Real transmission filter - not the strainer in the pan

Jhelms

New member
Did a search and did not find much for the 4runner on this topic. After a tear down this weekend (pan removal and cleaning / cleaned screen / magnets / and re-seal, I observed a lot of normal sediment / film in the bottom of the pan (normal for a car with no dedicated filter)

The screen itself is really not a filter. It just fine enough to block potentially damaging particulates from entering the transmission. Generally my cars that have had a dedicated transmission filter (not just a screen strainer) do not show near the amount of film / buildup on the magnets or strainer assembly as the 4runner had.

The general killers of auto trannies are:
- Heat / breakdown of the transmission fluid
- Contaminated / dirty fluid
- Blocked filters or strainers (kills off more RX300 trannies / 1mzfe trannies than imaginable)


In short, I will be installing in-line transmission filters that go just after the cooler on the return line. Just as preventative maintenance - hope to help extend the transmissions life and help eliminate flow issues through the screen over time and buildup / contamination of the fluid.

I am going to try out the magnefine 3/8" inline filters and see how the filter media and magnet looks after a bit. I will drain a small jar of fluid before installing the filter and then after it has been run for a while to see if the clarity improves as well.
Magnefine 3/8 Inch Magnetic Inline Transmission Filter


Here are some photos of my teardown this weekend. Again, nothing abnormal for a car with just a screen strainer.

In this photo, you can see the strainer assembly in the pan. Notice the blackish coloring on the sides and you can see where I wiped it off the surface of the strainer assembly (large rectangle thing with the oval hole)
TP3.JPG


Here you can see particulate buildup in the screen. Normal for a car with 230K miles that has never had a screen change. But not a good thing.
TP4.JPG


Here is the strainer after it was thoroughly cleaned / flushed and back flushed over and over
TP7.JPG

TP8.JPG


Some of the magnets from cleaning the pan. The bottom two were cleaned, the top was not. Again normal but not desirable of course.
TP5.JPG




Wish I had more pics before I wiped the pan down and the strainer. I am thinking a quality inline filter may really help the overall life of our transmissions as they are only about $16 ea and the filter is replaceable. Also it will help keep the screen clean and pan clean. Cannot hurt anyways.
 
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That's what i've used for about 100k so far, changed it at about 50k, fluid drains out red and translucent as ever. :cowboy:

Good stuff man! Any issues with them? leaks or other? Several options for a real filter but the magnefine looks to be my best option - a great option all around
 
I've had one on mine for about 3k miles with no leaks. Previous owner never changed the fluid or screen in over 200k miles so I'm leery to change the fluid but I can at least filter the it better.
 
Good stuff man! Any issues with them? leaks or other? Several options for a real filter but the magnefine looks to be my best option - a great option all around

No issues whatsoever. Can't go wrong installing it, has an arrow for direction flow. I find them on ebay for about $12, so yeah really cheap insurance. Luck!.
 
I've had one on mine for about 3k miles with no leaks. Previous owner never changed the fluid or screen in over 200k miles so I'm leery to change the fluid but I can at least filter the it better.

Good stuff! Did you drop the pan and clean it / change or clean the strainer?

If so, I would not be worried about changing the fluid.

If you have not dropped the pan and done a thorough cleaning... then I would be leary of doing a flush too. All the gunk in the pan and on the magnets can cause issues if dislodged - or stirred up.
 
I haven't touched the pan. And I won't flush it either. At best just drain the pan, replace the screen, and refill with clean fluid. All moot though because at this point it's almost a guarantee that the only thing holding the transmission together is the dirty fluid. Last time I did a fluid swap on a transmission that had this many miles and hadn't been taken care of it went from working great to slipping in 2 weeks.
 
I haven't touched the pan. And I won't flush it either. At best just drain the pan, replace the screen, and refill with clean fluid. All moot though because at this point it's almost a guarantee that the only thing holding the transmission together is the dirty fluid. Last time I did a fluid swap on a transmission that had this many miles and hadn't been taken care of it went from working great to slipping in 2 weeks.

To each his own. I have done them recently at 250K miles, 230K miles and 220 in different cars. very soon on my other 4runner at close to 220K as well. In the past I have done many at 200K+ miles without issue. If done properly, all the stuff that CAN damage the transmission is in the pan, on the magnets or clogging the screen. Drop the pan and remove all the crap, fill with fresh fluid and you are ready to rock :thumb3: Notice, this is not a flush, but a drain and fill. If a transmission is actually "gummed up" then you have another world of issues :D
 
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I haven't touched the pan. And I won't flush it either. At best just drain the pan, replace the screen, and refill with clean fluid. All moot though because at this point it's almost a guarantee that the only thing holding the transmission together is the dirty fluid. Last time I did a fluid swap on a transmission that had this many miles and hadn't been taken care of it went from working great to slipping in 2 weeks.

My dad had a similar story. Maintenanced my mom's straight 6 Dart back in the day, had gummed up valve cover and all this sludge from lack of changes. Cleaned it all out and put in fresh fluid, never ran the same way again.
 
I haven't touched the pan. And I won't flush it either. At best just drain the pan, replace the screen, and refill with clean fluid. All moot though because at this point it's almost a guarantee that the only thing holding the transmission together is the dirty fluid. Last time I did a fluid swap on a transmission that had this many miles and hadn't been taken care of it went from working great to slipping in 2 weeks.

