Long term results for 2001 V70 auto transmission drain and fill

[Oro]

interesting observations about the viscosity differences between fluids. i used maxlife in my 850 transmission once and noticed some hesitation afterwards - maybe the lower viscosity was the culprit? switched back to oem fluid and it seemed happier.

I’ve put MaxLife in an Aisin U151E transmission (Lexus) and experienced the same. That unit uses T-IV, which is more similar and same viscosity as the Dex-II and Dex-IIIF the 850 used when new.

I still like and use MaxLife, but only in vehicles designed for low viscosity fluids like Dex-VI or Toyota WS (3324, like newer Volvos). I especially like it instead of WS as it has been a problematic fluid with premature failure when it first came out.

[Oro]

…
And can you maybe shed light on why a big drain and fill transforms shifts but only for a few miles. It isn't just adaptations I think. Last year after a huge drain and fill, for a brief moment I had the fastest, smoothest shifts that last just a few miles, after which they go back to how they were.
I mean even with sticking solenoids, how did new fluid affect the transmission in a positive way seemingly curing it.

Only in a limited way - probably not fully. Personally, I’ve never experienced that except in engines, where I definitely have.

Two ideas I can offer is that 1) if it was a LONG time between fluid changes, and the old fluid was fully loaded with contaminants, I could see that happening. By “loaded” I mean the fluid’s detergents were expended in carrying the maximum amount of particles, and the fluids base oil diluted. The new fluid comes in, works as it should, but then starts loading up also and degrading. Like having a sink full of dirty dishes and water, and you drop in a tiny bit of soap. It bubbles up and looks ok, but come back in 1/2 hour and it’s all slimy and greasy.

That’s one scenario that could happen. But if you have a relatively clean fluid, and replace some or all of it with fresh, that should not happen unless there was enough of a viscosity change the computer noticed it. Which brings up 2) - if you up the viscosity but use the same programmed shift pattern, it can firm shifts. Then the ECU sees a change and works to counteract it and return to it’s long-term pattern. That’s why it is often crucial to blank the ecu when a problem like that is suspected. Disconnecting the battery is often not enough to do that; there is non-volatile memory.

I’m not an absolute expert at this, but these are scenarios I’ve seen/heard of, or could imagine.

[volvolugnut]

In my understanding, fresh ATF of any type will have better detergent action to clean solenoid deposits. By this thinking, if you keep draining and adding new ATF after 50 to 100 miles of driving, you will renew the detergent action and accomplish more cleaning.
However, if there is enough junk in the fluid to clog the filter, you are done unless you can clean the filter.
volvolugnut

[chrism]

Interesting conversation about ATF replacement, however I’m a bit surprised at how many people are using a drain and fill process to accomplish the replacement. On the P2 cars it’s rather easy (after one initial sump drain and refill) to break into the return trans cooler line and let the internal pump push the dirty fluid out while new fluid is added via the dip stick port. This method provides a 100% fluid replacement using approximately 10-11 quarts of fluid.

[volvolugnut]

As i mentioned in previous posts, I think there is a benefit to doing a drain and refill with a driving period before repeating the process. But either way gets clean fluid in the transmission.
volvolugnut

[volvolugnut]

Now (November 2024) the V70 has 214K miles or about 6K miles since the start of repeated drain and refills. No more transmission codes or harsh shifts.
Now I just need to fix the fuel tank vent issues causing frequent codes.
volvolugnut

[vtl]

Doesn’t the Volvo fluid have additional friction modifiers for its software in the Aisin making it effectively less slippery? That was shared elsewhere on the forum where LubeGuard HFM would improve standard 3309 fluid.

I think it was me. I experimented with ATF fluids for about 10 years and $1000, nothing compares to Volvo ATF. Also about 3 years ago I rebuilt my transmission, the initial fill was with T-IV, but the frictions were soaked in Volvo ATF. It was shifting butter-smooth for about 3 days then the shifts started to deteriorate. My understanding is it wore the modifiers out from upper layers of the frictions. I did drain&fill with Volvo ATF and it was better since then.

Not sure what Antherzoll's test proves. My butt senses differences between T-IV and 1161640. The test replicated in 4 AW55 transmissions I had/have: 11616140 is best. I tried T-IV, apparently, because everyone said it's the same stuff like Volvo puts in its jugs, but my transmissions simply shifted worse with T-IV.

Extra $20 for 1161640 over T-IV every other year does not rob me.

[dikidera]

I will also attempt with volvo fluid. I filled two liters, no difference yet, but it's a huge amalgamation of Mannol, Lubeguard Platinum and Ravenol. So it will take a while to clear it out with more Volvo fluid.

[vtl]

I will also attempt with volvo fluid. I filled two liters, no difference yet, but it's a huge amalgamation of Mannol, Lubeguard Platinum and Ravenol. So it will take a while to clear it out with more Volvo fluid.

Ravenol I switched Toyota WS in my Tundra to Ravenol. A lot of city driving for me, Toyota ATF wears out quicker than I would like it to and the truck starts to jerk. ATF replacement is a hassle on my Tundra, which includes removal of heavy steel skid plates and operating bare hand in the vicinity of hot exhaust. So decided to give a try to Ravenol. Ravenol MTF-3 did previously a pure magic for the transfer case, which was nearly impossible to switch out of 4LO in deep freezing temps. Both differentials also run on Ravenol.

[volvolugnut]

In the last month I started getting some hard shifts and at least one Transmission Service Required warning. I did another pan drain and refill with about 3 quarts of Mobil 3309. Current miles are about 217,900. It has been about 200 miles since the latest drain and fill with better shifting and no warnings.
I plan to do another drain and fill in another 100 miles.
volvolugnut