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ATF vs. 90w - my results

Discussion in 'Drivetrain' started by Chuckanut, May 14, 2007.

  1. Chuckanut

    Chuckanut Guest

    While I had my car in the air this weekend, I decided to change the tranny oil. Since I bought it last year the shifting has been slow, especially in the mornings when it's cold. The 3rd to 2nd down shift was always bad, lots of graunching noises. Three teens learned to drive using this car, so I figured the gearbox was due for replacement.

    Lo and behold, it was filled with 90w gear oil! I refilled it with AMSOIL synthetic ATF and the difference was miraculous! It shifts smoothly all the time, hot or cold, no synchro grinding, I can slide it in first even while moving (I could never do that before), and the shifts are way faster. It's like a new tranny.

    Anyone wondering which oil to use in their tranny, I recommend ATF. That's what they're designed for and I gotta believe the extra thickness of the 90w slows the synchros way too much.

  2. mephtar

    mephtar Well-Known Member

    sounds like i may want to look into that, mine isnt that bad but grids 4th if you shoot it in
  3. zak062

    zak062 Well-Known Member

    what oil would i want to use for my st165? o, and this is kind of dumb, but where do i put it in :oops: .
  4. Chuckanut

    Chuckanut Guest

    We use ATF. I'm a huge fan of synthetics, so I recommend them as well.

    The drain plug is on the end of the tranny just inside the drivers wheel well, and filler is on the front of the tranny (facing the bumper) and about halfway up.

    To change it, drive the car to get the oil nice and warm. Then remove the plastic undertray on the driver's side (10mm bolts), remove the drain plug (it's a 25mm bolt, or 15/16"-1") and let it drain into a pan for about an hour to get every last drop. Put the plug back in (wiping everything nice and clean beforehand so it seals well), and then remove the filler plug.

    To fill it you'll need a funnel with a long flexible hose. It takes 2.7 qts., so pour in about 2.4, then slowly pour it in until it starts to come out the filler hole - that means it's full. Replace the filler plug and the undertray, and enjoy your smooth shifting Celi!

  5. SpeedDemon

    SpeedDemon Well-Known Member

    Damn Jeff has 80-90 wieght in his tranny and I think thats what I have in shantels. This weekend we are going to try royal purple ATF in jeffs car see whats up. It grinds when you shift in real fast and it grinds. Also it grinds from 3ed to 2nd unless your not moving.
  6. Youds

    Youds Well-Known Member

    im running 85 140.... smooth shifting is for girls.....

    its all i had at the time i did my axle will be puttin atf back in when i do the pass. axle ;p
  7. Chuckanut

    Chuckanut Guest

    Sounds exactly like mine. It was such a blast driving home from work today not having to baby the shift lever. Sure is a lot cheaper than replacing the tranny!

  8. zak062

    zak062 Well-Known Member

    questions, ATF?

    yea....ts kindof hard to warm up the trans oil when the trans is outside the car, lol.
  9. JoeJack88

    JoeJack88 Well-Known Member Super Moderator Donated!

    automatic transmission fluid
  10. underscore

    underscore Well-Known Member

    and not AnTiFreeze
  11. zak062

    zak062 Well-Known Member

    lmao... i should of figured ATF= auto trans fluid.

    dur da dur
  12. underscore

    underscore Well-Known Member

    a kid poured a bottle of it into his rad, then asked the teacher for some more to finish filling it up. Now since antifreeze comes in those big 4L jugs he was like wtf did you use? so we checked and sure enough the kid poured a bottle of ATF into his rad.
  13. Gurr

    Gurr Guest

    Just so you all know, ATF is NOT MADE FOR YOUR TRANS! It actually lowers the life of your synchros and other soft metals in the trans which the 80w90 protects. I know there are synthetic 80w90's you can put in which I would suggest over ATF anyday. You aren't going to see damage right away with using ATF but it does not protect the softer metals nearly as well.

    Other than that, you can use ATF I just hope you understand what you're getting yourself into.
  14. SpeedDemon

    SpeedDemon Well-Known Member

    Factory books say ATF is what is suppose to go in there
  15. Chuckanut

    Chuckanut Guest

    Our transmissions are designed for ATF. Read the owners manual and tech service bulletins. In fact, most Japanese front wheel drive trannies use ATF.

    I remember seeing this for the first time as a mechanic in the late 70s on a Honda Accord and not believing it. As soon as I drove it with 90w I became a believer - it was awful to drive and would barely shift. I've done tranny oil in a number of cars since and always use ATF when the manufacturer recommends it.

  16. Youds

    Youds Well-Known Member

    ya every manual or lubrication guide points to atf ;p i as well didnt believe it :)
  17. racerb

    racerb Well-Known Member

    When we rebuilt the tranny in my GTS, you know new sincros and such, we switched to 75w90 synthetic gear lube, works great for track use. I've always been a little leary of ATF in a manual box, but for the street I'm sure it's just fine.

    By the way my transmission guy was the one that recommended regular gear oil after the rebuild.

  18. Chuckanut

    Chuckanut Guest

    Just curious if anyone's changed from gear oil to ATF, and if you saw the change I did.


  19. mephtar

    mephtar Well-Known Member

    did anyone have any luck fixing the gear grinds with new fluid? if I grind on 4th above 2000 rpm and 5th above liek 4000 what woudl i try putting in?
  20. rye

    rye Well-Known Member Donated!

    a new transmission!

    (i'm a smartass :) )

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