High Output Alternators - EMP Power 450 3 inch, 4 inch, and ductless

High Stakes with High-output Alternators

High-output alternators are the heartbeat of large transit buses and motorcoaches. Beyond keeping the lights on and extending battery life, rider comfort and reliable performance are riding on high-output alternators. Economic pressures, supply chain roadblocks, and maintenance personnel shortages place maintenance managers in a high-stakes parts management conundrum.

The heavy workload of high-output alternators means they wear out quickly, performing for an average of only two years before needing replacement or preventative maintenance. When high-output alternators eventually fail, transit authorities and their maintenance crews need fast and effective solutions to get moving again.

The cost of buying a new high-output alternator ranges between $2000 to $5000. Repairing in-house is fast and cost-effective, but surface fixes can mean repeated downtime. Replacing an alternator with a repaired or remanufactured alternator from a third-party vendor also has its share of risks. 

Budget-conscious maintenance managers and purchasing agents don’t have to feel stuck with subpar options. Let’s look at the challenges facing transit professionals to better understand, evaluate, and manage the inventory of high-output alternators.

High Output Alternators - EMP Power 450 3 inch, 4 inch, and ductless

Comparing your options for replacing high-output alternators

Parts managers must evaluate cost, performance, and risks with new, repaired, or remanufactured high-output alternators to stock inventory at appropriate levels and maintain shop operations.

The upside and downside of buying new.

Buying new high-output alternators, such as the Niehoff C803D or the EMP Power 450, direct from the manufacturer can be a default option for maintenance managers. OEM parts promise hassle-free drop-in replacement. They may be under a warranty that can be claimed without too much trouble. (Check out our article on warranty scare tactics).

The downsides of buying new alternators.

New replacement parts are the most expensive option. While technicians can be confident that a new OEM replacement alternator will fit their application and perform appropriately, buying new can burden already strained budgets. When larger fleets replace hundreds or thousands of alternators every year, purchasing new replacements will stress a transit system’s operating budget. 

Beyond cost, the last few years have seen supply chain disruptions that increase shipping delays or even parts unavailability. Both mean longer downtimes. 

“Most manufacturers want us to stay there and wait for them, but we have to put coaches on the road,” he said. “There’s no doubt about it: The two major pain points for us are personnel and supply chain,”

–  Thomas Getachew, Fleet Services Manager, King County Metro, Seattle, Washington.1

Repairing High-output Alternators In-house:
Technical training gaps and personnel shortages have exacerbated the problem.

An apparent solution to supply chain disruptions and challenges in parts management would be to repair alternators in-house. Simple repairs that involve replacing bearings or seals—components that wear out quickly and are easy to exchange—make sense. Such repairs save money and get an inoperable bus moving again immediately. Often, these surface fixes do not address the root cause of failure and soon lead to another breakdown and more repair costs.

Personnel crunches and a lack of technical capability contribute to the difficulty of a sustainable in-house repair solution. 

Removing the gap in technical training.
For transit authorities equipped with rebuild shops, KIRKS Right Fit Kits provide all the components necessary for in-house remanufacturing. We extend support to technicians by providing onsite training and proprietary tools through KIRKS TOOLBox.

Shops across the country are equipped with KIRKS’ Transit-Tech 6000 to test in-house rebuilds for confidence that a high-output alternator will perform reliably after installation. Working with transit maintenance teams around the US, KIRKS makes onsite remanufacturing a viable choice for transit authorities.

Out-sourcing Remanufacturing of High-output Alternators

How can a third-party shop be trusted to remanufacture alternators you depend on?

Whether intentionally or mistakenly, shops can cut corners or skip an essential step in rebuilds. We’ve heard stories where “remanufactured” alternators arrive at transit garages and are non-functional out-of-the-box. They will not charge because they were insufficiently remanufactured and were not tested before shipping.

Properly remanufacturing a high-output alternator involves 

  • Complete disassembly
  • Cleaning, evaluating, and inspecting all components intended for reuse
  • Replacement of all critical wear parts 
  • Reassembly with approved used parts and supplemented with new parts 
  • Thorough performance testing under load 

A professionally remanufactured part in a process-driven remanufacturing operation will look and perform exactly like its OEM alternative. Choosing this option can save at least 50% of the cost of buying new while still providing confidence in direct drop-in and the performance of the alternator. So, how do you find a supplier consistently delivering “approved equal” quality?

