Alfa Pages

[Oggie]

Hi , can anyone recommend a decent gearbox oil and let me know why you like it, changing mine at the mo and although the old oil was of a decent colour it smelt like an open jar of pickled onions!
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PHAT 33

[Brit01]

I have the same question.

Had motul hp moly 80w90 in and after two years it feels terrible.

Seen some motul 75w90 synthetic locally.

Worth trying?
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S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi)

[ZeNiTh-PbArM]

Hi,

I did use Castrol 75W90 for a time.
Now I put Total 80W90 and the gear lever is smoother to operate in cold condition (however strange this may seem!). Hot behavior is the same.
I flush every 40 000 kms.
Don't worry about the smell - it's common to all gearbox oils!
Hope you have access from underneath the car as it is kind of difficult from the above (I ended up hooking an extension hose to the filler plug to avoid operating the syringe from under and getting soaked in oil in the process)

regards,
zp

[JeremyC]

Redline MT90 without a doubt.

Previously used in other cars to great effect and I changed the 33 to it about a year ago and noticed a significant improvement in change quality particularly when cold.

It's not cheap though, it will cost you about £50 to do the Alfa and I'm not aware of any stockists locally so it will have to be ordered, there are usually ebay sellers with decent pricing.
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'93 Black 33 1.7 16v

[Oggie]

I Used Valvoline Durablend as recommended by AHM, I forgot to mention that I have a Quaife Lsd diff so really wanted to uses an oil that may compromise its performance.
The smell of the old oil was really pugnant, I have changed gearbox oil at least 20 times on various cars but hadn't smelled anything that strong. It was a really acidic smell (like too much vinegar on your chips).
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PHAT 33

[JeremyC]

In light of the diff I'd be picking up the phone and talking to Quaife about i)what oil they recommend ii)what that smell might be.
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'93 Black 33 1.7 16v

[eagle3]

You need a specific grade for an lsd. It's not 80/90 I don't think.
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Alfa33 QO 1984
Alfa33 1.3i.e. 1994

[ZeNiTh-PbArM]

Hi,

If the smell was way more acrid than usual and you have a LSD the root cause is probably the friction plates of the LSD have burnt and debris have contaminated the oil.
Same thing happens in automatic gearboxes when the friction plates begin to slip and burn. The smell is foul and usually referred to as almond / grilled almond / bitter almond smell.

You might want to check the wear on the plates and try to have the gearbox oil run cooler. The easiest thing to do is to have a temperature sensor installed on the gearbox and you might get surprised at the values you read.

Regards,
zp

[Oggie]

Interesting point Zenith, where would be the best place to tap into the gearbox casing?.
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PHAT 33

[ZeNiTh-PbArM]

Hi,

The easiest is to tap through the fill plug - you don't want machining chips to get inside the gearbox. The oil level being lower than the plug, there is an offset between the measurement and the actual temperature.

I've been tempted to use the drain plug instead but that would leave the sensor exposed to road bumps.

I ended up removing the rear gearbox casing (can be done with the gearbox in the car, although it is quite tedious) and tapping through the casing below the oil level.

Regards,
zp

[Bobkelso]

Hi, Zenith,
At next maintenance stop I'd like remove the rear gearbox casing
to replace the rubber o-ring/rubber seal around the command axe
(the axe connected to the gear lever) as it is leaking oil a bit.

It is possible remove the rear gearbox casing
without remove the command axe that is passing through him?
I mean, can I remove only the head of the command axe
(where there is the rubber "cotton shape" bush),
leaving the axe in place, and pull out the rear gearbox casing?
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Alfa 33

[ZeNiTh-PbArM]

Hi,

Yes you can remove the gearbox rear casing in the car like you describe.
It is even possible to replace the lip seal in place on the car with the use of the following tools, one for extracting the seal an the other for pressing the new one in place with a hammer :



regards,
zp

[Bobkelso]

Thanks, clarifying explanation

[Brit01]

Found four options

Valvoline synpower 75w90 -$$$$

Motul 300 75w90 - $$$$$

Motul 75w80 semi. Half the price!
Opinions?

Or I may be able to get Mobil 1 75w90 at trade price from a friend here.
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S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi)

[Brit01]

Really stuck for advice here.

How would the thin 75w80 motul semi work in my box? Too thin when hot?

The fully synthetic is darn expensive. About 20 quid a litre! !
Semi half the price
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S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi)

[ZeNiTh-PbArM]

Hi,

Unless I'm mistaken the manufacturer recommended grade is 80W90.
I'm afraid 75W80 might be too thin ; it is quite uncommon for a drive axle with hypoid gear of this generation to accept 75W80 oil.

I would look for 80W90 which can be had on the cheap (total oil can be had here at 8.3€ for 2 ltrs) or 75W90. I have tested a number of different grades and have to admit that the feeling of the gearstick is better with 80W90!

regards,
zp

[eagle3]

[Brit01]