CORTECO 12011127 NBR BASL 26x37x7 Radial Shaft Seal

Technical specifications

OE cross-reference numbers

The following original equipment references are associated with CORTECO 12011127 in replacement-parts catalogues.

These references support component identification but do not establish compatibility with every gearbox or vehicle manufactured by the listed brands.

The exact application should be verified using the original equipment documentation, gearbox identification and relevant assembly information.

CORTECO 12011127 – catalogue identification

The CORTECO dimensional catalogue identifies 12011127 – NBR BASL – 26x37x7 mm, with MERCEDES TR (Mercedes Trucks) indicated as an application.

Replacement-parts catalogues also identify the reference 12011127B, while 82011127 appears as an additional commercial designation.

Catalogue information confirms that the 12011127B version incorporates an additional dust lip.

The OE references CARRARO 025539 and MERCEDES-BENZ 0029973846, 0039979946 and 0109977346 are listed in aftermarket cross-reference catalogues.

When ordering, the complete manufacturer reference, dimensions, material and sealing profile should be verified.

What does CORTECO 12011127 NBR BASL 26x37x7 mean?

The designation identifies the manufacturer, catalogue reference, dimensions, elastomer material and sealing profile.

• CORTECO – manufacturer brand.

• 12011127 – product catalogue reference.

• 26 mm – nominal shaft diameter.

• 37 mm – nominal housing bore diameter.

• 7 mm – nominal axial width.

• NBR – nitrile butadiene rubber.

• BASL – radial shaft seal profile with a rubber-covered outer diameter, spring-loaded primary sealing lip and additional dust lip.

The BASL designation is particularly important when replacing an existing seal because the additional dust lip distinguishes it from the standard BA profile.

BASL sealing profile – construction and operating principle

The BASL profile combines lubricant retention with additional protection against external contamination.

Its construction includes four principal elements.

1. Rubber-covered outer diameter

The elastomeric outer surface helps provide a secure seal between the component and the housing bore.

It can accommodate minor housing surface irregularities within the manufacturer's permissible tolerances.

2. Internal metal reinforcement

The metal reinforcing insert provides dimensional stability and helps maintain the shape of the seal during installation and operation.

3. Spring-loaded primary sealing lip

The primary sealing lip maintains contact with the rotating shaft surface.

A garter spring helps maintain the required radial contact force, supporting lubricant retention during gearbox operation.

4. Additional dust lip

The secondary dust lip provides an additional barrier against external contamination, including dust and fine particles.

This feature can be particularly useful in mechanical assemblies exposed to environmental contamination.

However, the presence of a dust lip does not mean that the seal is designed for continuous immersion in water or high external pressure.

NBR material properties

NBR is a synthetic elastomer produced from acrylonitrile and butadiene.

It is widely used in gearbox and radial shaft sealing applications because of its compatibility with many mineral oil-based lubricants.

Typical characteristics of appropriately selected NBR compounds include:

• Good resistance to many mineral oils.

• Compatibility with numerous industrial lubricating greases.

• Suitable mechanical properties under appropriate operating conditions.

• Resistance to wear under correctly lubricated operating conditions.

• Application in mechanical transmissions and rotating shaft assemblies.

NBR is not universally resistant to all fuels, solvents or industrial chemicals.

Its resistance to ozone and certain atmospheric influences is limited.

The exact operating temperature range and compatibility with a particular gearbox oil depend on the specific elastomer compound.

BASL versus BA – sealing profile comparison

A BASL seal should not automatically be replaced with a BA seal, even when the nominal dimensions are identical.

The additional dust lip may be necessary to meet the contamination protection requirements of the original application.

Selection and interchangeability

Before selecting CORTECO 12011127, verify:

1. Nominal shaft diameter – 26 mm.

2. Nominal housing bore diameter – 37 mm.

3. Installation width – 7 mm.

4. Required BASL sealing profile.

5. Presence of an additional dust lip.

6. Compatibility of NBR with the gearbox lubricant.

7. Shaft surface condition and housing bore tolerances.

8. Operating temperature, pressure and shaft speed.

9. Original equipment reference.

10. Specific gearbox or mechanical assembly identification.

Matching dimensions alone do not guarantee interchangeability.

