The Racor can be mounted in any convenient spot. It comes with a bracket, but we found a s
What Can You Do?
The one obvious method of removing contamination is to change the lubricant, but there's a hitch. A high percentage of the time, you're draining and wasting perfectly good transmission fluid. That's hard on the wallet, the global resource bank, and the environment. Fluid changes have been made more difficult in recent years because you can only drain 30 to 40 percent of the total fluid volume in the trans. (Penny-pinchers at the OEMs eliminated converter drain plugs years ago.) Fluid exchanging machines can take you a good part of the way in that regard, but leave accumulated wear materials in the pan if it's not dropped, cleaned, and the filter replaced.
Experts in contamination think the very first change is the most important to remove the Type 1 contamination. It can amount to as much as 75 percent of the accumulated material generated in the life of an automatic. Some experts even advocate a change (including pan drop and filter) within the first 100 miles for that reason, but if you change it within 5,000 miles, you get the chance to eliminate the break-in material, too. After that, you can follow the factory interval according to driving conditions.
Another option is to introduce an external filter into the equation. These filters are usually installed in the transmission cooler circuit, which directs a certain amount of hot oil out of the converter for cooling. This is only a percentage of the total oil flow in the trans, but an inline filter will eventually clean the oil and keep it that way.
Now we'll introduce you to filtration products from two well-known manufacturers. We had the opportunity to test both products and verify their efficiency via oil analysis.
The Magnefine is a small inline filter that comes with either a billet aluminum or Nylon 66 housing. It inserts into the cooler line and is offered to fit 5/16-, 3/8- and 1/2-inch OD line. It contains a 35-micron filter (nominal) but also a magnet. With approximately 51 percent of contaminant particles being ferrous, it will catch nearly all of those, regardless of size. A bypass valve prevents the unit from plugging up and decreasing cooler line flow. Boss Products recommends a 30,000-mile service interval for this filter.
The Magnefine was developed in Australia by Boss Products and underwent significant testing there. When introduced to North America, it was offered both to the OEMs and the aftermarket. The aftermarket glommed on instantly. After putting them through a battery of qualification tests, Ford and Chrysler gave them part numbers, but some other OE manufacturers use them as well.
Blackstone Labs, of Fort Wayne, Indiana, did our contamination analysis. Here, Ryan Stark
The cooler line is cut and the Racor is spliced inline using the hoses with special ferule
The Magnefine was pure simplicity to install on the F-150's power steering line. The truck
The Ford and Mopar in-house misers didn't go quite so far as letting them install them on all new cars or trucks, but mandate their use when a remanufactured automatic is installed. That prevents contaminants trapped in the cooler from the initial failure, or Type 1 material from the rebuilding process, from killing the new trans.
You can use the Magnefine on power steering systems as well. Installing it on the return hose can significantly increase power steering life. According to Boss Products, it has been especially beneficial to reducing leakage in rack and pinion steering systems.
Our test mule for the Magnefine was an '05 Ford F-150, with a 5.4L V-8 and 4R75E electronically controlled automatic and rack-and-pinion steering. The truck was showing about 15,000 miles at the start of the test. The transmission fluid had been replaced at 11,000 miles with Royal Purple Max ATF. At the time of the change, which was done as a break-in change, it was noted that the pan magnet was loaded up with Type 1 debris. That observation inspired this article.
After taking an oil sample, we installed the Magnefine on the cooler return line and took the final oil samples at 2,269 miles. The initial sample was a very clean 15/12 ISO code, and we worried about seeing a noticeable change. Those very good numbers were due to the fresh oil and the SPX Filtran pan filter that was replaced at the oil change. Filtran uses MicroFelt media which delivers a better-than-average 80 microns nominal rating and would give you a small edge over the average "bargain" filters, many of which Filtran claims are 100- to 150-micron at best. Our fears about the Magnefine were unfounded. It dropped the ISO Code down to a squeaky-clean 12/9 by the end of testing.
We also installed a Magnefine into the return line of the rack and pinion steering and ran it for 552 miles before resampling the oil. The ISO code dropped from a dirty 20/17/12 to a clean 17/15/12. Similarly, when installed into the long-overdue-for-an-oil-change power steering of our '86 test rig, it dropped the code from a filthy 21/18/14 to 18/16/13 in just 289 miles.