rdweninger Posted July 16, 2012 Share Posted July 16, 2012 Hello all, I want to drain and replace the ATF in my '85 GL Wagon FWD, 3AT. All the info I see is to replace/refill with Dextron II. I don't think they make that any more. What should I put in that 'ole 3AT for maximum life... Ha. Is it possible to drain it all out? I have alot of Mercron ATF... would that be compatible? Thanks for your help... this is my first AT... the rest are 5MT's. Quote Link to comment Share on other sites More sharing options...
somick Posted July 17, 2012 Share Posted July 17, 2012 I would not use Mercon. Use Dexron. Good luck, Sam Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted July 17, 2012 Share Posted July 17, 2012 Usually on the bottles it will say something like 'for applications formerly calling for Dexron II/III/IIIe, something like that. I would avoid any of the latest specs such as Dexron VI. These are thinner than older Dexron's and much more heavily friction modified. Quote Link to comment Share on other sites More sharing options...
skishop69 Posted July 17, 2012 Share Posted July 17, 2012 DO NOT USE MERCON!!!! It is Ford only unless otherwise stated on the side of the bottle. If it's straight 'original' mercon, things will happen to your tranny that are no bueno. There is nothing wrong at all with Dex6. It is backwards compatible with all Dex systems and far better than anything else out there. (I happen to work for GM, so I know a bit about it. lol) If you are having tranny issues, replace one quart of Dex with TransX. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted July 17, 2012 Share Posted July 17, 2012 Yes they claim Dexron VI is backwards compatible -- it may work just fine however it does not necessarily mean it is the best choice for the application. That is more to put retailers and service shops at ease that it's not yet another fluid they need to stock. Quote Link to comment Share on other sites More sharing options...
rdweninger Posted July 17, 2012 Author Share Posted July 17, 2012 Thanks to all for the input. I think O'Riellys has the Dex III or IV. The book says it holds 7 qts... but only 3 qts will drain out. I'll measure the drained amount... and start filling from there. I know the 5mt fills from the dipstick... is it the same deal with the 3at? Skishop... are you at Jet Chev? Quote Link to comment Share on other sites More sharing options...
skishop69 Posted July 17, 2012 Share Posted July 17, 2012 It's not a claim, it's a fact and it is better that any prev Dex formula, therefore, the better choice. Not being pissy or knocking you're belief/feeling on the subject, but working with it every day and having tested it in many non GM applications over the past year and talking with the engineers, I have a little more in depth information. Oh, and the 'more heavily friction modified', not true either. Yes, I am at Jet Chev. Do I know you? lol Had a tech from here move to your area I believe... Quote Link to comment Share on other sites More sharing options...
rdweninger Posted July 17, 2012 Author Share Posted July 17, 2012 I've met Steve Venagas. My brother has him work on his S-10 beefed-up version. Also had my 2003 Duramax steering linkage recall work done there. So is Dexron a GM product? Orielly's has Dexron compatible ATF. Quote Link to comment Share on other sites More sharing options...
skishop69 Posted July 17, 2012 Share Posted July 17, 2012 I'm sorry... lmao No, Steve is a fixture here. 20 years. Good guy... Quote Link to comment Share on other sites More sharing options...
86 Wonder Wedge Posted July 19, 2012 Share Posted July 19, 2012 DexII is the old spec of ATF (the P.S. cap says/uses the same fluid). The common replacement is DexIII/Mercon. The fluid is the same, it's the MerconV you've got to be careful with (for newer Fords). DexVI is perfectly ok to use in old Dex/DexII/DexIII systems, however, I've had better results with a DexIII HM (like Castrol's TransMax) since it does have a little seal sweller. FYI, the SYSTEM may hold 7qts, but the pan may only hold 3 or so. Find the "service fill" spec or fill to appropriate level. The rest of the fluid is in the torque converter, trans cooler and line, the valve body and the clutch packs and drums. I would advise just "changing" the 3 quarts from the pan since a total swap may shock the system and cause worse slippage since the junk in the old fluid may be keeping your clutches together! Quote Link to comment Share on other sites More sharing options...
