vigorously) challenge your comments lest they leave people with an incorrect impression of Magnefine or Filtran inline transmission filters... both of which are good products.
To go into more detail on this, I don't have a figure on how much contamination a Magnefine (MF), or similar small filter, will hold before it begins to bypass. I know the standard change interval for a MF is 30K and likely that has a very large safety factor. The guy that designed the Magnefine gave me the impression that you could about double that interval on most cars but I won't speak for the company.
What follows below is something I worked out for a guy that was putting a P1 filter in as a trans filter (read it and then come back up here) and if we plugged in numbers for a filter that holds 80 percent less contaminants before the bypass is open (my educated guess for the MF), that would be a capacity of 2600 milligrams and dividing 2600 mg by the average mg/mile I calculated below (0.025 mg/1000mile), that works out to 104,000 miles before the filter is plugged and in full bypass.
Again, I don't have the actual holding capacity of the Magnefine, so it could be higher or lower. Also, if you were installing the Magnefine in a failed trans situation and had extra gunk in the system, you'd have to downgrade your estimate. Because the Magnefine has a magnet and will cat ALL the ferrous stuff before it reaches the filter, that both extends the interval for the filter element and increases the overall efficiency since 51 percent of the contaminants measured by Eleftherakis and Khalil were ferrous.
BTW, even if the filter element is plugged on a MF, and the filter is bypassed, the magnet is still catching that 51 percent of stuff that is ferrous.
Filter Calculations
On average, ATF in a trans that has never been serviced contains approximately 265 mg/l of contaminants after 70K miles of service, 90 percent of which are metallic. The particle sizes range from 5 to 80 microns, about 80 percent of them larger than 5u. Depending on the filter you use, let's say 15u absolute, you are only going to get a percentage of that percentage.
Here's a particle Count test from the trans of one of my trucks for context.
ISO Code (3) 18/17/14
>= 2 Micron 3257
>= 5 Micron 1206
>= 10 Micron 334
>= 15 Micron 129
>= 25 Micron 30
>= 50 Micron 3
>= 100 Micron 0
You are going to catch all the particles from 15u and larger and some of the smaller ones. As the filter loads up, it actually becomes more efficient (a process called sintering) so the filter gets better with age.
Ok, lets go back to that 265 milligrams per liter figure, an average developed by Engineers Eleftherakis and Khalil over decades of testing. If you have 12 quarts of fluid, that's about 11.3 liters so there is a total of about 2994 milligrams generated in 70K miles. Let's call it 3,000 mg. Divide that by 70K miles and that's .0429 mg/mile, which we'll call .043 mg/mile.
Let's say your filter can realistically catch 60 percent of that total amount, so that's .025 mg/mile. Purolater advertises their filters hold up to 13 grams of contaminants before the bypass opens, so lets use that figure.
Convert milligrams into grams and you have 13,000. 13,000/.025= 520,000. 520,000 miles to deliver a max load to a filter that can carry 13 grams. Cut it in half and you still are talking upwards of 250K miles. How many miles do you drive per year?
Consider also that you have eliminated the built in contamination as well as that which come from break-in, both of which are included in Eleftherakis and Khalil's 265 mg/l figure. They also state that 75 percent of a transmission's lifetime generation of contaminants come within the first 5K or so miles, so by changin the oil, you have greatly reduced the per mile generation of contamination.
As far as the filter thing, if I am wrong, then I got bad info and I am sorry if I ruffled feathers. You do have to remember that people generally don't read the paperwork that comes with the trans that states the add in filter must be replaced with any trans service. All the proper maintainence is outlined in the paperwork that comes with the assembly. When I was an apprentice pulling these trans assemblies in and out the first step was to toss the customer portion of the paperwork on the passenger seat with a note that said "READ THIS" in as big as we could write.
Fair enough. I do agree that many people tends to ignore "special instructions" with their cars, even if emphasized by LARGE PRINT and verbal counseling sessions. I wrenched for a living once, including at Ford dealerships, and know how that works.
But that's a separate issue to the operation of the filter, however, and why I felt compelled to (vigorously) challenge your comments lest they leave people with an incorrect impression of Magnefine or Filtran inline transmission filters... both of which are good products.
To go into more detail on this, I don't have a figure on how much contamination a Magnefine (MF), or similar small filter, will hold before it begins to bypass. I know the standard change interval for a MF is 30K and likely that has a very large safety factor. The guy that designed the Magnefine gave me the impression that you could about double that interval on most cars but I won't speak for the company.
What follows below is something I worked out for a guy that was putting a P1 filter in as a trans filter (read it and then come back up here) and if we plugged in numbers for a filter that holds 80 percent less contaminants before the bypass is open (my educated guess for the MF), that would be a capacity of 2600 milligrams and dividing 2600 mg by the average mg/mile I calculated below (0.025 mg/1000mile), that works out to 104,000 miles before the filter is plugged and in full bypass.
Again, I don't have the actual holding capacity of the Magnefine, so it could be higher or lower. Also, if you were installing the Magnefine in a failed trans situation and had extra gunk in the system, you'd have to downgrade your estimate. Because the Magnefine has a magnet and will cat ALL the ferrous stuff before it reaches the filter, that both extends the interval for the filter element and increases the overall efficiency since 51 percent of the contaminants measured by Eleftherakis and Khalil were ferrous.
BTW, even if the filter element is plugged on a MF, and the filter is bypassed, the magnet is still catching that 51 percent of stuff that is ferrous.
Filter Calculations
On average, ATF in a trans that has never been serviced contains approximately 265 mg/l of contaminants after 70K miles of service, 90 percent of which are metallic. The particle sizes range from 5 to 80 microns, about 80 percent of them larger than 5u. Depending on the filter you use, let's say 15u absolute, you are only going to get a percentage of that percentage.
Here's a particle Count test from the trans of one of my trucks for context.
ISO Code (3) 18/17/14
>= 2 Micron 3257
>= 5 Micron 1206
>= 10 Micron 334
>= 15 Micron 129
>= 25 Micron 30
>= 50 Micron 3
>= 100 Micron 0
You are going to catch all the particles from 15u and larger and some of the smaller ones. As the filter loads up, it actually becomes more efficient (a process called sintering) so the filter gets better with age.
Ok, lets go back to that 265 milligrams per liter figure, an average developed by Engineers Eleftherakis and Khalil over decades of testing. If you have 12 quarts of fluid, that's about 11.3 liters so there is a total of about 2994 milligrams generated in 70K miles. Let's call it 3,000 mg. Divide that by 70K miles and that's .0429 mg/mile, which we'll call .043 mg/mile.
Let's say your filter can realistically catch 60 percent of that total amount, so that's .025 mg/mile. Purolater advertises their filters hold up to 13 grams of contaminants before the bypass opens, so lets use that figure.
Convert milligrams into grams and you have 13,000. 13,000/.025= 520,000. 520,000 miles to deliver a max load to a filter that can carry 13 grams. Cut it in half and you still are talking upwards of 250K miles. How many miles do you drive per year?
Consider also that you have eliminated the built in contamination as well as that which come from break-in, both of which are included in Eleftherakis and Khalil's 265 mg/l figure. They also state that 75 percent of a transmission's lifetime generation of contaminants come within the first 5K or so miles, so by changin the oil, you have greatly reduced the per mile generation of contamination.
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