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ATF vs Gear Oil

Discussion in 'Drivetrain' started by Rick89GTS, Sep 4, 2012.

  1. Rick89GTS

    Rick89GTS Well-Known Member Moderator Donated!

    The BGB specifies ATF for our cars, but just wondering if any have switched to gear oil. If so, do you notice any difference or improvement?
     
    Last edited: Sep 5, 2012
  2. eNtraxGT88

    eNtraxGT88 Well-Known Member Donated!

    70w90 Castrol Syntec, i live by it now. on my old box i had atf and everything would be fine except 5 gear had a crunch, so i swapped to gear oil and the shifts felt tighter and the whole box felt tighter, the 5th gear got better, but not too much.

    stig highly recommends gear oil as well and the BGB also switches out to gear oil 70w90 by the st20x s5x boxes
     
  3. Stig

    Stig ST162 Guru Donated!

    There's threads on this subject - somewhere?
    I've been recommending 80W-90 for years to cure crunchy boxes - all thought I was nuts till they tried it

    The syncros work on fine threads to brake the gears, with worn syncros the ATF is too thin to work as a decent braking agent so the boxes tend to crunch and eat up the rings and gear teeth

    The MR2 and later BGB's all spec 80W-90 for the same boxes
     
  4. Rick89GTS

    Rick89GTS Well-Known Member Moderator Donated!

    OK, 75w90 it is. Any other specs, like GL-5? Thanks guys.
    PS - I think some of the old threads must have disappeared during changeovers and upgrades :(
     
    Last edited: Sep 6, 2012
  5. eNtraxGT88

    eNtraxGT88 Well-Known Member Donated!

  6. Stig

    Stig ST162 Guru Donated!

    Those guys got it mostly right but the LSD boxes don't have a seperate chamber for the diff, that's only found on the auto boxes.

    If your box is still crunchy and slow to find reverse I suggest trying LSD friction modifier in the oil. I haven't tried it but anything that will aid friction in the box will help gearchanges.

    Yeah Rick, there's a lot of usefull stuff missing

    I think Toyota realised at the time they could gain some HP by using thin ATF oil, it's an old racer trick but long term isn't good for syncro's, needle roller bearings, selector rings or forks.

    Open 2 boxes with identical miles and the one run on 80W will always be in better condition
     
    Last edited: Sep 5, 2012
  7. fernandocelica

    fernandocelica Well-Known Member Donated!

    I found a gearbox LSD from a St205 price R1000.00 what should I be looking for starter I have noticed is on the other side can mine fit?
     
  8. Redrkt01

    Redrkt01 Well-Known Member

    Per 1995 BGB RM380E Toyota recommends SAE 75W-90 for the C52, the S54, and the E56

    For the C52 they recommend grade API GL-4 or GL-5

    For the S54 they recommend grade API GL-3, GL-4, or Dexron II ATF.

    For the E56 they recommend grade API GL-3, GL-4, or GL-5
     
  9. eNtraxGT88

    eNtraxGT88 Well-Known Member Donated!

    meant to say 75w90! just checked my bottles of gear oil and they are indeed 75w90! the back of the bottle says it okay for boxes needing GL-3, GL-4 AND GL-5, so that covers me i guess for the s54?
     
  10. Redrkt01

    Redrkt01 Well-Known Member

    I'm not really sure if 70 weight would've mattered all that much. AFAIK you should be good to go with that stuff.
     
  11. Stig

    Stig ST162 Guru Donated!

    For really bad boxes I've seen people use 120W-140 to keep things working but it requires letting the box warm warm up in the mornings before it feels normal

    ST205?? you sure, sorry it wont fit your S53/54
    You'd need to buy a Camry V6 box and shafts and swap over the Camry cover, shafts, starter, cables etc and use the gen2 flywheel/crank
    I don't think ST205 has a front LSD anyway, I know it did have rear LSD
    Your best bet is a V6 manual Camry donor

    You can buy diffs for the S53/E15x on the net for around $1000 new
     
    Last edited: Sep 5, 2012
  12. Redrkt01

    Redrkt01 Well-Known Member

    I think he means to say that he has an ST205 LSD gearbox. Not the LSD individually....because in that case it would be useless for his tranny.

    Stig, at one point TRD offered a front LSD for the E154.....so is that to say it was only an aftermarket option? As for the center diff, it did "act" as an LSD. I don't know what exactly that means, but it is quoted from RM399E.
     
    Last edited: Sep 5, 2012
  13. Rick89GTS

    Rick89GTS Well-Known Member Moderator Donated!

    Put in 80w90 gear oil but haven't noticed much difference yet. Still a bit notchy, especially going into 1st gear, so I shift with a very light touch.
     
    Last edited: Sep 15, 2012
  14. Big3

    Big3 Guest

    Ive gone 27 years in my 86 GTS with what the factory specified - Dexron ATF - and mine shifts like it was new. Id hate to switch after this long from something that works and that is also called for by the factory.
     
  15. Rick89GTS

    Rick89GTS Well-Known Member Moderator Donated!

    A month later and it feels better now. it actually seems to be consistently less notchy. I will keep monitoring it.
    My 89GTS has Dexron ATF in it and is smooth as hot butter.
     
  16. eNtraxGT88

    eNtraxGT88 Well-Known Member Donated!

    after 27 years you may just want to stick with atf since it is what is the factory spec and it's working for your car. but at least now you know if something ever goes wrong with your trans, you can switch it out for gear oil
     
  17. Rick89GTS

    Rick89GTS Well-Known Member Moderator Donated!

    8 weeks later and the gearbox has smoothed out, noticeably better now :)
     
  18. Stig

    Stig ST162 Guru Donated!

    I speak not with forked toungue, doesn't happen overnight but in this world everyone expects miracles
     

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