Riding on Air

When the Visicoach rolled out of the Loudenville, Ohio factory, it was riding on four leaf springs. The leaf spring has been a part of vehicles almost as long as the wheel itself, having supported everything from horse drawn wagons to pony cars. Even modern Corvettes still use the technology.

But if you've ever ridden in the back of a school bus, you probably understand there is some potential for improvement on ye olde leaf spring. A modern air suspension can provide both a gentler ride down the road and significant improvements in handling.

The differences between metal springs and air springs boil down to a couple of key elements. Leaf springs create a mechanical connection between the chassis and the axle, providing a fantastic conduit for communicating every bump on the road right up into the passenger compartment. Air springs are more like heavy balloons, with a cushion of air that effectively separates the chassis from the axle and running gear.

And for the purposes of this comparison, leaf springs are essentially consistent in their spring rate, meaning that regardless of the movement of the bus or the wheels, the springs are going to give the same level of flex and resistance. Air springs, on the other hand, are dynamic. With valves, pressure regulators and a compressor, the rate of an air spring can change all the time.

Consider taking a fast corner in a tall vehicle like the bus equipped with leaf springs. Very quickly, a great deal of weight will shift to the outside of the turn and cause the bus to lean over to the outside, thrilling its occupants. In contrast, air suspension can automatically compensate as the weight shifts, increasing pressure on the outside air bags to keep the bus level through the corner. The bus is easier to drive and passengers have a more tranquil ride in the back.

That's a long way of saying we wanted to take advantage of the donor's air ride on the old bus. Simple in theory, challenging in practice.

First, the leaf springs and hangers had to come off the Flxible, along with all the running gear: wheels, axles, brakes and steering. We also had to flatten out the existing frame rails, which had arcs to provide space for up and down axle movement. The silver line that goes across horizontally is the seam where the existing frame has been extended with a new piece of steel to make it flat to support the geometry of the new air suspension.  You can also see the air bag installed on the trailing end of the link, just behind the blue and yellow of the new (old) shock absorber.

The new trailing link suspension mounts were cut to fit the Visicoach frame, then welded into place. Then we bolted the Freightliner trailing link arms into place to form the forward pivot for the suspension.  The air bags mount in back, along with a horizontal link that keeps the two sides in line. The scale of the Meritor rear-axle is still astounding to me.  There is just a lot of metal there. You can see the two air bags with the cross-link installed, looking through from the still-empty engine bay.

After the big metal work was complete, we installed leveling valves at each corner. With a simple linkage, the valves open or close depending on the movement of the axle relative to the chassis, regulating the air pressure at each corner.  The leveling valve is connected to the little arm in the top right of the photograph and then directly to the suspension link at the bottom. It is a remarkably simple technology that transforms the way the bus will handle on the road.  The last step is to install tanks to hold compressed air in reserve and keep the compressor from running all the time.

The bus requires a lot of plumbing, and the first components have been the air hoses. They'll supply both the suspension and eventually the brakes. With the axles mounted, we'll move onto the fitting and installation of the Cummins 5.9 turbodiesel and Allison transmission combination.

.andrew

The Donor

The 2000 Freightliner chassis lived out in the California desert under a tarp for about a dozen years.  I think it was originally purchased as surplus, along with half a dozen others, some of which were used for parade floats up the road at Disneyland.

Freightliner chassis in storage.

It was a dusty mess, but aside from that it had been well cared for -- run once a year or more to keep the parts from drying out.  With a fresh battery, the Cummins fired up almost instantly, spewing a great cloud of desert sand out of the radiator.  It tasted of dry.  Just dry. 

I'm told that the owner had occasionally taken his little fleet out for joyrides between the scrub brush and Joshua trees, packing a few pounds of landscape into the cooling system in the process.

In spite of the well aged diesel at the bottom of the tank, the engine tapped out a steady diesel rhythm; it turns out oil burning engines aren't quite as particular about their fuel as the average passenger car.  

As it chattered, the whole chassis lifted slowly onto the air suspension.  There is something eerie about a 30 foot vehicle frame, half-covered by old tarpaulins, seeming to levitate.  Still it was a good sign that all the key parts and systems were still operating properly.

Front sub-assembly
(note the steering wheel covered by a plastic bag)

Even on the high-desert back roads, the un-built chassis didn't qualify as street legal, so a crane and a piggyback trailer transported it back to the shop to be decomposed.

It is tough to convey the size of these parts in photos, but instead of the usual jacks and engine hoists you'd see in a hot rod shop, the chassis comes apart using a full sized fork lift and a crane truck.  Each subframe was unbolted, the engine and transmission removed, and the front and rear axles and their suspension components separated.  At the same time, the Flxible got propped on jack stands so its stock components could be cut away to make way for the new parts.

Front axle

At this point, the news is good on both chassis.  The Freightliner runs properly and all the components work as expected, with the exception of a cranky fuel pump.  The Flxible is coming apart easily and the underside hasn't provided any surprises.  With any 60-year-old vehicle, rust, old repairs and fatigue cracks are all potential problems.  So far, so good.
     

When Will it be Done?

I have a clear, rich vision for what the Visicoach will be when it is done.  Paint scheme, tail lights, upholstery, flooring...it is all in there.

