Transmission oil question - Toyota Nation Forum : Toyota Car and Truck Forums

tekno9000 · 05-10-2010, 08:50 PM

I just changed my radiator and needed to top off my transmission oil. The manual mentions that we have to use Dexron II.

When I went to NAPA, the guy said it was discontinued.
Autozone did not have it. The person was all lost when I told him about Dexron II.

Finally went to Toyota Dealer who gave me a quart of transmission oil which mentioned it was a replacement for Dexron II as well as Dexron III.

What is the true story? Please advise.

Thanks.

***JohnGD*** · 05-10-2010, 09:06 PM

GM's Dexron II was a very old, superseded standard. The Dexron series ATF's performance was increased over the years and led to the familiar Dexron III-h and then Dexron VI.

You can still find plenty of replacements for D-II/III on the market, such as the excellent synthetic blend Castrol Import Multi-vehicle ATF (~$4.5/qt Walmart), or SuperTech Ford-licensed Mercon-V (suitable for D-III, ~$3.8/qt) or Valvoline MaxLife ATF (a high mileage ATF, for cars >75k miles). Or you can use Mobil-1 Fully Synthetic ATF or other boutique ATFs like Amsoil and Redline.

When GM introduced the newest Dexron VI standard, the licenses for older products were discontinued. Therefore oil companies can no longer sell "licensed" D-III. They have to call them "suitable for D-III", "formerly used D-III", etc. However, D-VI has some problems with older transmissions that don't like very thin ATF. GM issued a TSB for that. So I would NOT use D-VI in these applications unless you have the excellent Hydramatic 6T/6L series transmissions from GM. But I figured they only sold you an Aisin transmission.

Unless you don't want to spend more than ~$2.25/qt for dino D-II/III ATF (WalMart), I'd say spring the ~$3.8 for the SuperTech Mercon-V that's suitable for D-III. It has a tight specification and improved shear stability, plus the price is right. In fact, while at it pick up some Motorcraft Synthetic Blend 5/10W-30 for your next oil change. Good stuff. Or add another $75 or so and get the synthetic blend Castrol Import Multi-Vehicle ATF at ~$4.5.

Quote:

Originally Posted by tekno9000

I just changed my radiator and needed to top off my transmission oil. The manual mentions that we have to use Dexron II.

When I went to NAPA, the guy said it was discontinued.
Autozone did not have it. The person was all lost when I told him about Dexron II.

Finally went to Toyota Dealer who gave me a quart of transmission oil which mentioned it was a replacement for Dexron II as well as Dexron III.

What is the true story? Please advise.

Thanks.

***JohnGD*** · 05-10-2010, 10:24 PM

Make sure you change the differential too, uses the same ATF.

make sure the fill plug can be removed before you loosen the drain plug! For obvious reasons.

schumionbike · 05-10-2010, 11:17 PM

when you're topping off, it it safe to mix different ones? Like dino Dexron III and the synthethic blend one? Thanks.

***JohnGD*** · 05-10-2010, 11:47 PM

I personally don't have a definitive answer for that, because for ATF by definition I always mixed (less than a complete flush). Even a complete flush typically gets out about 95% only. No problems that I know of. And there is very little Q&A about this on ATFs (plenty on motor oils, see below).

I do seem to recall that even in a synthetic oil system, such as VW/Audi, you can use 1 quart of out-of-spec oil in an emergency. Maybe that's 1 quart of dino. Don't remember for sure. Also in Honda Z-1 ATF system you can use 1 quart of Dexron III.

There are hydraulic systems that do not permit mineral/synthetic mixing. That's the case of power steering/hydraulic systems requiring Pentosin CHF11S and CHF 7.1. But it said so on the label. Across the pond they like to make things difficult. Like picking socket sizes they know you don't normally have.

See what companies like Valvoline and Mobil say. But these are for engine oils. The only fluid by law have to be compatible with each other that I know of is DOT certified brake fluid of the same rating, per FMVSS-116, S6.10.

http://www.valvoline.com/car-care/motor-oil-myths/

http://www.mobiloil.com/USA-English/..._FAQs.aspx#top

Quote:

Originally Posted by schumionbike

when you're topping off, it it safe to mix different ones? Like dino Dexron III and the synthethic blend one? Thanks.

***ASG14*** · 05-10-2010, 11:54 PM

I have a mix of Dexron 3, Toyota ATF-IV, and Royal Purple in my Tranny, lol.

All are fin, and yes you can mix. Dextron 2/3 Toyota's can use ATF-IV, but NOT the other way around. It;s forward compatible.

***JohnGD*** · 05-10-2010, 11:56 PM

So while I can't link you to an official answer from an oil company, in short I'd say yes. And I do.

You can check out SuperTech Ford licensed Mercon-V (lic# M5081001) that's also suitable for D-II/III applications. It's a friction modified ATF of excellent shear stability at the right price. Ford tightened the specification so when you buy any brand of Mercon-V (that's also suitable for your DII/III, not all are as some are old Mercon-V spec) you can rest assured about what you're getting.

