Ferrari Mailing List: Re: GT4 video...

[Hans E. Hansen (FList]

For syncros, thin is better, and Limited Slip additive is bad.
For the diff, thick is better and LS additive is good.
For a transaxle, you are essentially screwed.

Syncros need some friction to work.  They are essentially a
clutch and the cone and the ring need to grip each other.
If a super slippery lubricant doesn't allow them to grip, then
the result is usually grinding.

The LS diff has friction plates that must slip in order for the
car to properly turn corners.  Regular lube isn't slippery
enough, so a LS additive (either already in the oil or added
afterwards) is used.  Usually you keep putting in the additive
a little at a time until the diff no longer chatters or makes
grinding-like noises.

Hans.

On 1/21/08, JIM WILCOX <jimshadow [at] verizon.net> wrote:
> My understanding is that the newer oils with slip agents are (for lack of
> better descriptors)  "too thin"  and that's why there is more in the way of
> issues vs. the NS fluids in the 308 trannys.  Also, the synthetics allegedly
> have great cleaners in them that wash away the crud that may be holding back
> any leaky seals, etc.....AM I CORRECT IN THIS THINKING OR AM I WAY OFF?????
>
> I"m having the exact OPPOSITE problem as you Hans.    My car always had
> Redline in it.  After the accident/drop gear issue it came back to me with
> Mobil 1 in it and now I get 'chattering' in 4th and 5th.   If I'm too
> aggressive 5th will grind.    I never had those problems  with RL.    The
> next warm day with no salt on the roads, I'm changing out the tranny fluid
> to all Redline 75/90NS.
>
> JIM
>