San Francisco's Vintage Buses

No.4154

AM General Diesel Coach

Built 1975 • Operational

The GM “Fishbowl” buses Muni bought in 1969 and 1970 did the job all right, but their loud V8 engines and even louder “Jake brakes”, which sounded like machine guns when applied downhill, ticked off people along their routes, especially in quieter residential areas. So, Muni decided to finish replacing its venerable fleet of Macks with a smaller, quieter bus.

They chose AM General’s Model 9635, a 35-foot coach powered by a V6 engine, and took delivery of 100 of them in 1975. These buses were the first delivered in Walter Landor‘s striking design of white, “California Poppy Gold” (yellow-orange) and “Sunset Glow” (red orange). They also were the first bus delivery to wear the Landor-designed Muni “worm” logo, still in use today.

AM General was formed when struggling automaker American Motors purchased the Jeep Corporation from Kaiser in 1970. Thus, this bus has family ties to both the iconic jeeps of World War II and the Hummer, which AM General later built. Seeking new business lines, AM General licensed a bus design from Flyer Industries of Canada and made small modifications, which is why the coach looks a lot like the Flyer trolley coaches Muni was acquiring at that same time. AM General built more than 5,000 motor coaches and more than 200 trolley coaches between 1974 and 1979, then exited the business.

AM General Diesel Coach
AM General Motor Coach 4154 and 1938 White Motor Coach 042 in front of the historic Audiffred Building on Mission Street during Muni Heritage Weekend 2014. Peter Ehrlich photo

Officially dubbed “Metropolitans” by AM General, this model coach instead gained the nickname “Gremlins” at Muni, after a small automobile made by American Motors at that time. Alternatively, they were called “Amys”, a play on their manufacturer’s initials, in the same way that the GM buses were called “Jimmys”.

These 40-seat buses were largely used on lines with lower ridership and those on narrower residential streets. This particular coach, 4154, and one other in the class (4190) were repowered in 1984 with a Detroit Diesel 6V92TA engine and an Allison VS2-8 transmission. All 98 other buses in the class retained their original Detroit Diesel 6V71N engines and Allison VH9 transmissions. 4154 and 4190 were repowered in 1984. The last AM General buses were retired from regular service in 1991.

Coach 4154 has operated in several Muni Heritage Weekends and remains operational.

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Originally built for
San Francisco Municipal Railway, 1975

Builder
AM General Corporation, South Bend, Indiana (Model 9635)

Length
35'

Width
8'0"

Seats
40 (originally 41)

Motors
Detroit Diesel 6V92TA (from 1984); Detroit Diesel 6V71N (as delivered)

Controls
Allison VS2-8 transmission (from 1984); Allison VH9 (as delivered)