What Are Hollander Numbers?by Mateo Zeske
Hollander numbers describe a system used by the Hollander Interchange Manual that links vehicle part numbers with vehicle parts that are interchangeable. Car enthusiasts use a Hollander manual to look up a part number and car they are working on to find parts that will perform the same function when replaced or modified. The numbers lead to a variety of parts options, often to find cheaper solutions, and also are used to sell parts online and for inventory at auto salvage yards.
The reference numbers are named after the company's founders, Hildur and Roy Hollander, two brothers who formed the company after a brief career as a musical duo. "Automobile manufacturers were reluctant to admit that some of their parts would work equally well in other models. Hollander persisted, and in 1934 published the first edition of the Hollander Interchange Manual," according to the company's website. The manual now has become an industry standard and is used by 2,500 salvage yard management companies in North America alone.
The manual's listings cover the past 70 years as of 2011. The manuals cover most foreign and domestic cars and light trucks and more than 150 parts and assemblies, according to the website. The manuals can be shipped by mail or downloaded as the Hollander Electric Book for a fee.
How to Use
The manual lists a part number (such as part 103) or part name in its Table of Contents. The corresponding part number page listing tells what part of the car the part goes to, such as "Door Assembly, Rear or Back." The next step is looking up the vehicle's manufacturer in the Index, which is organized by manufacturer, make and year. The manufacturer page breaks down vehicles from one company by model and year and divides model year listings by electric and manual versions, with a Hollander Interchange number for each appearing in the Interchange column.
The rest of the Interchange column is devoted to listing a vehicle's manufacturer and make and model types with interchangeable parts for the vehicle you are researching. This column lists vehicle details at the left and an estimated price in U.S. currency for the part at the right.
Alpha Extension Numbers
Hollander numbers also include Hollander Alpha Extension numbers. These reference parts of vehicles that would be interchangeable with minor modifications. Notes accompany Hollander Alpha Extension numbers to guide the reader on how to modify them, such as "A and B interchange; difference is regulator," "electric only," and "automatic door-lock control system standard equipment."
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