Which oil should you fill a geared motor with?

Choosing the right oil for a geared motor should be based on the manufacturer's data for the specific drive version. The oil type is marked on the gear unit's name plate (e.g. CLP PG 220), and this entry is the starting point for topping up or changing the lubricant.

To select a replacement (when you don't have an identical oil "to hand"), use the manufacturer's documentation – NORD manual B1000, point 7.2 describes lubricants and includes tables of oil and grease replacements.

NORD B1000 manual – Geared motors and gear units Tables of oil and grease replacements in chapter 7.2 · PDF, 3.9 MB, 80 pages Download the manual

The most important rules in practice:

• Do not mix oils of different bases and grades (if you are not sure, change over to a single, compliant type).
• Keep to the viscosity/grade from the name plate and the manufacturer's recommendations regarding quantity and service intervals (operating manual).

If you cannot read the markings on the name plate or have doubts about a replacement, SPEC SERWIS helps identify the correct oil and select an equivalent, supporting contact and technical arrangements with NORD.

What happens if you make a mistake?

In practice it ends in one of three scenarios: accelerated wear, overheating or seal damage. To be precise:

• Viscosity too low (oil too "thin") → a weaker lubricating film, metal-to-metal contact, rising temperature, noise, accelerated wear of gear wheels and bearings (seizure in the extreme case).
• Viscosity too high (oil too "thick") → greater resistance, a drop in efficiency, the drive heating up, starting problems at low temperature, under-lubrication at critical points (the oil doesn't reach where it should).
• Wrong base / incompatible type (e.g. mixing different oils or the wrong kind of synthetic) → additive conflict, foaming, deposits/sludge, poorer water separation, a sudden drop in lubricating properties.
• Incompatibility with seals → swelling or hardening of the elastomers, leaks, ingress of contaminants, falling oil level.
• Wrong additives (EP, anti-corrosion, anti-foam) for the given gear unit type → surface micro-damage (pitting), corrosion, shortened service life.
• "Business" consequences → often loss of warranty and more expensive servicing (because the cause lies on the operating side).

If you suspect the wrong oil has been poured in: do not continue operating under load! The safest solution is to contact us so we can carry out temperature and noise measurements and check for leaks. Based on such data, we are able to professionally drain all the oil, flush the housing and finally top up with the correct oil. In addition, we always carry out a condition check in which we focus on the magnetic plug and check for any swarf.