Depending on the model series Stiebel gearboxes are delivered with or without oil filling. In any cases, it must be ensured that the lubricant is filled in the prescribed quantity before start-up. Quantity and quality of oil can be taken from the type label or the operating manuals. The oil quantity mentioned there could serve as a guideline.

Decisive is the marking of the oil dipstick, oil level glass or the overflow plug, as long as these are part of the equipment.

In cases of connections of e.g. pipes, hoses, pumps the oil level must be checked again after a certain switch-on time (e.g. 1h regarding to the operation manual) and, if necessary, filled up to the mark. The gearbox must not be operated without venting (filter or valve). Otherwise, an oil volume change can lead to leaks during heating or cooling.

The oil must be drained in an operating temperature to ensure complete oil replacement during the oil changing.

Recommendation:

If the oil is heavily contaminated, the gearbox should be rinsed with the new lubricant. At every change of oil, all seals and screw connections must be checked for leaks and tighten the screws if necessary. The magnet of cap screws with permanent magnet must be thoroughly cleaned. Generally Stiebel gearboxes can be operated with mineral oil CLP 220 according to DIN 51517-3. This quality is suitable for operating conditions with an ambient temperature of -10°C up to + 40°C. The choice of synthetic lubricating oils CLP HC (also called PAO, poly alpha olefins) results from the special operating conditions of the gearboxes, e.g. the ambient temperature. Significant hereby is the reached operation oil temperature.

Before using other oils, e.g. CLP-PG, food-compatible or biodegradable oils, please contact Stiebel.

To avoid overheating damage, dirt and dust deposits should be regularly removed from the gearbox surface. Additional oil cooling or heating systems can be provided in consultation with Stiebel.

 Oil Change intervals, permissible oil temperatures for mineral oil CLP:

 Oil Change intervals, permissible oil temperatures for synthetic oil:

The oil life time changes depending on the operating temperature.

As a rule the following assignment applies:
At operating temperatures > 60°C ► halved oil level per 10°C to 15°C rise in temperature.

Example:
Oil change interval P2000, mineral oil, operating temperature 95°C → 2000 h
Oil change interval P2000, mineral oil, operating temperature 80°C → 4000 h

The optimum time for the oil change can be determined by oil analyzes. For this purpose, an oil sample is taken, analyzed and evaluated by an authorized service provider (e.g. lubricant manufacturer). As a result the further use can be mentioned up to the due oil change or renewed oil sampling. Thus, a permanent monitoring of lubricant and gearbox conditions is possible.

Synthetic lubricants are not miscible with each other or with mineral oils. CLP HC oils (PAO = poly alpha olefins) are miscible with mineral oil residues. The possibility of oil miscibility can only be judged by the lubricant manufacturer. For the changing of lubricant type (CLP ↔ CLP PG, CLP HC ↔ CLP PG), the gearbox has to be flushed with the new lubricant before.

Rinsing process: Fill new oil up to specified oil level. Operate the gearbox for approx. 15 minutes without load, then drain the oil and fill in the new lubricant. Waste oil and flushing oil have to be disposed of in an environmentally acceptable manner.