[urq] Re: flaky breaky audi

[urq]

... MT-90 is rated GL-4 ... I don't think anyone would offer a GL-5 fluid
for manual transmission (MT) apps due to possible damage to the synchros.
That said, Red Line must have less caustic additives, because it seems that
they indicate that their GL-5 gear oil can be used in transmissions.  Red
Line actually has a fairly informative site:

    http://www.redlineoil.com/products.htm

Years ago I contacted RedLine and their apps person recommended MT-90 for
the transaxle and the 75W/90 Gear Oil for the rear diff.  I compared the
specs that Audi gives ... per Bentley ... SAE 80 or SAE 80W/90 hypoid Mil
L-2105, API/GL4 for the transaxle and SAE 90 hypoid Mil L-2105B API/GL5 for
the rear diff.  I actually decided to use the Red Line 80W140 Gear Oil in my
rear diff.  To my mind, I'll take a 0.5% efficiency loss for the chance of a
little more protection.

I did have the synchros in the 5KCSQA go after I changed the fluid in the
transaxle to MT-90 ... but I think that it may have also been due to the
fact that I did not recheck the fluid level after my initial fill ... I
found the fluid level was well below the fill point after the oil had a
chance to flow back to the center diff.  Who knows for sure on what caused
the failure ... I will say that the switch to Red Line really did improve
the ability to shift when cold ... and the transaxle in the urq is still
doing fine with MT-90, which it has had for a number of years.

HTH & IUD!
Steve Buchholz
San Jose, CA (USA)
>
> > Redline MT90. If not, a synthetic gear oil with a GL4 rating (not GL5!).
> > Ask me how I know.....
> >
> > BTW, Redline MTL is too thin.
> >
>
> That is most distressing, as I just filled the URQ tranny with MTL 2 weeks
> ago.
> So how long before the tranny is toast?
> The distributor where we purchased the Redline was very confusing in it's
> display and pricing. I found Redlines labeling to be less than clear as
well.
> I was under the impression that the MT90 was GL5 rated.