Oil for supercharger?

Oil for supercharger?

Question: "What oil should be filled in the supercharger?"

Peculiar but interesting subject... Indeed, the oil in the mechanical supercharger must be replaced periodically.

Only three classic Toyota engines were equipped with supercharger at factory:
- 4A-GZE (1.6) - for Corolla Levin/Sprinter Trueno 90-100, MR2 11
- 1G-GZE (2.0) - for Mark II/Chaser/Cresta 80, Crown 120-130
- 2TZ-FZE (2.4) - for Estima/Previa 10

Inline-6 was supplied to the domestic market only, the other two motors were overseas exported and became relatively known. It equipped with "Roots" type chargers SC-12 and SC-14.

Rem. Additional chargers as TRD, Blitz etc. tuning kits can be found on a wide range of Toyota engines at Japanese and American markets - but the question is not about them.

Manufacturer's prescription

Toyota officially prescribes to use special Toyota Supercharger Oil. It is filled in gear housing at the rear of the charger, the level is controlled by the dipstick. The capacity - about 130 ml.

Initially the oil with original part number 08885-80108 was offered. In reality, this number hides a kit of syringe, plastic hose and container with 50 ml oil (this volume would be enough just for top up).

Later Toyota offered the normal kit p/n 08885-09007, with 500 ml oil bottle. The basic cost is about $25-30 in Japan.

The another specific compound prescribed for the front bearing of the driven rotor - Toyota Supercharger Grease - p/n 08887-80109 (about 2 g required).

Reality

Unlike many other genuine goods, it is not possible to purchase these lubricants as usual. Not to mention the financial rationality.

All the world use traditional lithium grease for bearings instead Supercharger Grease (sometimes in excess quantity).

Transmission gear oil is used instead Supercharger Oil generally: it is enough for simple non-loaded gear drive.

Since the viscosity of the original oil is known - 63 cSt at 40°C / 13 cSt at 100°C, it is possible to find a substitution. Easy to notice, there is no need of too viscous gear oils (e.g. 75W-140 grade), neither too liquid motor oils.

The optimum is transmission gear oil GL-4 75W-90, with medium-to-low actual viscosity - 70-80 cSt at 40°C / 13-15 cSt at 100°C.