ALFAGTV6.COM

[brookstroutr]

Hey, I just bought an '84 GTV6. What's the best fluid to use in the transaxle?[/list]

[Zamani]

Any 75w90 for non-limited slip should be ok (unless you have the 4.10 LSD setup). I'm using Mobil 1 75w90.

[JoeCab]

I've tried a number of lubes, including Mobil 1 and Red Line. They both work well, but sometimes seem a bit too slippery if your box has any wear at all to the synchros.

The lube I have found best is Ford 75W/140 Synthetic Rear Axle Lubricant. It's available at any US Ford dealer. I tried this on the recommedation of Rex Chalmers and was very happy.

Joe

[Zamani]

Joe,

IMHO, Mobil 1 is just OK. I wouldn't say it is super good or anything. I will try the oil you recommend. But isn't like $30/qt?

[P.Webb]

I use Amsoil Synthetic Gear Lube (LSD) in the Platinum box. So far, so good. Shifts nicely. A little stiff and notchy when cold. Smooth and positive when warmed up.

-Peter

[hutchensgd]

Do you guys mix synthetic and non-synthetic lubricatants? Or when you make the move to synthetic lubrication do you drain the transaxle?

[Alfa GTV6 NZ]

I was looking in the suggestion of Red Line oils.

Was loking at their website http://www.redlineoil.com/products_gear ... ubcatID=18

What would be better the MT90 or the 75W90 NS?

Both seem to be 75w90.

What have people tried?

[IndianaMark]

I have an 85 GTV6 with a rebuilt original transaxle with new syncros and bearings. I have been using Redline 75w90ns and it works just fine. The "ns" means no slippage modifiers have been added. According to the back of the bottle, this is the right formula for manual transaxles without Lim Slip.
The regular "75w90" has slip modifiers added for use with Lim Slip differentials to cut down on Lim Slip chatter. This oil is supposed to be slicker but would also cause the syncros to be less effective.
There is a school of thought that chooses to stay with factory spec "dino juice" based lube. The thinking says that since synthetic is slicker than conventional based lube, that the syncros will 'bite' better with conventional. The thinking does make a certain amount of sense for less than good syncros, but the improved qualities of synthetics should provide better overall protection for the transaxle. I would try the 70w90ns first. Anyway, that's my 2 cents. Maybe others can add opinions.

Mark

[MD]

For what its worth, I use Agip Rotra SX/S which is a 75W-90 synthetic compatible with limited slip diffs. Good gear selection when cold.

MD

[Mats]

Motul Gear 300. very nice.

[Que Boludo]

I just put an LSD(modified to 47%) in my 75,
and filled up with Castrol Syntrax 75-90, the shifts are much much smother hot or cold,
the diff has a bit of shutter on heavy acceleration in tight corners.

I also put new poly bushes in the watt’s links, it feels like a new car after all this work.

Much better then the Valvoline semi synthetic.

[MD]

Hey Que Boludo,

How do you find the 47% slippery around corners? Do you find that it pushes just a bit too hard in corners at the limit- particularly after the apex on the way out of the turn emphasising the understeer?

Would be interested in your opinion.

BTW, what size front & rear sway bars are you using? Thanks.

[Que Boludo]

I haven’t race the car yet, but I do race go-karts and yes it tends to push (understeer) into and out of the corner, just like the set-up in my kart I love slight understeer into a corner play with the throttle on the way out, it really jumps out of the corners.
Now in the rain..well just be careful, it does tend to be a bit snappy.

The car is a 75(originally 2.5L) with an internally modified 3.0L engine, suspension compromises of Koni yellow’s all round 30mm front sway standard torsion bars(next in mods) 105 castor mod, back springs are 15% stiffer with standard sway bar.
The new watt’s links poly bushes made a big difference in firming the back up.

I also have the Volvo 4spot’s and 164 rotors, this are a huge difference in stoping power.

Some photos of the engine build here.
http://www.alfabb.com/bb/forums/showthr ... #post70078