Re: Giulia gear oil?

[bearbvd@domain.elided (Greg Hermann)]

>Put the GL-1 in the tranny and the GL-5 in the diff. If the tranny has been
>rebuilt with modern synchros, or a late model gearbox has been fitted, then
>you can use the GL-5 in both.
>
>Here's a good question for the historians and those with a parts book
>handy. When did the old style synchros that required the GL-1 oil stop
>going into new cars? AFAIK, the only part that changed was the synchro
>rings themselves. Looking at them, the old style ones have grooves, and the
>new ones have a mottled surface with no grooves. I'm guessing the cutoff
>date for the old ones was around 1969-1970.

Pretty close as to the time of the change. At the time, the new style
synchro rings were called "Moly", which I assume to have meant that they
were coated with molybdenum. As I recall, the Alfa people of the day
claimed that you needed to change not only the rings, but the inner
bits--and _the_gears_!

You are absolutely correct as to the oil--the old style rings will NOT work
worth a %$^&* with EP type gear oil. The new style will tolerate EP oils,
but will work with either type. EP type oils are only really needed for a
hypoid type ring and pinion gearset--as is usually incorporated in
transaxles/rear axles. This is true because some sliding contact between
the gear teeth is present when a hypoid gearset meshes. The AMOUNT of
sliding contact which exists increases as the distance that the pinion
centerline is below the ring gear centerline increases.

The change to the synchro rings was not so much because the gearbox is any
more durable with an EP type oil installed in it--in fact _IT _MAY_ BE_LESS
_ so! The change was made more because there were so many incompetent
grease jockeys in the world who just added EP type oil to everything under
a car without thinking about it.  And then poor Alfa was stuck with the
reputation of a mfgr. who could not make synchros last more than 10K miles!

Having used both--I have always felt that an Alfa box with the old style
synchros and the correct (straight mineral) 90 weight gear oil in the box
(but with the newer, FAR more rigid shift forks, and the later, roller type
center layshaft bearing) was one of the better shifting gearboxes ever
built anywhere!

Regards, Greg

>
>Carl750 wrote:
>
>>For Giulietta and Giulia all the manuals say is 90 in the gear box and 90
>>EP in the differential.  Today everything is GL 1 or GL 5.  Can somebody
>>translate.

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