ivans imports Posted July 19, 2012 Share Posted July 19, 2012 dextron 2 updates to dextron 3 same same whant it to work realy good use honda factory atf best atf iv'e seen Quote Link to comment Share on other sites More sharing options...
rdweninger Posted July 19, 2012 Author Share Posted July 19, 2012 Thank you everyone for the info. I would like to go with a good quality ATF... like the Honda stuff. So how would a guy get all the fluid out of the system? If it hold 7 qts, and only 3 qts drain out... that leaves 4 qts... and now I'm faced with 'mixing' brands and quality. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted July 19, 2012 Share Posted July 19, 2012 (edited) Some people do multiple drains and refills. I like to drain from the pan drain plug, then pull one of the lines going to the radiator cooler, pour say 5 quarts in the dipstick tube, start it up and let a quart or two pump out, shut her down, then add another quart or two in the dipstick tube, and repeat a few times until what's coming out looks fresh. It's not perfect since there will still be some mixing of fluid but it's a fairly easy way to do it. Dexron VI is typically backwards compatible for GM automatic transmission applications, but it is not backwards compatible for all applications that called for earlier specs of Dexron. Edited July 19, 2012 by porcupine73 Quote Link to comment Share on other sites More sharing options...
rdweninger Posted July 19, 2012 Author Share Posted July 19, 2012 Thank you Porcupine... that's what I'll do then. I'm not having any problems with the AT... but I'm sure it is the original fluid since 1985. Quote Link to comment Share on other sites More sharing options...
Quidam Posted July 19, 2012 Share Posted July 19, 2012 Thank you Porcupine... that's what I'll do then.I'm not having any problems with the AT... but I'm sure it is the original fluid since 1985. IIRC, last one of these I did, put it up on car ramps pulled the pan and filter off and just let it sit untill it stopped dripping. It took a while but I put just shy of 4 quarts in to refill. If that pan hasn't been off since new, you'll most likely find a pile of stuff in it that should be cleaned out. Most likely it has a magnet laying on the bottom of the pan. Of course this "may" require a new gasket, but the filter is cleanable and reuseable. No big deal to drop the pan on these but not doing it is easier. Your call, of course. hth Doug Quote Link to comment Share on other sites More sharing options...
skishop69 Posted July 23, 2012 Share Posted July 23, 2012 Again, Dex VI is backwards compatible with ALL systems that took any form of Dex. Honda fluid is great, but there can be compatibility issues. If you had the guts to put non spec fluid in your trans and it's worked great, I'd say no worries. Personally, I learned my lesson long ago with doing that. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted July 23, 2012 Share Posted July 23, 2012 Not to beg to differ points that aren't directly related ... but right on the bottles it lists not to use it in certain power steering or differential applications that called for older specs of Dexron. Also some transmission makers such as Allison have not approved Dexron VI for use in their applications that used to call for a previous spec of Dexron. Quote Link to comment Share on other sites More sharing options...
skishop69 Posted July 23, 2012 Share Posted July 23, 2012 Agree on NON transmission applications (I was speaking trans only), however, Allison has approved it. Initially they did not as they are no longer GM owned and weren't privy to the 'inside' specs and weren't going to approve it til GM ponied up. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted July 24, 2012 Share Posted July 24, 2012 Oh ok thanks. Yes plus since Allison has their own fluid they license they probably would rather not have too many approved alternates. Quote Link to comment Share on other sites More sharing options...
skishop69 Posted July 24, 2012 Share Posted July 24, 2012 Right. They got really anal when the new CEO took over after the sale. They now have to have the VIN # from the vehicle, the exact transmission model and build and TCM number just to get a TCM. Funny how we never needed that crap when we owned them. lol Quote Link to comment Share on other sites More sharing options...
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