1999 and 2000 V70 XC trans flush/ ATF

ddmd · Post by **ddmd** » 05 Jan 2016, 19:19

Pretty new to this forum. I have a 2000 V70XC with 180,000 miles. The ATF has been flushed at a Volvo dealer at 35, 70, 110, and 145K
with Dexron III, is still clean and pink, and shifts smoothly. I also just purchased a 1999 V70XC with 57,000 miles privately, with a history of a
transmission flush at 30,000 miles with an unknown ATF(there is no paperwork but a sticker from a Volvo dealer in the engine compartment
"documents" an ATF flush at 30K and it's also recorded on the CARFAX). It shifts smoothly and is reddish-brown and smells OK.
I thought I would would perform an ATF flush on both so I've read a lot of forum info on the transmission flush and ATF type for the AW 50-42 4-spd transmission.
(same trans in both cars as per the owner's manual).

As I understand it(and please correct me if I'm wrong):
1. Dexron III is called for in the owner’s manual for the AW 50-42.
2. A Volvo service bulletin calls for the use of JWS 3309 Spec ATF for "hard lockup engagement/disengagement in the AW 50-42 transmissions".
Doing a search for that service bulletin (http://workshop-manuals.com/volvo/s70/l ... ngagement/) also references using Dexron IIIG Spec ATF. Are JWS 3309 and Dexron III G the same thing?
3. I've read that Dexron III and JWS 3309 should not be mixed, so a complete flush (16 qts) would be needed to change from Dexron III to JWS 3309 or Dexron III G.

My questions:
1. On the 2000 XC, since I haven’t had transmission lockup issues, should I just continue using
Dexron III since it’s been used with all of the previous flushes?
2. On the 1999, I’ll have to do a full flush since the previous fluid used is unknown. Again, Dex III or JWS 3309?

The advice from 3 Volvo dealers with these questions (sheesh):
Dealer 1. We only use Dex III (not aware of the bulletin)
Dealer 2. We only use Dex III (hadn’t heard of the JWS3309 spec)
Dealer 3. We perform a full flush with 3309 on all of these transmissions,
whether or not the harsh lockup exists.

Sorry for the long winded post. Thanks in advance for your thoughts/advice.

Post by **abscate** » 06 Jan 2016, 03:30

I'll let the experts chime in on this transmission as the 2000 in particular you want to be careful about the right oil and mixing.

With this history, and good function, don't be in a hurry to flush them. Certainly wait for good weather.

Post by **JRL** » 06 Jan 2016, 06:23

If they're shifting fine, continue with DEX3.
Many use Mobil Synthetic tranny fluid, also fine but the DEX3 is just fine so why waste your money!
Steve, the 2000 XC is the same as a 1999 XC, only NON Turbos and Rs use 3309 as they have a 5 speed.

ddmd · Post by **ddmd** » 06 Jan 2016, 07:38

Yes, they are both the same 4 spd transmission
AW 50-42

James_A_Sousa · Post by **James_A_Sousa** » 06 Jan 2016, 14:30

At a couple of other boards there has been discussions about the down sides of flushes. Some are advocating - slow flushing - draining the pan and topping up the fluid like maintenance for 740s.

You pick the intervals.

ddmd · Post by **ddmd** » 06 Jan 2016, 19:47

It's interesting that my 2000 XC has had a full flush with Dexron III all 4 times at my Volvo dealer (dealer #3), the last one
being in 2012 at 145K. They are now advocating a full flush with JWS 3309 in all of these AW 50-42 transmissions, even
high mileage ones like mine. Their philosophy changed since 2012 and I don't know the reason. I've only talked to the Service
guy, as opposed to one of the techs, so I feel like I still don't have all of the info. I'm going to stop in and talk to a couple of the techs
to find out more.
As far as my 1999 XC with 57K, since I don't know which ATF was used at the 30K Trans flush, I'm probably committed to a full flush since the two
formulations can't be mixed.

Does anyone know if the Dexron III G is the same as RWS 3309? It seems to be since they are both mentioned in Service Bulletin
SB 43-0029 in different places.

ddmd · Post by **ddmd** » 11 Jan 2016, 16:37

FYI: I went to the Dealership and talked to one of the technicians who has been there for many years. Apparently, the Service Adviser
that I talked to was mistaken. While they will use the JWS 3309 in the AW 50-42 transmissions that experience the hard lockup engagement/disengagement issues, they generally still use the Dex III in these transmissions. The JWS 3309 ATF can certainly be
used (and some of their customers insist on it), but the Dex III is less expensive and works fine. He did recommend a full flush in
the '99 with the unknown ATF flush at 30K since you do have to be careful not to mix the two formulations. So Dex III it is for both cars.