I plan to flush my ATF in October when the temperature cools off a bit and wondered if anyone can recommend a quality brand of regular Dexron 3?
My old mechanic told me recently that there isn't much difference between synthetic and dino.

Let me add to the chorus:

Changing your ATF is excellent.

Your old mechanic is perfectly correct if he is basing his opinion on the color of the fresh fluid. The synthetic is very hard to tell from the non-synthetic.

Now, if he is basing his opinion on the flash point, or the pour point, or the resistance to oxidation, or the service life, or the cost per mile--he is all wrong.

Change all the fluid, using the readily available instructions. If you use an excellent synthetic ATF, such as AMSOIL (biased--been using and selling the products for 25 years) or Mobil 1, you will probably not have to repeat the excercise for as long as you own the Volvo, or maybe 45-50,000 miles anyhow.

If you use non-synthetic, change it no less than every 2 years.

I'm a long way from being an expert, but it seems to me that the primary reason for regular fluid changes is to get rid of the dirty stuff that's comtaminating the innards of the transmission. I can see where the synthetic stuff might oxydize less and give smoother shifts, but, I can't grasp why it would resist contamination any better than dino juice. Seeing that synthetic fluid costs three to five times more than dino, wouldn't changing it more often with dino fluid be a better plan than changing less frequently with synthetic fluid?

The synthetic fluid doesn't oxidize like the non-synthetic does (and that's where most of the color comes from. The film strength is hundreds of times stronger than the non-synthetic, which about eliminates metal to metal contact, and greatly reduces wear. Oil analysis will show (and has shown) that an extended use of synthetic ATF will result in less wear than multiple changes of non-synthetic.

I won't try to sell you on any brand.

But the statement about not much difference between synthetic and petroleum ATF is pure BS hogwash. There is a HUGE difference. I can have you come over and meet my trailer pulling neighbor. Petroleum ATF wouldn't survive one season in his rig. He's 3 years now on synthetic ATF, and it still looks and analyzed as fine. The specs bear this out as well.
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http://www.fidalgo.net/~brook4/oilslubesfilters.html

I would do the Syn on the tranny. I did a flush with dino for 5K miles, then did another with Mobile...... My what a pleasant difference. SO smooth..

If your going to flush the AT, I would go with a synthetic. There is overwhelming evidence that it is better for the trans, and will outlast any dino atf. Now you need to understand that I am kinda hard on AT's.....I do 90% of my driving in and around NYC....read a lot of stop & go.........
I had the AT on my 2000 S70/GLT flushed at 15K mi. and it was dark as hell and had a burnt smell(I was getting a shutter going into and out of lock up at speed also). I filled the trans up with Mobil 1 ATF, and its been about 12Kmi. now, and its still bright red, and the shutter has been gone since day one after the flush.
Also Volvo has a TSB out that says to flush with synthetic(Volvo branded), if there is just about any shifting problem with any of the 99> models.

BTW: the drain and fill system....while better that nothing....it aint much better. The AW tranny in the Volvos hold about 15 quarts, and a drain from the plug only gets out 2 qts or so....you do the math.

in any case a flush with something is better than not flushing at all.....I think????

Steve F.
Hoboken, NJ

My vote would be to use synthetic like Mobil 1 ATF. For one thing they last about 2-3 time longer so therefore you wouldn't have to do this again for another 100k miles or so. Yes, it does cost a bit more initially but in the long run its a wash. I think I paid about $4.75 a quart at Kragens.

There are a few of us around here that are sold on synthetics for both the motor and tranny. But I just run dino in my engine and synthetic in my tranny.

Also, look into Bay 13 tranny flushing information. Their procedure is real easy to do. Highly recommended...

I used to use Esso ATF when I was a member at Sam's Club. They sold it for around $10 a case. I flushed my tranny 3 times in 3 years, and would drain & refill the pan at each oil change (5k miles)

In my '96, I used Kendall, which cost me $18 a case. Is it any better than the cheap Esso? I don't know. The point is that I drain the pan regularly. I don't see the need to run an expensive synthetic.
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RussB in Ct. - '96 855T- '91 940T - '93 850GLT (R.I.P. 6-16-02)

Russ;
I'm in agreement with you. Can you tell me a bit more about what is involved when you say you "drain & refill the pan"? Do I have to remove the pan itself or is there a drain plug? How much fluid is held in the pan?

Thanks!
Fred S.

There is a drain plug, similar to the motor oil drain plug, except a 24mm socket/wrench is used to remove it. It is located perpendicular to the motor oil plug, on the driver's side. It uses the same aluminum crush washer as the motor oil drain plug. The pan holds about 3 quarts.
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RussB in Ct. - '96 855T- '91 940T - '93 850GLT (R.I.P. 6-16-02)

how do you recommend getting the rest of the old ATF out? I was thinking about using one of those little pumps that the junk shops sell with a hose down the dipstick tub but then I realizeed that thiat would be no better than the drain plug. Do I have to splice a drain line onto the cooling line do do it right or is there a kit available.

Hi Russ,

CAn you tell me the exact location of the pan please? Is it just behind the engine oil pan or in front of the engine oil pan under the splash guard. Thanks.
Ihsan

Russ;
Thanks for the descriptive answer. But do you mean to say that the three quarts
in the pan never actually get flushed out if you use the BAY 13 method?
Is that why you drain the pan? Sorry by I am a neophyte when it comes to working on my car. I try to learn somehting new each day.