ATF analysis for '02 Acura RSX, 62000 miles

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Apr 19, 2004
New York
I drained and refilled my Accord at 25K and plan on doing it every 25K. I used Genuine Honda ATF which is kind of pricey (Approx $5 a qt) but it only takes < 3 qts. I think this OCI should give me long A/T life.
LT4Vette, my RSX has been the best-made, most reliable car I've ever owned--by far. It's a good thing too because I live 120 miles from the nearest dealer. Why do I do oil analysis and not simply change the fluid? Out of curiosity, mostly. Honda's 110,000mi OCI is unusual, and I'm interested in knowing if the ATF can really go that long. Also, why change the fluid if it's still good? Finally, the report adds to the BITOG database so others can help come to the conclusion of "what's normal" for this automatic transmission.
I think I would change this out at this point. Not an expert but iron of 111 and aluminum of 35 would be enough for me. These are the two wear metals seen most often on a Honda/Acura transmission from other analysis. Viscosity is just difference in labs. First was at 40 degree second was probably at 100 degrees. I think this shows that a complete change every 30,000/60,000 or a 1/2 change every 15,000/30,000 is the way to go with these transmissions. Thanks for posting this data to help us all. [Cheers!]
This is one reason why I suggest changing the factory fluids at 5-10,000 miles in order to flush manf. crud. In addition, the first 5,000 is most wear prone since the clearances are tight and heat builds up fast, oxidizing the fluid. And don't ever believe the factory fill lie. UOA's tell us what condition the fluid and tranny might be in. In your case, the fluid sheared; the aluminum is linear and not unusual since the cases are aluminum and Al sloughs and leaches out of the case. Looking at the numbers, the calcium add is working since your tan actually went down. It would have been more instructive if we knew the oxidation potential.
Is this the 5 speed? The TAN is lower than when new. The iron & copper look elevated. I agree with Mola, change that fluid out. The 110k mile interval or (60k mile if severe) is BS. How much does a simple drain & refill take - 3 qts? It's really simple to do even easier than changing the oil. There really isn't a reason not to change the fluid (that I can think of) except for curiosity of how long will it go w/o changing & what would the UOA look like then.
change the fluid more often Jay, I always did mine once per year. The reason is the thinning issue, ATF is super thin to start out with and as you know the gear action of trannies shears fluids fairly easily. The fluid may have some additive left but it will thin with age and ATF's have low levels of AW's.
This is the latest ATF analysis for my '02 Acura RSX at 62,000 miles. I'm showing the previous analysis at 29,500 miles for comparison. This is the original factory-fill ATF, and it has not been changed. Honda recommends 110,000 miles OCI for the ATF. AV Lube/PMI was the lab for the first sample, and WearCheck did this latest sample.
Miles 29.5K     62K

Fe     81       111
Cr      0         1
Pb      0         3
Cu     19        20
Sn      0         0
Al     17*       35*
Si      8        12
Na     13        12
K       5         0
B     300       310
Ba     --        26
Mo      0         0
Mg    235       261
Ca    302       407
P      11         2
Zn    400       392
S      --      1061

TAN   .91       .64
Kv@40 23.4cSt 13.8cSt


Both labs flagged Aluminum as slightly elevated. I'm pleased that the TAN is still very low, but could the viscosity really have thinned that much?
The viscosity difference is suspicious... But why not just simply change it instead of spending the money on UOA? I change the ATF in my 97 Integra LS every 15k since I got it at 60k mi, and it now has 120k mi and the transmission is still strong. In the last 3 changes I did them every 7500 mi so that to get more new fluid in. Now I will resume to every 15k until the car falls apart.
Curious how you take a sample. Drain and fill a snap, something I love about a Honda vs. dropping the pan on the old Astro. After 1k miles on my '05 Ody I did two drain/fills (3,5 qts out of 7.2 qts each time). Did another at first oil change at 4k miles. Ody OM calls for ATF change-out (4 times drain/fill) at 30k miles. I think Honda with their past tranny woes is no longer quite so brave.
Jay, Has there been any degradation in the shift quality, particularly after driving hard? That would be an early indication that the physical/chemical properties of the fluid have been significantly degraded. The fluid should have "sheared out" relatively quickly and should now be thickening due to evaporation of the lighter fractions and oxidation....So the vis numbers look screwy to me! Once the Fe concentration gets > 100 ppm, it can start to "bootstrap" the wear rates of softer materials and act as an oxidation catalyst. You'll see this 100 ppm iron level used as the condemnation limit for some commercial diesel engines, for this very reason.... Ted
About the viscosity--both figures are at 40 deg C, and the newest one looks suspect to me also. In my experience with motorcycle UOAs, the gears will quickly shear an oil in 1000 miles, and not much shearing occurs afterward. The transmission still shifts very smoothly. About the wear metals--most of the wear metals shown are break-in, obviously. Over the last 32,000 miles iron is only 30ppm--less than 1ppm/1000miles--which I think is pretty good for a transmission. The next highest is aluminum which is .5ppm/1000 miles. From a wear standpoint, the fluid looks OK. From a TAN standpoint, the fluid is OK. From a shifting standpoint, the fluid is OK. From a viscosity standpoint, it may have to go. I'm not sure. Draining the fluid only replaces 3qts out of 7qts.
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