Shell Spirax diff oil for a 1966 GTJ

[Bertonemorten]

Hello !

Im a bit confused now... What kind of syncros do I have in a 1966 gearbox ? I understand there are 2 different types, what are the differences ? I am planning to use the same oil in transmission an differential as prescribed from Alfa Romeo, is this a good idea ?

[Bertonemorten]

Found a picture of the dismantled gearbox, can anything be seen from that ?. I only renewed the seals at the input and output shaft because the box is working OK.

[Gubi]

Do you have the "Alfa Romeo Owner's Bible"? Read the info on page 155. Per Pat Braden, it looks like Alfa switched from the old "radial groove" synchros to the new "rough surface" synchros in 1968. They're both moly, but apparently the old ones were more picky about lubricant type.

So it sounds like you have the older ones unless it was rebuilt at some point. You might want to ask in the GT forum what folks there are using.

The diff is a lot less difficult. You don't have an LSD, so if the manual says 90 Wt GL-4 then probably any 90 Wt (or 80W90 or 75W90) GL-4 should do a decent job.

[slyalfa]

the old type take a GL1 I think look at IAP for your year.
but there should be a sticker on the trany if the old type.
but if it has been apart the sticker might have went bye bye.
You need to know which type you have.
puting in the wrong oil will trash the syncros.
if you have a pic of it opened did you replace the syncros??
I do not even think you can get the old type any more.
most upgrade to the new type on rebuld.

[Bertonemorten]

There were a sticker on the gearbox (under 5 mm dirt !) saying "Use only EP quality oil" and the manual says a GL4 oil should be used. So that is what I am going to do. I have finally found a supplier (a boat shop !) for Spirax GX 80W-90. I'll try to clean the inside of the gearbox with petrol this weekend by flushing it 2 or 3 times.

[lowmileage]

Quote:

Originally Posted by Bertonemorten I'll try to clean the inside of the gearbox with petrol this weekend by flushing it 2 or 3 times.

[Bertonemorten]

You have a good point there....

[slyalfa]

was that a red sticker or a yellow sticker?
the red take the later oil while the Yellow take the GL-1 (hint big trucks use that oil too)


see
transmission oil

[Bertonemorten]

The sticker was red !

Flushed the gearbaox with petrol this weekend and filled in GL4 oil. Easy job, but i cant feel any difference... The shifting is as soft as before and the syncronisers are working very well...