transmission oil

[65giulia101]

I have a 65 giulia 101 what is the recommended tranmission oil to use

[papajam]

The owners manual says either Shell Dentax 90 or AGIP F.1 Rotra SAE 90. This is for the stock gearbox with non-moly syncros. If the box has been converted to moly syncros or a later box (1968 and on), then Alfa recommends either Shell Spirax 90 EP, AGIP F.1 Rotra Hypoid SAE 90 or ESSO Gear Oil GX 90.

[65giulia101]

thank you for the info the problem is I am not sure what type of syncros are in it is there an easy way of checking without pulling the tranny

[GTD]

aaaaaaaaaaaaaaah, no.

[65Sprint]

I have the same concerns regarding syncro type in a 65 Guilia Sprint. Does your transmission have a red sticker similar to the one in the first picture (Use Only Oils Type EP)? I am thinking this may indicate a change to the later syncronizers if I am interpreting the manual correctly.

[Alex]

Are there any ways to visually check which synchros are in the box, assuming that it has been stripped down? I remember reading in the Digest a long time ago something about a circumferential groove in the ring, but my mind may be playing tricks on me (again )

Which is the superior version? And if an early box was to be converted to the later synchros, are there any other bearing etc surfaces which would be incompatible with EP oil?

And I'm not even going to attempt to ask what the differences between Spirax and Dentax oils are!

[Giulietta10103]

Some info:
Shell Spirax HD gear oils are extreme pressure, multi-grade, multi-purpose mineral oil based lubricants for heavy-duty truck and automotive differentials, manual transmissions and oil lubricated wheel bearings.

Shell Spirax S lubricants are synthetic, extreme pressure fluids recommended for manual transmissions, differentials and transfer cases in severe service. Excellent for extended drain requirements. Spirax S Lubricants meet Eaton Extended Warranty requirements.

Shell Dentax Oil is a gear lubricant designed for manual transmissions where the manufacturer specifies either a "straight mineral" oil or an oil meeting API Service GL-1. A time-tested additive system inhibits oxidation at high temperatures, maintains excellent flow in cold temperatures, and controls foaming.

Shell Dentax S Transmission Lubricant is a fully synthetic, transmission lubricant for use in automotive manual transmissions. It is designed for extended drain and severe service in heavy-duty manual transmissions that require a "straight mineral" or non-extreme pressure oil. Dentax S Oils contain additives to inhibit oxidation caused by high temperatures, and inhibitors to help prevent rusting and corrosion. Shell Dentax S 50 is approved by Eaton and Rockwell International for extended drain/warranty applications.

Shell Omala Oils are versatile premium-quality oils designed to lubricate industrial gear units where an extreme pressure type of oil is required. Omala Oils are industrial gear oils and are not intended for heavy-duty truck or automotive applications. Spirax Oils should be used in heavy-duty truck and automotive applications.

[gowanusvin]

The earlier synchros have a number of grooves running along their circumference, much like a decorative bracelet.

the newer synchros are smooth surfaced, with a sllightly rough feel to the touch.

newer synchros on older transmissions--like my 63 guilia spider five speed--require different sleeves and other bits called straps and quadrants or else won't work correctly.

[AlfistiSA]

Good answers guys - great info 10103

Basically Spirax is an EP, (extreme pressure), oil, with additives, while Dentax is a straight non additive mineral oil.

If in doubt, use Dentax - Spirax oil in a Dentax box, results in the oil being too "slippery" for the synchro's & they don't work. Apparently several successive flushes of Dentax will restore the synchro's, but it's not something I'm keen on attempting.

The later EP boxes usually have an oblong yellow decal affixed to them saying EP Oil.

Cheers
Greig
With a 20L drum of Dentax under the bench...

Some 750's
Some 101's
Some 105's
Some others

[kengta]

Here are three pages indicatiung differences between early and late transmisions. I am trying to post some pictures showing to parts side by side.
I have converted a GTA trans to All moly from part moly including changing the Synchro hubs that are pressed onto the gears.

Regards

Ken Geiger

[gowanusvin]

Not sure the Yellow decal says use EP oil

According the chart posted above the RED decal (translated as "transfer") indicates EP oils

However, my memory is failing--I remember Yellow as NON-EP.

Can someone else check?

[AlfistiSA]

Hi Gowanusvin

The yellow decals may be a South African decal, as we had a factory out here assembling CKD Alfa's. All the later GT Juniors have a yellow decal on the side of the box.

Guys take note that the decals applied to US gearboxes are red.

When in doubt, please read what the decal actually says !!

Cheers
Greig

[gowanusvin]

Good point Greig!

Of course, someone has to explain the logic of using different colored decals with the same warning in different colors.

Does yellow mean stop, below the equator?

[AlfistiSA]

You have to stop ???

I'm busy building workshop & garages at the moment, but in the next 3 months, all my cars will be coming home & I can take & post a pic of the decal if anyone wants ??

Cheers
G

[gowanusvin]

Actually, my U.S export 1966 Giullia Sprint GT had a yellow sticker, no doubt a play on yellow peril.