Mobil ATF JWS 3309

KEWROCK · Post by **KEWROCK** » 07 Dec 2009, 08:56

I was under the impression that you can't blend Mobil1 synthetic with fossil based ATF, especially Dex/Merc. The only other sythetic ATF I've seen that specifically said it was blendable with fossil Dex/Merc was Amsoil, But I wouldn't trust anything sold through a pyramid marketing scheme.

Every artical I've read on this site says you have to get every drop of fossil Dex/merc out of your system before adding mobil1 or Volvo branded JWS3309.(which doesn't make sense because mobil1 MOTOR oil was always fully compatible with fossil.)

Besides, in my region I have never seen mobil1 ATF on the shelves of any store. I've got Pep Boys, Autozone, Advanced, RS/Strause and a few mom&pops not worth mentioning. Walmart here only carries an off brand ATF(Pro something-or-other in a blue bottle). Mobile1 MOTOR oil is found everywhere though.

Post by **FlyingVolvo** » 07 Dec 2009, 09:05

My 2000 V70XC doesn't require 3309, but I had no problems going from the slightly overdue dino fluid to Mobil 1 Synthetic ATF. I just did 4 drain and fills with no problems at all.

I think it's only the 01 and after cars that require 3309. Plus, I'd rather have a good synthetic one than even a good dino one. Transmission heat worries me a lot as I often go through 100+ degree heat. I'd rather have a fluid that is a little more resistant to thermal breakdown.

850 Turbo1 · Post by **850 Turbo1** » 07 Dec 2009, 09:08

In terms of blending I don't know...But I believe if you drain and fill...drive 100 miles...drain and fill drive another 100 miles ...do this about 4 times...I believe you'll have expelled most of the bad stuff...I would think that using Mobil 3309 ....would be ok even if you have another type of oil in there...

I have just regular "ATF" in my car...some cheap stuff ....I've had it in the transmission for the last 6 months until I finally figured out that I should not have done that. I don't have any symptoms at all...but I'm about to drain and refill about 4 times unless I'm advised otherwise....

I'm in Canada where things are not as readily available as the USA...and I found Mobil 3309 everywhere I went...Maybe you could ask for those parts stores to order it...because I know they do order upon request.

So now...haha...I have the same question pretty much....is it safe to drain and refill with Mobil 3309 if previously I had just regular ATF??

850 Turbo1 · Post by **850 Turbo1** » 07 Dec 2009, 09:10

ecbsykes wrote:My 2000 V70XC doesn't require 3309, but I had no problems going from the slightly overdue dino fluid to Mobil 1 Synthetic ATF. I just did 4 drain and fills with no problems at all.

I think it's only the 01 and after cars that require 3309. Plus, I'd rather have a good synthetic one than even a good dino one. Transmission heat worries me a lot as I often go through 100+ degree heat. I'd rather have a fluid that is a little more resistant to thermal breakdown.

As far as I can gather from this forum 3309 is required in all 850/s70 models...though I believe I've been lucky with regular ATF for the past 6 months

plainv70 · Post by **plainv70** » 07 Dec 2009, 09:41

As far as I can gather from this forum 3309 is required in all 850/s70 models...though I believe I've been lucky with

No. JWS 3309 ATF is only required for post MY99 (2000 in the US) automatics, variants of the Aisin-Warner 55/50 transmission.

3309 is, however, backwards compatible with most ATFs, e.g. Mercon III, so it can be used with the pre-'99 cars, however, since it is much more expensive than the OE ATF, no one typically chooses to do so.

850 Turbo1 · Post by **850 Turbo1** » 12 Dec 2009, 19:36

I stand happily corrected

Mobil ATF JWS 3309

Re: Mobil ATF JWS 3309