Bus Stop Classics:  1966 to 1984 GM Denning Mono – King of the Outback 

Denning is one of the more storied of Australia’s coach and bus manufacturers.  Much like GM’s models in North America, they were the default image that many Australians had of an intercity bus – and still do to this day. 

1960 Denning body on Bedford J6 chassis

 

The Mono was one of Denning’s first rear-engined large coaches – and was developed as a domestic competitor to GM’s popular 4104 and 4106 which were imported by Ansett in limited numbers but would likely increase as trade restrictions were being lifted in the early 1960s.  Denning up to that point had been building coachwork that went over Bedford, AEC, Commer, and other OEM chassis.

GM 4107 Buffalo

 

Similar to what we saw in Brazil, given the popularity of GM’s coaches, Denning decided to “follow the leader” – in this case the soon to be introduced 4107 “Buffalo.”  In fact, Denning’s engineers visited GM in the US in the early/mid 60’s and saw the 4107 prototypes.  While GM didn’t participate in any of the design work for the Mono, Denning reached some form of agreement with the company to use their name in marketing it, likely in exchange for using GM’s engines as the sole powertrain option.  Thus the “GM Denning Mono” name.  Denning dropped the “GM” in 1976…perhaps the agreement expired, but many even today still refer to it as the GM Denning Mono.

1966 Denning Mono Squareline

 

The Mono’s appearance was very “Buffalo-like” – a “deck and a half” design with a lower driver’s cockpit and higher passenger area, maximizing underfloor storage. Aluminum fluting on the sides also mirrored North American buses.  Additionally, it had Denning’s first fully monocoque body, hence the “Mono” name.  The only major differences were Denning used much larger windows, and mounted the engine longitudinally rather than a transverse orientation.  The Mono went through many revisions and updates during its eighteen year model-life – the initial 1966 model was called the “Squareline”, and was 34 feet long, powered by a GM 6V53 engine with a Fuller 5-speed transmission.  

1968 model.  Note GM badging on front below windshield

 

1974 37 footer

 

Just two years later in 1968, a major refresh was launched with the new name “Classic.”  The GM Buffalo appearance was even more pronounced.  In 1971/72, longer 37 and 40 foot versions with a tag axle were added, and these came with DD 6 and 8V71 engines.  

In 1976 the bus was given a front-end revision with a forward leaning destination sign and a wrap-around grille.  Then in 1979, it would surrender its old leaf springs and get a full air-bag suspension, with the updated name “DenAir Mono”. Denning was worried about failures of the new air suspension over the tough Outback roads, so it conducted extensive and rigid testing in the remote wilderness before approving it for production.  

For its last several model years the newer 6V92TTA engine was added to the powertrain options, once again paired with a Fuller T905D 5-speed transmission, with an Allison HT-740 automatic optional. 

This beautifully restored DenAir is part of the Driver Bus Lines historical fleet – it is a 1983 model purchased new and was in service until 2008 – over twenty-five years!  More in the video below.

These Dennings had a reputation of being rugged, fast, reliable, well-built, and comfortable coaches.

The DenAir Mono was superseded by the Landseer, which we’ll review in an upcoming post.