Looks to be I'm hogging the board this morning! Well... aren't I entitled to two questions a day?? LOL

I did a search on synthetic ATF and related problems... I didn't find anything that would indicate the automatic transmission (AW 72L) would slip after changing to synthetic. A Volvo mechanic told me that changing over to Mobil 1 synthetic ATF on my 1992 940 with 150,000 miles on her could lead to a slipping transmission. He advised against it.

My experience with other vehicles and my judgement tells me to go for it. I'm planning on doing the total flush from the radiator and switching over to Mobil 1 in the next week or two (finances allowing!!). What think you? Has anyone heard of or experienced any automatic transmission problems after switching to sythetic ATF? My search on the subject has only turned up "good news" regarding synthetic ATF.

Thanks! (for the second time today)

Steve

I found doing the tranny flush noticeably improved the driving performance... smoother and stronger.

It's also darned easy to do! Not any harder than changing the oil really. I helps having a helper to turn the engine on and off.

Good luck!

Your mechanic is running on very old myths. I've switched some eight cars (five Volvo 740/940 and three GMs) to Mobil 1 ATF with ZERO problems. And I've dropped pans 100k miles later to find amazingly insignificant evidence of wear.

When M-1 first came out in the 70s, it contained lots of esters which had the effect of radically cleaning the engine. In some cases, this led to leaking seals since seal quality then was none too good. As a result, everyone thought "synthetic=leaks". They long ago fixed this problem and now use all-PAOs. The M-1 ATF never suffered from this.

Thanks guys, for the feedback and confirming my thoughts on the subject. I'll feel more comfortable doing the switch now!

Steve

I have a 93 945 non-turbo and a 91 945 turbo. I bought the 93 with 107K miles and the 91 with 89K miles. I switched over to synthetic oil and transmissoin fluid (M1 then later Amsoil) a couple of months after purchase and that was 5 years ago. Both cars run great and have 50K more miles each on them. Oil consumption did not change between regular oil versus synthetic oil.
I would not use anything but synthetic and if M1 is readliy available, I think it is a great product. My local carparts place also sells Amsoil so I buy that. Both good products.