KIRKS Reman Process for High-output Alternators

Since the first production of the Delco Remy 50DN in the 1970s, KIRKS has worked with the transit industry and alternator manufacturers to provide support for high-output alternators, including quality remanufacturing. Throughout the 70s and 80s, KIRKS was known as “The 50DN Guys” for our expertise and services for these alternators. (See 50 Years of High Output Alternators: What We’ve Learned)

KIRKS High-Output Alternator Remanufacturing Process

KIRKS provides components and remanufacturing options for high-output alternators, including the Delco Remy 50DN+; the Niehoff C703, C706, and C803D; and the EMP Power 450/Power 535. Our Approved EqualTM KIRKS Reman guarantees reliable performance and a perfect fit to get transit vehicles moving again.

KIRKS High-output Alternator Remanufacturing is outlined in 5 Steps:

Step 1: Disassembly and Cleaning
Our process begins with disassembly and cleaning. Alternators removed from the engine compartment are grimy, greasy, and many times locked up. We completely disassemble the unit and wash the components of all grease, oil, and dirt to evaluate each part.

Step 2: Inspection
The next critical step in our process is inspection. We thoroughly inspect each part – dimensionally and/or electrically. 

Mechanical components like casings and housings are dimensionally checked using micrometers and other tools, measuring bores and bearing surfaces to ensure they meet OEM specifications. 

We pay careful attention to the rotor, dimensionally measuring the outer and inner bell diameters, runout, bearing surfaces, and carefully inspecting splines and threads. 

The electrical components of an alternator also require inspection. The field coils and stators have insulation around magnet wire that must be inspected. The insulation in these components commonly degrades from exposure to oils and high temperatures. Using high-voltage testers, we ensure the insulation system is still robust enough to perform throughout an extended warranty period. 

Step 3: Replacement
All critical wear and rejected components from the inspection are replaced with those meeting OEM specifications.

Step 4: Assembly
Careful assembly includes a well-defined process with controls in place to ensure a quality remanufactured alternator.  Individual assembly steps are documented to ensure the right parts are selected, specific orders of operation are clear, and special characteristics like torque specifications are followed. 

Step 5: Testing
After final assembly and paint, the remanufactured alternator is tested using KIRKS Transit-Tech 6000 dynamometer—a proprietary test stand designed and manufactured by KIRKS.  It fully load tests the alternator while monitoring the current output, voltage, temperature, and oil pressure if applicable. The alternator is connected to a 50-horsepower motor that drives the alternator to up to 6000 RPMs. Adjustable load banks draw current to test under load up to 600 amps. 

Receiving our Seal of Approved EqualTM
Our Transit-Tech 6000 final performance test gives our customers complete confidence in every remanufactured alternator KIRKS ships. When we say it’s Approved Equal,TM that means it meets or exceeds OEM specs, will drop in, and reliably perform. 

KIRKS is the name for Remanufactured High-output Remanufactured Alternators

For the past 50 years of industry development of high-output alternators, KIRKS has developed unmatched experience and expertise. From the 1970’s “50DN Guys” to today, KIRKS supports all models of high-output alternators, including Delco Remy, C.E. Niehoff, and EMP models. For 75 years, KIRKS has collaborated with transit authorities and maintenance teams to provide dynamic and innovative solutions to every parts and service challenge. 

When alternator failures stall your operations, call KIRKS. Whether you are looking to source a new alternator, an Approved Equal remanufactured alternator, or a Right Fit Kit, you can be confident that KIRKS will meet your needs. 

In addition, KIRKS TOOLBox service provides onsite training for alternator preventative maintenance, remanufacturing, and testing.

For generations, our promise to you: We take the time to do it right – or better – the first time!
Visit us online to view our complete list of transit bus parts or contact us today to reach out to one of our product specialists. 


1 https://www.seattletimes.com/seattle-news/transportation/more-buses-idled-as-supply-chain-issues-hit-seattle-area-transit/