The replacement must also provide the required sealing profile, elastomer compatibility and operating characteristics.

Applications – CARRARO and MERCEDES-BENZ

Replacement-parts catalogues identify CORTECO 12011127B as a radial shaft seal used in manual gearbox shaft applications.

The listed OE references associate the product with CARRARO and MERCEDES-BENZ components.

Depending on the original equipment configuration, the seal may be used in:

• Manual transmission shaft assemblies.

• Gearbox input or output shaft sealing positions, where confirmed by equipment documentation.

• Commercial vehicle transmission systems.

• Mechanical drive assemblies.

• Gearboxes requiring additional protection against external dust.

These are potential application areas rather than verified fitment information for individual vehicles or gearbox models.

The original equipment reference must be checked against the specific mechanical assembly.

Alternative designations and cross-references

Common English technical designations include:

• CORTECO 12011127

• CORTECO 12011127B

• CORTECO 82011127

• CORTECO 12011127 NBR BASL

• CORTECO 26x37x7 NBR BASL Oil Seal

• CORTECO 12011127 Radial Shaft Seal

• CORTECO 26x37x7 Gearbox Oil Seal

• Radial Shaft Seal 26x37x7 NBR BASL

• Gearbox Shaft Seal 26x37x7 with Dust Lip

Replacement-parts catalogues also list the following comparison references:

These references require verification against the exact replacement component before substitution.

Installation and operating recommendations

Before installation, clean the housing bore and inspect the shaft surface for scratches, corrosion, burrs and excessive wear.

The seal should be installed evenly using suitable mounting tools.

Installation force should be applied to the appropriate structural area of the seal, avoiding direct pressure on the sealing lips.

In conventional applications, the spring-loaded primary sealing lip faces the medium being retained unless the equipment documentation specifies otherwise.

Appropriate lubrication should be provided at the sealing contact area before operation.

The additional dust lip must also be installed and lubricated, where required, according to the manufacturer's instructions.

Incorrect installation, excessive shaft runout, inadequate lubrication or unsuitable surface roughness may result in premature wear and lubricant leakage.

FAQ – Frequently asked questions

1. What are the dimensions of CORTECO 12011127?

The nominal shaft diameter is 26 mm, the housing bore diameter is 37 mm, and the axial width is 7 mm.

2. What does the BASL sealing profile mean?

BASL identifies a radial shaft seal with a rubber-covered outer diameter, spring-loaded primary sealing lip and additional dust lip.

3. Does CORTECO 12011127 have an additional dust lip?

Yes. The additional dust lip is a confirmed feature of the CORTECO 12011127B version.

4. Is CORTECO 12011127 suitable for gearbox applications?

Replacement-parts catalogues describe the product as a manual gearbox shaft seal. Compatibility with a particular gearbox must be confirmed using the OE reference.

5. Are CORTECO 12011127 and 12011127B the same product?

The dimensional catalogue identifies 12011127, while replacement-parts catalogues use 12011127B for the NBR BASL 26x37x7 mm version. The current manufacturer designation should be verified before ordering.

6. What MERCEDES-BENZ OE references correspond to this seal?

The listed references are 0029973846, 0039979946 and 0109977346.

7. Is CARRARO 025539 a cross-reference for CORTECO 12011127?

Yes. CARRARO 025539 appears in replacement-parts cross-reference catalogues.

8. Can a BA seal replace the BASL profile?

Not automatically. BASL incorporates an additional dust lip, so the replacement must meet the original application's sealing and contamination protection requirements.

CORTECO 12011127 – key information

CORTECO 12011127 / 12011127B is an NBR radial shaft seal with nominal dimensions of 26x37x7 mm and a BASL profile. Its construction includes a spring-loaded primary sealing lip and an additional dust lip. Replacement-parts catalogues associate the product with CARRARO 025539 and MERCEDES-BENZ 0029973846, 0039979946 and 0109977346. Correct selection requires verification of the gearbox assembly, lubricant compatibility and complete sealing profile.

The product is offered through the specialist B2B industrial trading platform simmering.pl, serving industrial companies, technical purchasing departments and maintenance operations, with worldwide shipping from stock in Poland.