Next step up (cost-wise) is Castrol Import vehicles ATF, an excellent synthetic blend. Like ST Mercon-V I'd use this in the A140 series differential, if you still want to use dino in the transmission side to save cost.

Quote:

Originally Posted by schumionbike

when you're topping off, it it safe to mix different ones? Like dino Dexron III and the synthethic blend one? Thanks.

schumionbike · 05-11-2010, 09:46 PM

Thanks John. I actually got the Mercon IV ATF recently. Just got to find time to do my oil change and fill and drain my ATF one of these day. Thanks again.

***JohnGD*** · 05-11-2010, 10:08 PM

You're welcome!

That's Mercon-V right? There is no Mercon IV. Just wanting to make sure.
Did you get the Walmart SuperTech Mercon-V that's suitable for D-III?

Otherwise you have to read the label and make sure the formulation is suitable for D-III. Because older Mercon-V spec isn't. Ford phased out the old "Dexron/Mercon" and use the new formulation of "Mercon-V" in place of it. Again the friction modified M-V is vastly superior to the old Dex/Merc.

Quote:

Originally Posted by schumionbike

Thanks John. I actually got the Mercon IV ATF recently. Just got to find time to do my oil change and fill and drain my ATF one of these day. Thanks again.

schumionbike · 05-11-2010, 10:22 PM

Quote:

Originally Posted by JohnGD

You're welcome!

That's Mercon-V right? There is no Mercon IV. Just wanting to make sure.
Did you get the Walmart SuperTech Mercon-V that's suitable for D-III?

Otherwise you have to read the label and make sure the formulation is suitable for D-III. Because older Mercon-V spec isn't. Ford phased out the old "Dexron/Mercon" and use the new formulation of "Mercon-V" in place of it. Again the friction modified M-V is vastly superior to the old Dex/Merc.

You know what, I just look at the label closely and it just say Supertech Automatic Transmission Fluid (suitable for vehicle previously serviced Dexron III/ Mercon Brand. Guess I picked up the wrong bottle. Dang, forgot where I put that receipt.

***JohnGD*** · 05-11-2010, 11:29 PM

That actually will work. No worries.

If you paid something like $2.77 then it's a dino version. Not bad either. However, if you paid something like $3.77 then it's a synthetic blend multi-vehicle or the Ford licensed Mercon-V. If the syn-blend multi-vehicle then it should also be suitable for "Mercon-V" (in addition to Dexron/Mercon).

Given the $1 difference you can see why I like to suggest the more shear stable $3.77 version. The gallon bottle of dino is even cheaper (~$2.5/qt), however, if you need to do a flush or the sort. Sounds from the Dex/Merc and no Merc-V description it's the $2.77 version?

But even the dino is fine. I'd just use it this time and leave the SuperTech Mercon-V for next time. In fact, if you haven't tried the Motorcraft 5W- or 10W-30 synthetic blend motor oil for $2.77/qt you should try that as well. I'd use the thickest oil approved for the temp range you operate in.

Quote:

Originally Posted by schumionbike

You know what, I just look at the label closely and it just say Supertech Automatic Transmission Fluid (suitable for vehicle previously serviced Dexron III/ Mercon Brand. Guess I picked up the wrong bottle. Dang, forgot where I put that receipt.

schumionbike · 05-12-2010, 06:28 AM

Cool, Yeah, it only cost like 11 buck for the gallon. I guess I'll just use it anyway, I got to drain my transmission soon anyway. Currently I'm using Castrol GTX high mileage oil, good stuff, a bit more expensive then every else though. Not a very scientific test but that oil doesn't get dark as quickly as some of the other stuff that I've tried like Mobil 5000. The Mobil 5000 is a very reasonable priced motor oil though. I'm a bit wary as to using sythethic/blend oil though since my car is leaking some oil from the valve cover gasket area, I lose like 1 quart every 3 K.

peshwa · 05-12-2010, 10:32 AM

I used Valvoline Maxlife ATF and its been great so far. I noticed a big difference when I replaced my differential fluid with Valvoline Maxlife ATF. The car is noticeably better in acceleration and coasting too. I guess it was changed for the first time ever for this car..lol...but make sure you change differential fluid too along with transmission oil.

LittleWhiteBubble · 05-12-2010, 10:59 AM

^ x2 on the valvoline. I haven't done my diff. though.

I just looked it up. It sounds like the V6 camry's share fluid between the diff and trans, so they don't have to do the diff change. But the 4 cylinders don't. I guess I know what I'm doing tomorrow.

There's a thread in the DIY section on how to do it.

djb2 · 05-12-2010, 09:27 PM

I believe the V6 automatic transmission has separate drain plugs for the differential and transmission, but that the partition between them has an opening so that the ATF spills over to fill up the diff section.