OEX Alternator 12V 135A Delco 34SI Style DXA9123

The OEX Alternator DXA9123 is a new 12V, 135A alternator in 34SI style, made for Delco applications. It is a brushless unit with an internal regulator, and it uses a quad leg alternator mount with 198mm mount centre to centre and 101mm inside mounting legs.

For buyers comparing replacement units, the key identifiers here are the 12 volt system, 135 amp output, Delco suitment, Series 34SI, and part number DXA9123. The shaft diameter is 22mm, the adjusting hole diameter is 1/2 UNC, and the pivot hole diameter is 13mm, so matching the physical layout matters as much as matching the electrical rating.

This alternator is listed as new and weighs 12.42kg. OEX products are sourced from original equipment manufacturers and aftermarket suppliers, and the stated warranty is 3 years for passenger use and 1 year for commercial use. If you are replacing a truck alternator, checking the part number and mounting measurements before ordering is the safest approach.

Key Features

• 12V alternator with 135A output
• Delco 34SI style unit
• Brushless design
• Internal regulator
• New unit, not remanufactured
• Quad leg alternator mount

Specifications

• Brand: OEX
• Type: Alternator
• Voltage: 12V
• Power rating: 135A
• Series: 34SI
• Suits unit make: Delco
• Part No.: DXA9123
• New / Reman.: New

Known fitment applications

• Freightliner Century
• Freightliner Columbia
• Freightliner FL Series
• Freightliner FLB Series
• Freightliner FLC Series
• Sterling Trucks L-Line
• Western Star 4800
• Western Star 4900

Application and Buying Notes

Before ordering, compare the part number DXA9123 and the alternator layout against your original unit. The important match points here are 12V, 135A, Delco 34SI style, internal regulator, quad leg mount, 198mm mount centre to centre, and 101mm inside mounting legs.

The shaft diameter is 22mm, with a 1/2 UNC adjusting hole and a 13mm pivot hole. Those measurements help confirm whether the replacement will physically suit the bracket and adjustment arrangement on the vehicle, which is especially important on heavy-duty charging systems where mounting differences can stop a part from fitting correctly.

If you are replacing a failed alternator, it is worth checking the old unit for the same series reference and mounting pattern before you commit to the purchase. This alternator is a new OEX unit and weighs 12.42kg, so the physical size and bracket style should be verified alongside the electrical rating rather than relying on appearance alone.

The listed warranty is 3 years for passenger use and 1 year for commercial use. For truck applications, confirm the vehicle application, existing alternator label, and all bracket and terminal details to make sure the replacement matches the original installation requirements.

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 DXA9123 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 3yr Passenger 1yr Commercial, Inside Mounting Legs 101mm, Power Rating (Amp) 135, Series 34SI, Suits Unit Make Delco, Note Brushless unit, Mount Cnt to Cnt 198mm, Shaft Dimension 22.

Additional published details for cross-checking include Product Group 2 ALTERNATORS, Part No. DXA9123, Brand OEX, Description OEX Alternator 12V 135A Delco 34SI Style, Adjusting Hole Diameter 1/2 UNC, Pivot Hole Diameter 13, Regulator Type Internal, Shaft Diameter 22mm, Voltage 12.

OEX Alternator 12V 135A Delco 34SI Style. Part number DXA9123 should be checked first. Listed voltage is 12. Listed output rating is 135. These details form the core reference points used by parts interpreters when confirming the correct replacement.

Mount style is Quad 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 DXA9123, 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 135 should be checked carefully. Incorrect selection can affect installation time, return freight, and equipment availability.

Compatibility note: Confirm fitment using the part number DXA9123, the 12V 135A Delco 34SI style specification, and the mounting dimensions before ordering. If the original unit differs in mount style, shaft size, or regulator type, do not assume it will interchange.

FAQ

What vehicle applications are listed for this alternator?

The listed applications include Freightliner Century, Freightliner Columbia, Freightliner FL Series, Freightliner FLB Series, Freightliner FLC Series, Sterling Trucks L-Line, Western Star 4800, Western Star 4900, and Western Star 5800. For this listing, part number DXA9123 is the main reference point. Listed voltage is 12. Listed output rating is 135. Published fitment references include FREIGHTLINER CENTURY, FREIGHTLINER CENTURY 1988, FREIGHTLINER CENTURY 2000. These details should still be checked against the original unit before ordering.

What are the main electrical specifications?

This alternator is a 12V unit with a 135A power rating. For this listing, part number DXA9123 is the main reference point. Listed voltage is 12. Listed output rating is 135. Published fitment references include FREIGHTLINER CENTURY, FREIGHTLINER CENTURY 1988, FREIGHTLINER CENTURY 2000. These details should still be checked against the original unit before ordering.

Is this a new or remanufactured alternator?

It is listed as new. For this listing, part number DXA9123 is the main reference point. Listed voltage is 12. Listed output rating is 135. Published fitment references include FREIGHTLINER CENTURY, FREIGHTLINER CENTURY 1988, FREIGHTLINER CENTURY 2000. These details should still be checked against the original unit before ordering.

What type of regulator does it use?

It uses an internal regulator. For this listing, part number DXA9123 is the main reference point. Listed voltage is 12. Listed output rating is 135. Published fitment references include FREIGHTLINER CENTURY, FREIGHTLINER CENTURY 1988, FREIGHTLINER CENTURY 2000. These details should still be checked against the original unit before ordering.

What mounting dimensions should be checked?

The listed mounting details are 198mm mount centre to centre, 101mm inside mounting legs, quad leg alternator mount, 1/2 UNC adjusting hole diameter, 13mm pivot hole diameter, and a 22mm shaft diameter. For this listing, part number DXA9123 is the main reference point. Listed voltage is 12. Listed output rating is 135. Published fitment references include FREIGHTLINER CENTURY, FREIGHTLINER CENTURY 1988, FREIGHTLINER CENTURY 2000. These details should still be checked against the original unit before ordering.

What warranty is listed?

The warranty is 3 years for passenger use and 1 year for commercial use. For this listing, part number DXA9123 is the main reference point. Listed voltage is 12. Listed output rating is 135. Published fitment references include FREIGHTLINER CENTURY, FREIGHTLINER CENTURY 1988, FREIGHTLINER CENTURY 2000. These details should still be checked against the original unit before ordering.