LCGB Forums

Just a quick question. How's that Castrol Xl30 Classic Sae30? Is it any good for Lambretta?

I assume you're asking if you can use it as a transmission oil?

The answer is, yes! And, no!

Modern engine oils have detergents and special additives that clean out particles and hold them in suspension. If you have an old engine, it will have deposits inside. These deposits are stable and harmless. They can build up quite a bit over the years though. If you use a modern detergent oil, it will loosen these deposits and they will accelerate wear.

So, if you have an old engine with an unknown service history, stick with non-detergent 30 from a lawnmower shop.

If your engine is fresh, then it is fine to use a modern oil. Regular changes will keep things clean, no problem. However, technology has moved on. Myself, I use a GL-4 rated, automotive gear oil as it is much better for the high loads transmissions are subject to. Do not use a GL-5 rated oil as some of them are hard on brass bushings. Been using GL-4 gear oils for years in many different scooter transmissions with no issues. Gear oil viscosity is measured differently than engine oils. A 80/90 gear oil is roughly the same as a 30 engine oil.

jbcollier wrote:I assume you're asking if you can use it as a transmission oil?

The answer is, yes! And, no!

Modern engine oils have detergents and special additives that clean out particles and hold them in suspension. If you have an old engine, it will have deposits inside. These deposits are stable and harmless. They can build up quite a bit over the years though. If you use a modern detergent oil, it will loosen these deposits and they will accelerate wear.

So, if you have an old engine with an unknown service history, stick with non-detergent 30 from a lawnmower shop.

If your engine is fresh, then it is fine to use a modern oil. Regular changes will keep things clean, no problem. However, technology has moved on. Myself, I use a GL-4 rated, automotive gear oil as it is much better for the high loads transmissions are subject to. Do not use a GL-5 rated oil as some of them are hard on brass bushings. Been using GL-4 gear oils for years in many different scooter transmissions with no issues. Gear oil viscosity is measured differently than engine oils. A 80/90 gear oil is roughly the same as a 30 engine oil.

Great info JB. Thank you very much I will keep that in mind!

The original oils specified for the D/LD gearbox were monograde SAE 30 for summer and SAE 20 in winter conditions. I used multigrade 20w/50 engine oils in my LD gearbox without any problems, although there now are several straight SAE 30 gear oils available for classic car/bike gearboxes - by manufacturers such as Penrite. (I think straight 30 grade oil may be specified for V*spa gearboxes, although I'm not sufficiently interested to check it out... ) The high detergent multigrade oils are not required for D/LD gearbox use, more suitable for 4 stroke engine oil, where the oil is subjected to much higher temperatures and more combustion gases and particles find their way past the pistons!

Steve J wrote:The original oils specified for the D/LD gearbox were monograde SAE 30 for summer and SAE 20 in winter conditions. I used multigrade 20w/50 engine oils in my LD gearbox without any problems, although there now are several straight SAE 30 gear oils available for classic car/bike gearboxes - by manufacturers such as Penrite. (I think straight 30 grade oil may be specified for V*spa gearboxes, although I'm not sufficiently interested to check it out... ) The high detergent multigrade oils are not required for D/LD gearbox use, more suitable for 4 stroke engine oil, where the oil is subjected to much higher temperatures and more combustion gases and particles find their way past the pistons!

I see! Thank you Steve! Ill check good available options

ScooterRestorations sell "Rock Oil" Classic SAE30 for all 1950s Lambretta models D and LD - gear box only, at £7.95 for 1 litre.

Cambridge Lambretta sell "Putoline" SAE30 scooter gear oil for all Lambretta early models: A, B, C, LC, D, LD, E and F, at £4.99 (for 1/2 litre?)

Big Al wrote:ScooterRestorations sell "Rock Oil" Classic SAE30 for all 1950s Lambretta models D and LD - gear box only, at £7.95 for 1 litre.

Cambridge Lambretta sell "Putoline" SAE30 scooter gear oil for all Lambretta early models: A, B, C, LC, D, LD, E and F, at £4.99 (for 1/2 litre?)

Cheers Al!