Reusing transmission filter. Opinions.

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Sep 30, 2013
My plan is to do a drain and fill every year. I drive around 12-15k a year. Jeep recommends a drain and fill every 30k after 100k IIRC so I'm assuming that is what the filter is rated for.

Should I just remove the fluid from the filler tube and change the filter every other year? It would of course save money on the filter ($10.. big whoop), but also save time on removing the pan and dealing with the mess. I would also assume as mileage increases on the filter, so does its efficiency so it would be pointless to remove early.

I had to do a drain and fill 6 months apart last spring because of a leaking pang gasket. I would loose around a half a quart of fluid per week.. it was bad. The filter looked new and the pan magnet had little to no sludge whatsoever. Fluid has been changed w/ filter at 100k, (pre BITOG exposure period
) 145k and 155k.

*Just realized my mileage and month math doesn't add up. It would have had to have been less than 10k between fills. Drained it Sept. 2013 and May 2014. I need to keep a log book!
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Awesome. Ill just be sure not to get the siphon hose stuck down in the filler tube like last time. Lol.
Most in the pan filters are 'rock catchers'.

I'd install an in-line A/T filter (like a Magnafine) and change it every 30K. The in the pan filter should be good for 100K.
I would probably do that method after doing one complete pan/filter service. That would allow you to get the magnets and filter clean from the original manufacturing process. I just did my Silverado at 36k and there was quite a bit of metal on the magnets.
If you're planning on keeping it for several more drain/fill intervals I would say:

Do a full flush -- disconnect both cooler lines, put return in a bucket/jug of new fluid, put pressure line in an empty bucket. Start engine, shift between 1st/reverse, monitor fluid color coming out of cooler line. When fluid looks clean, or you have run about 10 qts through, lift the return line out of the new fluid and let the trans pump continue to pump out about another 2 qts. Shut down, drop pan (that's where the 2qts low comes into play -- reduces mess), replace filter, clean pan & magnet(s), install aftermarket pan drain plug, reassemble & top off with fluid.

Now you have a handy drain plug for your yearly drain & fill! Install an auxiliary trans filter if you want to, change auxiliary trans filter as often as makes you sleep well at night.
There is a big difference between a rock catcher and a typical in pan filter. A rock catcher in my book is the in-pan filter on my early Torq-shift. It is a fine metal mesh. The oil is actually filtered with a bypass filter in-line to the cooler. Trans filters with actual media really do something, although not near as much as a Magnafine. Personally, I do change them when I drop the pan, usually around 30-40K, although I just did a new to me Grand Caravan with 110K on it. As long as the pan is off, why not change the filter? They cost like $10, might as well do it. If, like the OP you are siphoning between pan drops, then by all means don't sweat it! I do like the mangnafine idea though. I have been considering using one for years on vehicles other than my F250. With the factory bypass, I think a magnafine would be redundant on that one. I understand the guys who flush transmissions, it just aint for me. I prefer to get the pan off, CLEAN IT (ever see the inside of a transmission pan? Once you do you will want to do pan drops), clean the magnet (once you see it, you will want to clean it and do pan drops every time), change the filter and fill it back up. If you do them on schedule, it will be fine. I have never heard of systemic failures due to transmissions serviced on time with pan drops instead of flushes where that is an option. Now.....failures due to bad fluid, like early 4R70Ws and AOD-E with Mercon before they came out with MERCON V....YES, or early Chrysler Ultradrives before ATF+3 or 4, and serviced with DEXRON III....YES.
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