2003 Civic M/T 5763 mi

[himemsys]

This is the first sample after getting the input shaft and clutch release bearings replaced. I probably should've done it sooner to flush the silicon sealers out, but this was the soonest I was able to get to it. Yeah, 100ppm Si seems super high, but I think it's probably normal for first fluid after having the tranny opened up. Everything else seems fairly normal. I'd like the iron to be lower, but 4.51ppm per 1000 miles doesn't seem too out of line.

What does seem out of line is the TAN. This is genuine Honda MTF and I've had a VOA done in the past by Blackstone. Virgin TAN was 3.1, so this TAN result seems very low. The rest of the additive package looks the same as my VOA, so I wonder if it's lab error/different testing methods of TAN or just a minor formulation change in the MTF?

I wish I knew the virgin oxidation value of Honda MTF fluid.

Here's some more detail on my transmission's oil analysis history:

 

[2010Civic]

I bet a lot of people don't send in oil samples for a 20 year old Civic.

 

[himemsys]

I bet a lot of people don't send in oil samples for a 20 year old Civic.

I bet you’re right. I’m an outlier.

 

[Popsy]

That Honda MTF has an add pack reminiscent of a stout engine oil!
Did you try other oils in the past in that transmission (but then why would you, according to the results)?

 

[himemsys]

That Honda MTF has an add pack reminiscent of a stout engine oil!
Did you try other oils in the past in that transmission (but then why would you, according to the results)?

I've never tried any other MTF besides genuine Honda. And it looks like its formula has not changed much over the years.

I did ask OA to retest the TAN because the virgin TAN should be 3.1 and that number should climb with use. So a result of 1.85 doesn't make any sense.

 

[fantastic]

The iron seems to be close to the previous sample x/1k so I'd say it's fine. The silicon is the issue here w/the work done. Good for you to flush it out. The TAN I'd ask what method each lab uses & go from there. Interesting to see these.

 

[Ausfahrt]

Interesting.
Our family had the same car that went through three teenagers learning to drive stick shift and it had over 250,000 miles on the original clutch (and gear oil) when we finally sold it. That was one of the most reliable cars that I have ever owned.

 

[kschachn]

The iron seems to be close to the previous sample x/1k so I'd say it's fine. The silicon is the issue here w/the work done. Good for you to flush it out. The TAN I'd ask what method each lab uses & go from there. Interesting to see these.

The silicon showing up from sealants is a complete non-issue. It's not silicon dioxide.

 

[himemsys]

The silicon showing up from sealants is a complete non-issue. It's not silicon dioxide.

Good to know. So there is no urgency to continue doing short runs to flush it all out. I will probably go another year before flushing it again.

edit: not that it's a pain to change the MTF. It's actually easier than changing the engine oil (and that is an easy job too on this car). The main issue is Honda MTF is so expensive. 2qts of this stuff is more expensive than 5qts of quality engine oil.

 

[kschachn]

Good to know. So there is no urgency to continue doing short runs to flush it all out. I will probably go another year before flushing it again.

Yeah it’s not a whole lot different than the silicone anti-foaming agents already present in the gear oil.

 

[himemsys]

I had Oil Analyzers rerun the TAN test, but it came back at a similar 1.91. That leads me to believe there was a minor formulation change in this fluid?? Virgin TAN is 3.1 (I got a VOA at the beginning of 2022), and TAN climbs with use, so a result less than 2 is pretty weird. Anyone else have any thoughts? Is there more than one type of TAN test? Could Blackstone and Oil Analyzers be testing TAN in different ways?

Here is the VOA:

Genuine Honda MTF VOA with TAN