How To Repair A Rusted Roof On A 1962 4106 Bus

(original pictures and some text past Paul N.)   Over the past several months, we've reviewed several different motor coach manufacturers that went toe-to-toe with Full general Motors in the intercity coach market place of the 1950's – ACF Brill, Brook, Fitzjohn, Aerocoach.  All fought the good fight, but concluded up on the canvas. OK, enough boxing metaphors – permit'southward look at the coach that vanquished all of these challengers, and prepare the template for all buses to come. All hail the GM PD 4104 Highway Traveler.

Paul'due south postal service on the 4104's predecessor, the GM 3751 and 4151 "Silversides" coaches detail how GM showtime became a powerhouse in the bus field, thanks to innovative alloy semi-monocoque construction and GM's new light but powerful ii-stroke diesel engine. That engine was so eminently well suited for buses with its transverse location at the very rear and angle drive to the rear wheels.

These and their predecessors were radically new before the war, and were given pocket-size updates when introduced in the post-war market place. They were first-class buses; well built and assisting to operate with the GM/DD half dozen-71 engine. Just they weren't the sweeping, all-new bus that Greyhound, GM'southward largest customer, desired for the mail-war era. It took a few more years for that model to be introduced – but when it was in 1953, it shook the intercity bus market to its cadre.

What fabricated the 4104 then special, and how did it come to utterly dominate the market? Several factors, merely first and foremost, it was merely patently superior to any other motorbus existence offered at the time. Permit'southward await at the details.

Weight. Rather than utilize a separate trunk and chassis, 4104's were fully monocoque-bodied (like to the Gar Wood coaches we looked at in our Aerocoach post). High strength aluminum panels over the monocoque frame made for an extremely low-cal yet rigid motorcoach, easily able to stand-upwardly to the constant over-the-road pounding an intercity bus endures.

Ability and mileage. The relatively light weight 2-stroke 210 hp Detroit Diesel fuel half dozen-71 engine, which was and then an sectional to GM coaches, combined with the calorie-free weight of the jitney, made the 4104 North America's most fuel efficient autobus, and almost likely one of its faster ones. A 4104 could typically get 8-ten miles per gallon of cheap diesel fuel compared to 2-3 mpg for the ACF Brill using the Hall-Scott gas engine, or 7-viii mpg for the Fitzjohn and Aerocoach which used the four stroke Cummins diesel. And it had a cruising/maximum speed of 65 mph.

The Rootes-blazon blower on the side of the engine is necessary for a ii-stroke diesel fuel to scavenge the cylinders apace besides equally fill up the cylinders with fresh air for the intake stroke.

A two stroke diesel operates rather differently than a gas-oil fed ii stroke engine, as the diesel fuel has two or four exhaust valves in the cylinder head. This shows its performance.

The Spicer unsynchronized four speed transmission transmission was also more efficient than afterward automatics, but it was non exactly "slick-shifting"

The long gear shift lever was some thirty feet abroad from the transmission, so it required a deft hand. Upshifts were relatively piece of cake, and the better drivers managed information technology without a clutch. Downshifts required double clutching and revving up the engine to the required speed in order to match the rotation speed of the gears on the output shaft. Pulling off a downshift without any hint of gear grinding was the sign of a superior commuter.

Ride. While other coaches were experimenting with air break systems, GM had theirs set up for use on both its urban transit and intercity models – it provided an extremely smooth ride, no thing how many passengers were on-lath, and just equally chiefly was very reliable.

These reinforced rubber bellow-type springs are utterly ubiquitous now on buses and a high percent of trucks and trailers, just in 1953, this was a big deal. The comeback in ride quality was very significant, equally steel-jump buses had to employ quite potent springs in order to cope with a full load. The air springs rode the same now matter how many  passengers.  I can remember riding on Marmon-Herrington trolley coaches in the early on '60s in my hometown of Columbus Ohio – these were steel leap buses and when lightly loaded, there was a cacophony of "Bam, Boom, Rattle" with lots of bouncing in the seats.

Storage. With no longitudinal frame, the 4104 had significantly more than underfloor storage capacity than whatsoever other motorbus – more room for luggage and freight, in those pre-FEDEX days.

Appearance. Though somewhat hard to envision now, the 4104 was a revolutionary design when launched – more modernistic looking than any other bus (or machine) on the road. It created every bit much buzz equally the '63 Stingray or ' 66 Toronado. The full aluminum-encapsulated body and forrad canted large windows became iconic pattern elements on buses for the next 30 years or more. Everyone rushed to imitate the 4104.

Quality. The folks who worked the line at the Pontiac Michigan Assembly Found knew how to build a bus. The key word here is "solid" – GM buses of the 1950's and 60'south had merely a much more solid feel to them than whatever other double-decker. I can remember riding Greyhound 4104s in the '60s and you could tell they had lots of miles on them. Withal, they withal had this "all-of-a-piece" feel.

It explains why the 4104s were nevertheless snapped upwards from Greyhound by smaller operators, and why they became the nigh favored bus for motorhome conversions for decades. They're however popular in that role, and it'southward relatively piece of cake to keep one on the road.

Put all this together and you get a coach that gave passengers a significantly elevated travel experience while at the same time put more than coin on operators balance sheets – a win-win…

Their durability and cost efficient attributes were not lost on operators outside Northward America either.

Testament to the goodness of their overall blueprint, the 4104 was superseded past the 4106 in 1961, which was essentially a 4104 with larger windows, an updated HVAC organisation, dual headlights, and the more than powerful 8V-71 engine.

And the 4104'due south avant-garde lightweight design, construction methods and even the slanted windows were all key aspects to GM's "New Look" transit buses in 1959.

The 4104 laso had a big brother, the iconic greyhound PD-4105 Scenicruiser. They were substantially co-adult, with the Scenicruiser arriving in 1954, one year after the 4104. Unfortunately, the Scenicruiser did not enjoy the same sterling reputation equally the 4104; it apace became rather problematic, with body peachy bug and issues with the twin engines. Paul'due south detailed write-upward is hither.

I routinely peruse various passenger vehicle and transportation websites and you find nothing but praise for the 4104; "the perfect bus", "the all-time charabanc ever congenital"…it still has lots of fans out there.

Over 5000 were congenital from 1953 to threescore – and their solid structure means many notwithstanding remain on the route today.

And some accept fifty-fifty been restored to their former all-original glory; now that'southward what I like to see.

Related:

1947 GM PD-3751 "Silversides": The Commencement Modernistic Passenger vehicle    PN

GMC "New Look" Transit Buses   PN

GMC PD-4105 Greyhound Scenicruiser   PN

How To Repair A Rusted Roof On A 1962 4106 Bus,

Source: https://www.curbsideclassic.com/bus-stop-classic/bus-stop-classics-gm-pd-4104-the-best-bus-ever-built/

Posted by: hardenbace1941.blogspot.com

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