Gear oil

[lancialulu]

Any thoughts on EP (or not) 140 gear oil for diff and steering box on Aprilia??? Looking at the Miller site it offers a Non EP 140 for classic cars?

Tim

[Sliding Pillar]

On my Aprilia I used Penrite oils,  Mild EP for the back axle, Transoil 140 for the gearbox and their Steering box lube which is nice and thick so doesn't leak out!

[ColinMarr]

I think EP (Extreme Pressure) oils contain an additive that does nasty things to brass. The Aurelia gearbox has lots of brass/ bronze in the synchromesh parts and so EP was not advised. Although the Aprilia has no synchro there may be other brass parts, so maybe best avoided.

Colin

[johnturner]

I was told by a nice man at Shell that modern EP oils have been modified so that they no longer attack bronze, but I'm not sure I trust him, so I use straight oils in the Lambda and the Augusta, from Morris of Shrewsbury who seem generally cheaper than Castrol/Penrite.  Also to avoid using up the very little horsepower produced I use 30 grade in the gearbox and 90 in the back axle.  I have had 30 grade in the Lambda gearbox for the past 40 odd years without any obvious ill effect.

John

[JohnMillham]

I was told by a nice man at Shell that modern EP oils have been modified so that they no longer attack bronze, but I'm not sure I trust him, so I use straight oils in the Lambda and the Augusta, from Morris of Shrewsbury who seem generally cheaper than Castrol/Penrite.  Also to avoid using up the very little horsepower produced I use 30 grade in the gearbox and 90 in the back axle.  I have had 30 grade in the Lambda gearbox for the past 40 odd years without any obvious ill effect.

John

I use thin oil in the gearbox, too, as I'm convinced it gets to parts the thicker oil can't reach. So far, I haven't noticed any ill effects and I'll bet the little spigot bearings are still in good condition.
Regards, John

[Scarpia]

I have had 30 grade in the Lambda gearbox for the past 40 odd years without any obvious ill effect.

the oil might be due for a change then.... exceeding your service intervals like this may also invalidate the manufacturers warranty...

[davidwheeler]

Definitely no brass in an Aprilia gearbox (How many times have I stripped the d...d thing?).  Don't know offhand about the rear drive.  I have been putting EP80 in the box but I use 10/40 in the Lambdas and I think it speeds up the change so I will probably do the same with the Aprilia.  Steering box (also no brass) is currently retaining its EP 90 since I fitted new seals but I rather like the idea of using Moly grease as I do in the Lambdas.

[BlueSky]

I've been using Penrite Sin Gear Oil 75 in the gearbox and differential for the last four years. When I got the car finding 2nd was always a problem but changing to the Sin75 solved that issue. Also use Penrite steering box lube to stop the leaks! The sump plugs in the gearbox and diff are brass, but that's all.
Noel

[davidwheeler]

I've noticed, since my latest gearbox rebuild (!) that third gear did no go in properly when the box was cold but was fine once it warmed up.  I have just drained it and put in 10/40.  Watch this space...

[JohnMillham]

And another thing! I found the Aussies are quite correct when they warned me not to fill my (Lambda) gearbox up as far as the recommended level. Leaving it a bit lower allows the oil to be thrown up to the gear-change mechanism by the exposed gears, which is otherwise without lubrication. When the level is as recommended by Lancia, the gears are submerged and just stir the oil around without significantly throwing it upwards. Since doing so, the gear change is improved.  Regards, John

[davidwheeler]

10/40 seems to work beautifully, the gears go in and stay in and they are as silent as before with heavy oil.   Many years ago, in that seminal tome "The Restoration, Maintenance and Driving of Vintage Cars" (which I cannot now find on Google) I read that, as the Mini had demonstrated the use of a modern engine oil in the gearbox, the same could be done in a Vintage car with no increase in wear and a notable increase in the speed of the gear change.  For many years I used engine oil in Old Boot's gearbox but for some reason started to use thick stuff again a few years back.  Perhaps if I go back to engine oil, she will stop falling out of third gear as well...

[davidwheeler]

Hmmm, I spoke too soon, still reluctant for the first few miles but better than it was...