ALFAGTV6.COM

[ar4me]

Read= This oil is not to be used for Hypoid gears, it will not work.
... This will destroy a hypoid gearset in a hurry.

Mats, you must be confusing things - got 100s of thousand of miles over many years without any issues.
Jes

[Mats]

Well, if you can smell the hypoid additives from a mile away when you open the gearbox you know it's good to use.

I never have used Redline myself as I get the big "Snake Oil Chills" whenever I encounter any of their products. Never heard of a hypoid differential for instance, what the heck do they mean?

[MD]

Side stepping the oils for a moment, here's a simple explanation of gear set types that even JK will understand

Clearly the Alfa transaxle fits the definition of a hypoid differential.

http://www.tpub.com/content/engine/1408 ... 081_61.htm


Hope you are still with us Kevin...

[Mats]

Not really. The Differential is the unit on which the final drive ring gear is attached, the hypoid type final drive has exactly zero to do which type differential is mounted (bevel, in our case).
Probably has to do with the general misconception that the whole rear axle is called "differential".
Not a sign of quality that the oil manufacturer can't tell the difference...

[MD]

Must admit my line of thinking is/was that the ring gear,pinion gear,sun gears,and the lsd components are referred to collectively as the "differential" even though as you say that is not specifically correct and rightly so.

[Giuliettaevo2]

Technically i think the differential exists only of the parts that allow the two halfshafts to rotate at different speeds.

But most of the time people mean the entire casing with ringgear and pinion included. Like the piece from an E36 BMW that falls down because the mountingpoints tear loose from the bottom of the car... ( happens with most E36 Beemers, the pins that hold the diff to the car just get torn out of the bottom. Only 3,2 M3 has this problem solved.A friend of mine had a diff hanging by the halfshafts after a day of drifting... )

[Zamani]

You mean just the planetary gears?

Anyway I'm looking for a suitable pump. Should it be diaphragm (hot oil and diaphargm....???) or gear pump?

[Mats]

Nah, you need the diff case to hold the pin, won't work without it.
Also, needs to be held together of course.

Same goes for a planetary or torsen type. Not working without the casing.

[kevin]

MD, still here. The oil discussion is fascinating. Just hope we can get to a conclusion. Going back to cooler, I found out that the four GTV 3.0l that race in our famous Kyalami 9hour never had oil coolers and there were never any crown and pinion failures. These cars did run full slicks. Nor were there any crown/pinion failures in that season. Im not sure what oil they were using either.
keep the discussion going.

[MD]

Here's a couple oil company replies. Puzzling to say the least.

Castrol initially recommends Syntrax 75W/90. This is contradicted by their own technical bulletins. A further review by the technical department subsequently affirms the use of this fluid as being appropriate. You work it out.

A response from Redline. Even worse. It is suggested to use and I quote "in your Alfa Romeo transmission I would recommend the 75W90NS and the 75W90 in the differential". Apparently not aware even after it was explained that the oil was intended for a 75 twin spark transaxle.

Understandably, I have written back to them for clarification.

So far 2 out of 2 oil companies = f*ck up.

On the plus side I am getting feed back that there are few racers here using Valvoline Duragear 75-W90 semi synthetic API GL5 and Redline Shockproof Light with success.

..stand by for more installments

[MR2 Zig]

Kevin,
Are you sure your transaxle is not somehow streched or deformed or not holding the propper ring and pinion clearance? Is this 2 failures in the same housing? Maybe that housing is no longer any good?

Just a thought,

[Mats]

MD, did you email the local sales rep? They are sales guys, they probably spent 2 seconds looking through a list and concluded that Alfas need this type of oil and then added some sales talk.

[MD]

Mats, let's get real here. I may be many things but I am no clairvoyant. When I email the contact details provided by the oil company I wouldn't know who the recipient will be. It is up to the company to sort out who is going to respond to an information request -technical or otherwise.

For all I know it's cleaner 'cause everybody else is out on lunch...there are responsibilities attached to advice. Just like on this site. You put your name to it, you wear it.

[Mats]

Yep, that's the way it is...

You need to filter the info and not trust everything blindly, healthy habit in all situations actually.

[kevin]

MR2 , these are two different housings. I have three boxes left so thats atleast 18months of racing. I have had my boxes assembled by different chaps including a mechanic from autodelta who ran the 33 racing team in the sixties. The trial will continue . Hopefully with corect oil - still waiting for outcome on this thread. If I win the lottery I will get a specially made box here by the chap who makes boxes for our F3000. He is a genius.
Note its only us chaps who are running 24v motors who are braking boxes. Not one failuer on 2.5 's and 3.0 12v. The 3.7 of Packers strips a pinion every three races.
Niclas car also has huge power, interesting how many races he has under the belt. Jes , how many laps have you done ?