I've heard this forever, and I have yet to hear a reasonable explanation for why it would be true.

Dirty fluid isn't good for anything in a hydraulic system, and there's no way it's holding anything together in one.
 
I haven't touched the pan. And I won't flush it either. At best just drain the pan, replace the screen, and refill with clean fluid. All moot though because at this point it's almost a guarantee that the only thing holding the transmission together is the dirty fluid. Last time I did a fluid swap on a transmission that had this many miles and hadn't been taken care of it went from working great to slipping in 2 weeks.

I am racking my brain trying to figure out how a fluid swap could cause what you describe. How did you swap the fluid?
 
From the multiple shops I've talked to about this, the older the fluid gets the grittier it gets from clutch fibers and general wear. If not replaced regularly eventually the clutches wear out to the point that the only thing keeping the transmission from slipping is the grit in the fluid. Swap the fluid out for clean fluid and the grit is gone and the clutches can slip. Makes sense in my head and having experienced it first hand, I'm not changing the fluid in mine.

And for the record, when I experienced this I dropped the pan, replaced the filter, reinstalled the pan, and refilled it. 2 weeks later I was buying a $6000 transmission.

And I'm not worried about the mileage it's at, I'm worried because it hasn't been changed ever in 220k miles. At least not from what I can find record wise. And judging by the color it hasn't been done in at least the last 100k. But if y'all are willing to donate for a new trans I'll try it tomorrow HAHA
 
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From the multiple shops I've talked to about this, the older the fluid gets the grittier it gets from clutch fibers and general wear. If not replaced regularly eventually the clutches wear out to the point that the only thing keeping the transmission from slipping is the grit in the fluid. Swap the fluid out for clean fluid and the grit is gone and the clutches can slip. Makes sense in my head and having experienced it first hand, I'm not changing the fluid in mine.

And for the record, when I experienced this I dropped the pan, replaced the filter, reinstalled the pan, and refilled it. 2 weeks later I was buying a $6000 transmission.

And I'm not worried about the mileage it's at, I'm worried because it hasn't been changed ever in 220k miles. At least not from what I can find record wise. And judging by the color it hasn't been done in at least the last 100k. But if y'all are willing to donate for a new trans I'll try it tomorrow HAHA

Indeed - it is a tale that is told by a lot of mechanics. And each that I ask... well did it happen to you? I get.. NOPE, read about it, or heard someone that knew someone, whos brother had it happen at another shop.

Totally possible but for that level of grit to be present, the screen would be clogged and the transmission would be virtually toast if it needs contaminants to "hang on"

Only thing I can think of is the wrong fluid was used, the tranny was on its way out, excess gasket material was used which got into the tranny or other contaminant. Or heck, it is what some claim and it caused an issue.

I just shed caution to internet gossip and tales from shops or friends. And I for SURE would not tell someone to skip servicing their transmission that has over 200K because their old fluid is the only think keeping it going. And I have never seen an clutch pack from an auto transmission that was fiber based.

And what in the world tranny cost you $6k? lol good lordy man! I am sure it did but wow... some dealer took the crew out for dinner after that purchase :D :cheers:
 
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It was for a diesel. Base trans was $4000 and I had them add in $2000 worth of upgrades since it was out and I was getting ready to crank up the torque to quadruple digits.

And +4 was used (factory recommended) and no gasket maker (used factory gasket).

I get the internet rumor but seeing as how it failed so soon afterwards doing it myself I'm hesitant to recommend doing it. Again, it's not the mileage on the trans, it's the mileage on the fluid that bothers me.
 
where did you mount yours ?
I forgot that I had one on a shelf at my sons. Need to put it in. Should have done it when I installed my cooler. What was I thinking ? guess its just old timers. Will have to do it next week when Im at my sons
 
And for the record, when I experienced this I dropped the pan, replaced the filter, reinstalled the pan, and refilled it. 2 weeks later I was buying a $6000 transmission.

Indeed - it is a tale that is told by a lot of mechanics. And each that I ask... well did it happen to you? I get.. NOPE, read about it, or heard someone that knew someone, whos brother had it happen at another shop.

Totally possible but for that level of grit to be present, the screen would be clogged and the transmission would be virtually toast if it needs contaminants to "hang on"

Only thing I can think of is the wrong fluid was used, the tranny was on its way out, excess gasket material was used which got into the tranny or other contaminant. Or heck, it is what some claim and it caused an issue.

I just shed caution to internet gossip and tales from shops or friends. And I for SURE would not tell someone to skip servicing their transmission that has over 200K because their old fluid is the only think keeping it going. And I have never seen an clutch pack from an auto transmission that was fiber based.

And what in the world tranny cost you $6k? lol good lordy man! I am sure it did but wow... some dealer took the crew out for dinner after that purchase :D :cheers:


I suspect that in most of these instances the transmission was having problems, and that's what prompted someone to service it in the first place. At that point it was so far gone a fluid change wasn't going to do anything for it, but the last thing that was done to it gets the blame for the failure.

I've worked with hydraulic systems for a lot of years (and overhauled several automatic transmissions when I was a broke young man), and dirt is never good. Even if the grit was aiding the clutches it would be killing all the spools in the valves, the pump, and the regulators. The clearances on those components is very tight, to the point where a lot of the surfaces are ground rather than machined.
 
Those Magnefines have been out of stock for quite a while on Amazon, should they come back best to order at least two :)
 

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