Oil Analysis on myTransmission Factory Fill

[OrdnanceMarine]

I did a complete flush on my transmission at the end of June when I was installing my aux transmission cooler and saved a sample to have analyzed. Below are the results.

This was the factory fill and the hardest this transmission was run was towing my trailer on our maiden voyage where the fluid was a bit over 240 degrees on a slow steep climb to a campsite at about 5000'. This was the first trip I was able to read my transmission temp via my ScanGaugeII and I also was seeing high 230's during some moderately fast climbs in 4HI and lower 230's in 4LO on my way to an old mining town at over 8000' so I'm guessing my transmission had an average life for a 4X4 4Runner up until that point.

From now on when I buy a new vehicle with an automatic transmission I think I will either install a Magnefine filter right off the bat or perform a flush after 5-10k miles to get out all of the grit from the initial break-in that is visible in my analysis.

Now I am considering sampling at the end of each camping season to see how the fluid is holding up now that I do 1000-2000 miles per year of towing near the MGVR up some serious grades to get to camp sites in the Eastern Sierra Nevada.

Any thoughts?

 

[diverscale]

Thank you for the informative post, very good info here as our 4runners don't have an aux cooler and that might raise some worries.

I'll do my oil change at 60k miles for sure.

 

[CookieRoe]

Thanks for sharing!! This could be the first post of "fluid analysis" of the ATF in our trannies. Some numbers are high, but I don't know what they mean. Anyway, this could favor the "change the ATF" opinion. When Toyota originally put the "sealed transmission" on the market, the manual said NOT to change the fluid unless it experienced severe conditions. Toyota has since revised this to have it changed (correct me if I'm wrong) every 100,000miles.

Very interesting.

 

[OrdnanceMarine]

I'm kind of interested in what the transmission fluid looks like in some of the other 4Runners here. If a few other people here had samples analyzed (which can be done for under $25) at different odometer readings we could probably gain an understanding as to whether all of these wear metals (lead, tin, iron, copper being the main ones here) all show up early on and then stabilize (which would argue for a longer change interval) or if the extra metal results in increased wear (which would argue for an early change or something like a Magnefine filter). Either way since changing the ATF costs about 4 times what an oil change costs and *could* last up to 100,000 miles I think it is the perfect candidate for taking an occasional sample and building a database here to help us figure out how to get the most life our of our transmissions without over-maintaining our trucks.

While I don't think the payback will show up early on in ownership, I really think leaving the factory fill in for 100k miles could be a "silent killer" for those that plan on keeping our 4Runners for a long, long time.