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Discussion Starter #1
Some years ago, the gearbox on my Giulia started grating really badly, obviously it had enough of the abuse I had meeted out.

Laurie Steyn from Alfa Clinic here in Johannesburg suggested a very special (and expensive - it cost US$10 for 500ml 10 years ago) Castrol gearbox oil. I cannot remember its name, but if I remember correctly, its name consisted of 4 alphanumeric characters, something like AP21 or whatever. I really cannot even vaguely remember the name of this oil, all I can remember is the 4 alphanumeric characters.

In any case, this stuff was like a gearbox overall out of a bottle. The grating just vanished!

But then, at a service, the gearbox was drained and we found out that this special oil was no longer available from Castrol and Castrol South Africa could not tell us what to use as a replacement that would have the same properties. This oil was made for Ford for their first front wheel drive cars (British Ford Estcourt) where the gearbox and diff was one unit. Unfortunately, this oil was discontinued as it was found that for the Ford application, normal SMX was perfect for that application. Castrol South Africa Technical reps were not really interested in one-off enquiries and could not really offer much else in the way of suggesting an alternative.

We put SMX in the Giulia's gearbox, but it did not have the same effect as that original product from Castrol.

Does anybody know what else could do the trick, maybe from some other oil company? After all, its is a lot easier and cheaper than a gearbox overall.

Malcolm
 

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Can you get Redline

Try Redline MT90. I'm running it in my Giulia Super. It's fabulous. It's synthetic, but has the friction properties to make the syncros work. Threre may be issues with the materials your Giulia uses for its syncros, but I think the right synthetic, with friction additives, should work quite well.

I'm running the 75w90 Redline in my differential (it does not have limited slip). If you have a limited slip diff, you have to have the right friction package.
 

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Try Redline MT90.... .
Only if you want it to leak like a sieve IMO. Got a drip leak from using MT90 in my Nissan DD's transaxle. Still leaked after replacing the transaxle seal. Am now adding good ol' GL4 rated dino gear lube as a filler and the leak is eventially going away. Your choice.
 

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Beg to differ

Only if you want it to leak like a sieve IMO. Got a drip leak from using MT90 in my Nissan DD's transaxle. Still leaked after replacing the transaxle seal. Am now adding good ol' GL4 rated dino gear lube as a filler and the leak is eventially going away. Your choice.
Oops. Something is not right here. Synthetics do not cause leaks, bad seals and cracked cases or similar failures cause leaks.

Anyway, doesn't every Alfa come with an external lubrication system? Isn't each Alfa simply expressing it wants special attention, all of the time... to keep things running properly!
 

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Not trying to start an argument, but...

Don't count on it - IMO of course:)
Think about the concept and/or myth that synthetics create leaks... because they have a tendency to disperse (and sort of clean up) sludge, which has formed at the seal, or along engine, block, crankcase, differential etc. mating surfaces?

Synthetic is oil. It is simply an oil whose base stock is more consistent in its molecular structure, with additive packages for stability, viscosity, heat tolerance, lubricity, and a host of other features. But it is in fact oil, just like dino oil. So by its nature, it shouldn't cause leaks. The leak had to be there because of a need of a gasket, or worn assembly gasket material. The protections afforded by synthetics are worth the trade-off to me. As we drive 40 year old cars, it's part of the process to change those seals and fix those leaks... until they show themselves again, and we continue with the process of topping up our fluids.

It's kind of like an AA meeting requirement. Yielding to a higher power, and admitting, "my alfa leaks oil and transmission, differential, and steering box lubricant... but it doesn't leak brake fluid (today)."
 

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What year is your Giulia? Sometime around '67 Alfa upgraded from non-moly to moly syncros. The older non-moly syncros specified Shell Dentax oil whereas the later used Shell Spirex. Modern oils do bad things in the older boxes. Typically the older trannys will have a yellow sticker (non-moly) and the later a red sticker (moly) on the side. To confuse matters further, some older transmissions have been converted to moly syncros (not a simple task). You can tell which syncros you have by putting the car in neutral and looking into fill plug opening to see whether your syncro rings have ridges (non-moly) or not (moly).

Bill
 

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Discussion Starter #8
My Giulia is a 1975 1600 Super Nuova, so I should be able to use a modern oil.

As I said, I did use Castrol SMX, which I think is a synthetic oil. SMX did not do what I had hoped it would.

Gearboxes take little enough oil, maybe I should just drain and refill with new oils until I find one that yeilds the required results.

Malcolm.

PS
We have a public holiday today... It is National Women's day here in South Africa. Just lazing around in the late winter sun, recovering from a cold front that passed here on Tuesday.
 

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I'm with Ish-Man here: mine has Red Line MT90 in it and it's excellent. And it doesn't leak. Come to think of it, it's the *only* thing that doesn't leak.
Angus.
 

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Malcom,

What do you mean when you say "grating"?

My box was just completely rebuilt by an reputable Alfa shop and it is some what noisey. Especially with the drivers side window down and in second and third gears when warmed up. It functions perfectly, just noisey IMO.

Note: inside the car is fine, so it's not a matter of trans tunnel boots and seals.
 

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My vote is for Red line MT-90 also. Used it in the '71 trans (from a parts car!) installed in my GTV. This is the best shifting Alfa trans that I have ever owned. AND no leaks!
The 1750 with Castrol GTX leaks like mad!!
 

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Discussion Starter #13 (Edited)
Grating = Gears grating in up and down shifts.

This is due to shot syncro rings, a result of changing too quickly (crash changing) in traffic light "Grands Prix". If not seen to, could require new gears due to gear damage.

Only solution would normally be to replace syncro rings, but it seems like some oils make even the shot syncro rings work like new ones.

I have the same problem on the box on my 1969 1750 Berlina. Both of these are as a result of racing. I used to race both cars in track racing during the 80's and 90's. I have not used the cars much since then, but now that the sons are old enough to drive, I want to get the two cars in tip top shape again. The only problems are the syncro rings in both cars, the Giulia being by far the worst of the two.

Malcolm.
 
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