04 s80 - specialist says don't touch ATF, but why?

[volvobro]

Thanks for your detailed response.
I drain & filled my ATF last week and the car has been driving great.
In comparing old fluid with new, it was extremely dark. I think it was definitely overdue.
I will be performing these drain & fills every 30k as suggested.

[oldironsights]

Very good, but you still need to drop the pan, clean the pan & replace the filter.
Drive ability will improve even more.

[volvobro]

I'm not entirely sure if my car has a transmission filter as I have been unable to find any information related to it.

[Elliot9874]

What was the result ?

[BobbyS1]

Just changed mine it was minging!
Can someone tell me where the ATF filter is?
I have 1999/2000 V70 estate right-hand drive tried to order filter but shops in UK don't seem to stock them is it a dealer trip?
Regards
Bobby S A Yank in England

[June]

Just changed mine it was minging!
Can someone tell me where the ATF filter is?
I have 1999/2000 V70 estate right-hand drive tried to order filter but shops in UK don't seem to stock them is it a dealer trip?
Regards
Bobby S A Yank in England

Only the 2.9/T6 equipped with the Hydramatic 4T65 E has a filter. Your 5 cylinder Aisin transmission has a screen in place of a filter. June

[rb61]

At one time (many decades ago) I heard a theory that a high milage transmission could start to slip if the old fluid with metal/grit was replaced. Some people felt that the debris was what created necessary grip between clutches. Your mechanic may be a believer.

[abscate]

The new found wisdom on these is the following; of changing your fluid kills your transmission, it was on the near death list anyway,

There is no question that regular renewal of ATF prolongs life of the transmission.

[CorpsOfficer]

For those who are curious, I completely changed my transmission (an Aisin 55-50SN) oil for the first time at ~135,000 miles and sent out the oil to a laboratory for analysis. This was the report from the tests:

Blackstone ATF report

ATF report.jpg (222.11 KiB) Viewed 1263 times

I do not yet have a comparable analysis for a clean oil or lightly used oil sample but this was more than enough to convince me to change the oil more frequently. I'm at 20k miles on flushed oil (I pumped all the oil out using the radiator drain when I sampled for this report) and it still looks red, smells new, but is beginning to mark a paper towel lightly brown. 30k miles is a good interval for a transmission of unknown history. If the oil was changed at regular intervals since factory, 50k-60k miles seems adequate to me. Volvo I believe recommends a 52,500 mile interval for "towing" applications in the maintenance schedule. Do whatever you are comfortable with, but I would not listen to those who tell you to never change the fluid.

[MoVolvos]

For those who are curious, I completely changed my transmission (an Aisin 55-50SN) oil for the first time at ~135,000 miles and sent out the oil to a laboratory for analysis. This was the report from the tests:

ATF report.jpg

I do not yet have a comparable analysis for a clean oil or lightly used oil sample but this was more than enough to convince me to change the oil more frequently. I'm at 20k miles on flushed oil (I pumped all the oil out using the radiator drain when I sampled for this report) and it still looks red, smells new, but is beginning to mark a paper towel lightly brown. 30k miles is a good interval for a transmission of unknown history. If the oil was changed at regular intervals since factory, 50k-60k miles seems adequate to me. Volvo I believe recommends a 52,500 mile interval for "towing" applications in the maintenance schedule. Do whatever you are comfortable with, but I would not listen to those who tell you to never change the fluid.

I purchased a 98 S70 T5 with 230ish K in 2012. The transmission fluid was coffee with a tint of silver. I used the same method and flushed it and drove it for a year. Flushed the following year as it started to get dark again. Car did not have problems but felt slower. Glide again after the second flush. I've only drain and filled once or twice out of caution for Honda's but last year I flushed, bypass the radiator and installed a transmission cooler on a 220K 03 Odyssey and have not had a problem. Had the van since 154K and it's the smoothest thus far with the cooler trans_fluid.

Seeing your report I think I will stick to flushes rather than putting clean fluid into dirty. Diluting to eventually to have cleaner fluid I suppose gives some a peace of mind but I haven't experienced or know of a case where a flush did a transmission in.