LSD oil for cusco clutch type

Discussion in 'DRIVETRAIN' started by fastglanza, Sep 13, 2007.

  1. fastglanza

    fastglanza Registered User +

    Can a LSD synthetic oil be used in the cusco lsd's? I know KAAZ says not to use a synthetic fluid. And most other brands like Motul etc have their lsd oils as mineral based and not synthetic.

    Im trying to find cusco's oil but no luck..I've found the KAAZ oil which will work fine but I can get the synthetic oil locally (AMSOIL)
  2. sx_turbo

    sx_turbo Paid Member


    i have been doing some research today, and cusco say you must use mineral oil just like kaaz, so i would assume all mechanical type lsd's are the same,

    do not listen to oil man he will tell you to use synthetic, this is wrong you need to use a high qaulity mineral oil, with the lsd addittive in it.
  3. oilman

    oilman Registered Trader

    I would listen to oilman, he knows what he is talking about.

    Most synthetics are in fact mineral oils!

  4. goldenvtr

    goldenvtr Paid Member

    oildude - what oil do you recomend for a clutch type diff that clunks like hell?
    im currently using silkolene 75/90 syn5

    thanks in advance :p
  5. sx_turbo

    sx_turbo Paid Member

    well i have put some cheap stuff in mine and added the friction modifyer, and it's now much quieter than the silolene syntran 5 you told me to put in.
  6. weakboy2

    weakboy2 Registered User +

    probs cos its wearing out!!

    sod putting cheap oil into my gearbox!!!! after a few trackdays it would be dead!
  7. oilman

    oilman Registered Trader

    Quieter maybe, better... maybe not.


  8. sx_turbo

    sx_turbo Paid Member

    a brand new diff thats done 2000 miles, and most of those miles were just running in lol.

    i will be buying the kaaz and cusco oil in the future, just wanted to try the cheap stuff through work rather than waste money on the cusco/kaaz stuff incase it didnt work.

    the oil needs changing when the engine oil needs changing anyway,
    Last edited: Sep 22, 2009
  9. oilman

    oilman Registered Trader

    The trouble with these after market mechanical diffs is it then creates a conflict of interest oil wise, the diff and the gearbox so a comprmise is needed. I tend to favour the side of the box but thats just me.

    The reason a mineral is recommended by the oem is not because a synthetic will brake it, its because mineral oil does two things, hides the chatter noise and makes the diff more user friendly especially for daily use, as in if you use a synthetic it will encourage the diff to lock more harshly and quicker and many people dont like this, its not doing any harm its just how you like your diff to perform.

    If you use a decent gear oil then add friction modifier bit by bit you can get the diff to react just the way you like. Very common practice in race applications as all driving styles are different, personally I prefer harsher the better.


  10. starlet666

    starlet666 Registered User +

    i was going to say something along the lines of the earlier post about most synthetics being mineral oils..... if u do find a "genuine" synthetic.... u will just b using a mobil product anyways :)

    mobil own the right to the fully synthetic product label i believe

    MARK@CMBAUTOS Paid Member

    i run ls80w-90 limited slip gear oil on my cusco clunky diff and its not that bad :) is say on the rear of the bottle . a high quality,mineral based,extreme pressure with friction modifier for smooth operation of limited slip differentials
    Last edited: Sep 26, 2009
  12. scot-ish

    scot-ish Paid Member

    Limited Slip Friction Modifier

    Compatible with petroluem or synthetic gear oils, this product will significantly reduce the friction break-in of differentials, reducing break-in temps for as much as 50 degrees F. Limited slip or positraction units will often chatter without use of this product or a gear oil with a similar modifier, so add only enough to eliminate the chatter and avoid making the plates or clutches too slippery.

    from the website, reduces the "clunk" from the diff i believe
  13. Rory

    Rory Paid Member

    When i had the Cusco diff, i ran the Silkolene 75/90 Synthetic stuff with a little of the Redline friction modifier thrown into the mix.

    Run fine, but noticed the box getting a bit notchy after a while.

    So went and bought the Quaiffe unit. Far better in my opinion. :)
  14. madman

    madman Registered User +

    or how about you use the proper stuff :D clicky
    Last edited: Sep 26, 2009
  15. scot-ish

    scot-ish Paid Member

    is that the link you meant?? :freddy:
  16. fastglanza

    fastglanza Registered User +

    wow a really old post there lol...

    well now i only use the kaaz oil since i find it easier to get over the cusco one..

    but my decision was made from noticing the diff getting very worn after using the synthetic oil..also the gearbox started grating on gearchanges. (this was after each track race season)

    but havent noticed any probs since using the kaaz oil and its been a while too
  17. madman

    madman Registered User +

    link fixed

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