Bosch Alternator 12V 120A BXU12121A

The Bosch Alternator 12V 120A is a new rotating electrical unit supplied as each, with part number BXU12121A and a one year warranty. It is a 12 volt alternator rated at 120 amps, with an internal regulator and a single leg mount, so the key installation checks are voltage, output rating, mounting style, and shaft and hole dimensions before purchase.

This alternator is listed for Bosch units and is built as a new part rather than remanufactured. Important physical details include a 51mm mount leg thickness, 173mm mount centre to centre, a 10mm pivot hole diameter, M8x1.25 adjusting hole diameter, and a 17mm shaft diameter. Those measurements are the practical checks that help confirm whether the unit will line up with the existing brackets and drive arrangement.

The unit weighs 4.68kg and is described with corrosion resistant construction and a reduction drive. Those are useful details when the alternator is expected to work in harsh conditions or where stable starting characteristics matter. As with any replacement alternator, the safest approach is to match the part number BXU12121A and confirm the mounting and shaft measurements against the removed unit before ordering.

Key Features

• 12V alternator rated at 120A
• New unit, supplied each
• Internal regulator
• Single leg alternator mount
• Suits Bosch unit make
• Corrosion resistant construction

Specifications

• Part No.: BXU12121A
• Brand: Bosch
• Voltage: 12V
• Power rating: 120 amp
• Type: Alternator
• Unit of measure: Each
• New / Reman.: New
• Regulator type: Internal

Known fitment applications

• Allis Chalmers N5, N6, N7
• Case 590ST, 695ST, SR130, SR150, SR175, SV185
• John Deere 105, 2054, 2056, 2058, 2064, 2066, 4040, 4050, 4440, 4450, 4850, 544D, 640G III, 640H, 648H, 6605, 748G III
• New Holland TR86, TR87, TR88, TR89
• Same Falcon, Vigneron
• TVT155

Application and Buying Notes

Before ordering, check the part number BXU12121A first, then compare the alternator mounting setup on the vehicle or machine. The most useful dimensions here are the 51mm mount leg thickness, 173mm mount centre to centre, 10mm pivot hole diameter, M8x1.25 adjusting hole diameter, and 17mm shaft diameter. If any of those points differ from the removed unit, do not assume the alternator will interchange.

The 12V, 120A rating matters because alternators are chosen to suit the electrical system and charging demand already in the machine. This unit has an internal regulator, so it is intended for applications that match that regulator type rather than an external-regulated arrangement. Matching voltage and regulator style is just as important as matching the mounting pattern.

The listed fitment covers a range of Allis Chalmers, Case, John Deere, New Holland, Same, and TVT155 applications. Even where a model appears in the fitment list, it is still worth confirming the exact application, year, and any relevant build details. Alternators can vary within a model range, so the safest fit check is the removed part number plus the physical measurements.

This alternator is a new Bosch unit, not remanufactured, and it carries a one year warranty. The corrosion resistant construction and reduction drive are useful features where the unit is exposed to dust, moisture, or demanding operating conditions. If the existing alternator shows wear around the shaft, mounting ears, or pulley area, compare those areas carefully before choosing a replacement.

Before supply, the safest approach is to confirm the original unit details against the listed part number, voltage, output rating, mounting arrangement, and pulley configuration. That checking process is standard practice in the parts trade because visually similar units can still differ in service-critical ways.

For workshop, fleet, and equipment applications, accurate identification of part number BXU12121A helps avoid unnecessary freight, additional labour, and vehicle or machine downtime. Where the application is not straightforward, the original unit, OEM reference, or workshop records should be used as the primary confirmation point.

Relevant published details for this unit include Type ALTERNATOR, Unit of Measure EACH, Warranty One Year, Mount Leg Thickness 51mm, Pivot Hole Diameter 10, Regulator Type Internal, Suits Unit Make Bosch, Alternator Mount Single Leg, New / Reman. New, Weight 4.68kg.

Additional published details for cross-checking include Product Group 1 ROTATING ELECTRICAL, Part No. BXU12121A, Brand BOSCH, Description Bosch Alternator 12V 120A, Adjusting Hole Diameter M8x1.25, Pin Code IR200, Power Rating (Amp) 120, Shaft Diameter 17mm, Voltage 12, Mount Cnt to Cnt 173mm.

Bosch Alternator 12V 120A. Part number BXU12121A should be checked first. Listed voltage is 12. Listed output rating is 120. These details form the core reference points used by parts interpreters when confirming the correct replacement.

Mount style is Single Leg. Regulator type is Internal. Those physical and electrical details should line up with the original unit before the replacement is approved for fitment.

For part number BXU12121A, the normal identification sequence is part number, electrical rating, mounting arrangement, connector or terminal style, and pulley or drive details. Using those checkpoints helps confirm that the listed unit matches the service requirement rather than only looking similar.

For a alternator in workshop, fleet, trade, agricultural, or construction service, the listed voltage 12 and output 120 should be checked carefully. Incorrect selection can affect installation time, return freight, and equipment availability.

Available application references include ALLIS CHALMERS N5, ALLIS CHALMERS N6, ALLIS CHALMERS N7, CASE 590ST, CASE 590ST 2015, CASE 695ST. Even with application listings, final confirmation should still be based on the exact unit being replaced and the service requirements of the vehicle or machine.

Compatibility note: Confirm fitment by matching part number BXU12121A and checking voltage, regulator type, single leg mounting, shaft diameter, and the listed hole and centre-to-centre measurements against the removed unit.

FAQ

What voltage is this Bosch alternator?

It is a 12V alternator.

What is the output rating?

The alternator is rated at 120 amp.

Is this a new or remanufactured unit?

It is listed as a new alternator.

Does it use an internal regulator?

Yes, the regulator type is internal.

What is the part number?

The part number is BXU12121A.

What should I check before buying?

Check the part number, 12V system requirement, internal regulator type, single leg mount, and the listed measurements: 51mm mount leg thickness, 173mm mount centre to centre, 10mm pivot hole diameter, M8x1.25 adjusting hole diameter, and 17mm shaft diameter.