Trans oil for 308GT4

Discussion in '308/328' started by Watry, Aug 8, 2005.

  1. Watry

    Watry Karting

    Aug 8, 2005
    Berkeley, CA
    Full Name:
    Andrew Watry
    I just bought a 75 308GT4 (this is my first post), which has blue synthetic, I guess, trans oil in the gearbox and transfer gear housing. Redline? Swepco? The PO didn't know. This trans was rebuilt about 12 years ago with nominal mileage since then. Synchros are good, but the shifting gets a fair amount stiffer, especially into first at rest, as the trans warms up. Is synthetic the right thing to use? I'm used to Alfa synchros, which need a fair amount of friction to work, and so synthetic is not the thing for them; too slippery. What's recommended for a 308 trans? Thanks a lot.

    Andrew Watry
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  3. 208 GT4

    208 GT4 Formula 3

    Dec 27, 2003
    Brighton (UK)
    Full Name:

    I had some problems with my gearbox, which I initially tried to address by trying various transmission oils and additives. I had a similar problem, which turned out to be too high an oil level, and too thick oil in the gearbox. It made it difficult to change into 1st or reverse at standstill having slowed down to rest.

    Eventually I had the gearbox rebuilt, and subsequently it runs best with a synthetic oil.

    The gearbox and diff both use the same oil system by the way. So you can't have different oils for each.
  4. 308ROB

    308ROB Formula Junior
    Silver Subscribed

    Aug 14, 2004
    The Netherlands
    Full Name:
    Hi Andrew,
    Welcome on board, may I request you to use the " Search " button on the top left side of this page and fill in " 308 gearbox oil " there you will find a lot of information regarding your question.hope this will help you.Regards 308ROB
  5. Watry

    Watry Karting

    Aug 8, 2005
    Berkeley, CA
    Full Name:
    Andrew Watry
  6. Birdman

    Birdman F1 Veteran

    Jun 20, 2003
    North shore, MA
    Full Name:
    THE Birdman
    I think you will find that most 308 owners prefer Redline 75W90 NS.

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  8. gerritv

    gerritv Formula 3

    Jun 18, 2001
    St Catharines
    Full Name:
    Hi Andrew
    Welcome to the wonderful world of GT4's.
    I had shifting problems, esp. into 2 and 3 at high revs. Switched back to Non Synthetic 75W90 and those problems are gone. Previously I was using AGIP Synthetic.

  9. marankie

    marankie Formula Junior

    Aug 30, 2004
    Agoura Hills, Calif
    Full Name:
    Suggest Swepco 201. Non synthetic and has the required limited slip additive allready in it. The synthetic stuff is too "slippery" and does not allow the synchros to bite. Result: balky shifting. Very popular with the early Porsche 911 crowd and on the race track.
    Martin Jansen
    So Cal.
  10. pete04222

    pete04222 Formula Junior

    Nov 1, 2003
    Maine, USA
    Full Name:
    Peter Cyr
    The Red Line 75W/90 took care of all my shifting problems.
  11. ProCoach

    ProCoach F1 Veteran

    Sep 15, 2004
    VIR Raceway
    Full Name:
    The blue, if it is opaque, may be Redline "Shock-Proof."

    I recommend Redline 75-90 NS (non-slip) because the conventional Redline 75-90 may make the LSD plates shudder and groan too much.

    Twenty years ago, I was an LE (Lubrication Engineers) Almosol junkie with my first Ferrari, a GT4!

    Agree that if the synthetic does NOT improve shifting ease, use conventional GL-5 Castrol 85W-90...

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  13. CliffBeer

    CliffBeer Formula 3

    Apr 3, 2005
    Seattle, Washington
    Full Name:
    Redline actually suggests using an equal combination of the 75/90 and 75/90 NS in the 308/328 and Mondial as the gearbox and diff have common oiling. I have followed this suggestion and shifting is much improved over non-synthetic, particularly on cold mornings.
  14. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    Full Name:
    Steve Magnusson
    I just changed over to Royal Purple Max-Gear 75W90 gear oil, and it's dyed a purple color -- so that might be your "blue" color Andrew.

    Don't know if this is model related, or if these F gearbox are just so individual that different cars get different results, but I was not impressed with the Redline (although I know many others have reported good results -- and I believe them). Tried the Redline 75W90NS and the shifting was fine, but the limited slip chatter wasn't just noticeable -- it was unacceptable. Added 4% by volume of the Redline Friction Modifier (which I believe is equivalent to the Redline 75W90) and this reduced the LS chatter to acceptable, but it was still noticeable. With the Royal Purple -- absolutely no LS chatter and the shifting feels even better (so I'm happy ;)).

    Just another data point...
  15. teveo

    teveo Formula Junior

    Oct 1, 2005
    Full Name:
    Trond V
    Steer away from Swepco 201 unless you live in very hot climate.
    I just served my GTS with Swepco and the tranny is too hard to shift ( we have 5 - 15 degrees celsius now). I am going to try Redline and keep the Swepco for my Porsche cars ( great in the Porsche gearbox ) .
  16. thecarreaper

    thecarreaper F1 World Champ
    Silver Subscribed

    Sep 30, 2003
    Full Name:
    well, its hot here in Georgia, and i can add my dino and one of my other 308's got swepco 201 in them, and they shifted great. i like the blue color as well, as i know where any leaks are! we drive our cars year round here, and although i used red line several times, i did notice the " balkiness " like it was " too slippery". not to sound like the 3 bears fairy Tale, but swepco in my Ferrari's was "just right"!

    i have some already for when my QV is due.
  17. James in Denver

    James in Denver Formula 3

    May 23, 2006
    Centennial Colorado
    Full Name:
    James in Denver
    +1... On my old QV, the PO put in something with additives, it was "ok" to shift, but not great. My mechanic (the BEST btw) replaced with Redline 75W90 NS and commented "this thing shifts like one of the best i've felt" after his test drive.
  18. teveo

    teveo Formula Junior

    Oct 1, 2005
    Full Name:
    Trond V
    I changed to a synthetic 75-90 oil today, car shifts perfect but the Swepco experience blew (or cleaned out) my diff seals and now I have to do install new seals. Oil was seeping a little before, now it leaks hefty and the passenger side spray the manifold, it smokes..

    Winter is approaching so I will do this while also doing rear suspension bushings, anyone have a link to a diff/seal rebuild?
  19. Glassman

    Glassman F1 World Champ
    Silver Subscribed

    I was just wondering if seal leaks was a problem with the Redline. I changed mine last summer and noticed more oil on the floor and a lot of oil on both pans.
  20. robertgarven

    robertgarven F1 Veteran
    Rossa Subscribed Owner

    Feb 24, 2002
    Ventura, California
    Full Name:
    Robert Garven


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