Nuss Collection Presents 1929 Mack AC

Hi, I’m Bob Nuss from the Nuss Collection Museum in Rochester, Minnesota. Today, I’d like to share a truly rare piece of trucking history: a 1929 Mack AC Tandem Axle Truck.
This truck is one of only 128 tandem axle configurations ever built by Mack, and today, approximately eight of these trucks remain. We’re proud to have this incredible piece in our collection.
This specific truck features:
• A 4-cylinder high-hat engine with removable cylinder heads, producing 75 horsepower.
• An engine with a 5-inch bore and 6-inch stroke, totaling 471 cubic inches-a big engine for its time!
Mack’s first attempt at a tandem axle chain-drive system, with two sets of chains and a drive shaft connecting the transmission to both axles.
A Mack winch on the back, powered by a PTO running from the transmission case to a jackshaft and chain system.
The engineering on this truck is extraordinary. The tandem axle system includes inverted springs, a design you’d expect to see on modern dump trucks but was ahead of its time in 1929. Mack’s innovation also extended to features like sealed spring ends to keep grease in and reduce noise-a small but impactful detail.
This truck was restored with the help of Tom Spencer, a longtime friend and one of the foremost experts on Mack AC restorations. His expertise brought this remarkable vehicle back to life.
We’re excited to have this one-of-a-kind tandem axle Mack AC on display at the Nuss Collection Museum. Come visit us and see this rare piece of trucking history for yourself!