And sometimes I look at the bus and just wish I could get in and drive it away.

But then I get caught up in something truly exciting.  Something like building a box out of aluminum diamond plate, fabricating a fan shroud or dismantling an old fuel system.  That's why I'm here.  Each corner of the bus has some new component to clean, repair, modify or protect.

"When will it be done" fades.

The bus was born in 1952 in Loudonville, Ohio and went into service on short-haul routes in New Mexico.  There's no way of telling how many miles it covered over the past 60 years, but it was designed and built for continuous service.

At the same time, modern components offer considerable benefit. Air ride is far more forgiving than leaf springs, power steering is...well...powered, and a contemporary turbo diesel delivers more power on less fuel.  So the plan is not just to restore the bus, but to modernize it.  A 1952 chassis on completely modern running gear.  Simple; not.

The best place to find all that running gear is another vehicle; a donor. In this case, we found a 2000 Freightliner motorhome chassis that had never been built into an RV.  It has a Cummins turbo diesel and a six speed, push-button automatic transmission.  It has a full air ride system, along with self-adjusting air brakes and power steering.  Air conditioning?  Yep, that too.

It is easy to look at the Freightliner chassis an think, "hmm, you could just cut the bottom off the bus and drop it right down on top.  Those big frame rails are designed to carry almost 10,000 lbs. more than the bus weighs with all its systems and powertrain in place."  That would be a nice idea, but alas everything from the wheelbase to the ride height is wrong.

Instead, we'll be dismantling both the bus and the donor chassis, replacing old with new.  Part by part, section by section, new components will get modified, cut, bent, and welded into place on the old bus.

Yes, it would be simpler to just go buy a spiffy new motorhome.  But then it would be done.

I do reserve the right to change my mind...

I Drove a Bus

The thing is, it is a five speed.  Manual.

I'm behind the wheel of a 35 foot transit bus on the outskirts of Apple Valley, Ca.  In the seat across from me is my new mechanic, whom I've only just met in person the day before.  A few minutes ago, we had the Flxible on a truck scale, (more on why, soon) where it weighed in at a bit under 17,000 pounds.

The original 1952

The extent of my bus driving experience has just passed the 65 mile mark, most of which I accomplished the day before on the ferry trip from the bus' previous resting place at a San Bernardino storage facility. My mechanic is every bit a heavy vehicle veteran and I am very much the eager hobbyist and all around amateur in the driver's seat.  That seat, as a matter of fact, is mounted on ancient springs that send me on a short space flight whenever we encounter a significant bump in the road.  

As a working bus, the Flxible was designed for easy commercial servicing. Its power train is mounted in a thick steel cradle that can be unbolted and slid out the back as a unit.  Mechanics could quickly swap the whole system, including both engine and transmission, to get a bus back into service. This particular '52 had a Ford truck motor installed at some point in its history. It is an enormous power plant: 534 cubic inches (almost 9 liters) and around 1,000 pounds. It is a slow-turner, too.  Unlike the engine in your car, which may spin at 6,000 rpm or more, the 534 tops out at about 3,400.  More importantly, it delivers its peak torque (what my Mom refers to a 'pickup') at about 1,800 rpm.  These engines were designed for moving heavy loads.  Going quickly wasn't really a priority.

Ford 534 V8 / Spicer 5-speed Manual in Cradle

The way back to the shop is down a wavy desert road.  The bus is relatively easy to drive on long stretches.  It tracks well on the road and the high seat position provides a great view out.  The one challenge--and it is a major one--is the five speed manual transmission.

In a car, a manual transmission is often located right between the driver and passenger--directly under the gear shift.  Even if the transmission is located elsewhere, the connection--the linkage between the shifter and the transmission--is no more than a foot or so.  In the bus, the gear shift is nearly 30 feet from the transmission.  The linkage is a series of loosely coupled metal tubes. Like a long distance phone call in 1952, the connection is persnickety.  

Torque is saving my bacon and protecting my ego as we proceed down the blacktop.  The gearshift in the bus is about four feet long, with a big round wooden handle on top that shines with 60 years of service.  The clutch, which feels like it is on the other side of the state, is a huge pedal poking almost straight up out of the floor.  It requires real effort to depress, and combined with the weary plates in the back of the bus, makes moving from gear to gear an awkward dance.  In fact, finding any one of the five forward gears includes a bit of effort, a bit of luck and frequently a bit of grinding. Thankfully, once engaged the big twisting power of the Ford is usually capable of keeping the bus moving.

Then we come to an intersection.  Specifically, it is a right turn onto the main road, midpoint on a hill. Hmmmm...

I have to slow down for the intersection, ensure I'm in the right gear to climb the hill, turn at slow speeds (no power steering, 17,000 pounds of bus), avoid the curb on the right, and keep enough momentum so I don't stall.

And the pro is in the passenger seat.

There was a lot of gear grinding, a few involuntary vocalizations and some deep grooves cut in the clutch at that intersection. With a little luck and momentum, I navigated the turn and got the bus onto Bear Valley Boulevard without incident.  And yes, I did check the mirrors for any aftermath or wake.

That was the last time I drove the bus.  March, 2013.

A Time Machine of My Own

Why a bus?

Why, indeed.

About five years ago, I became enamored with the compact RVs a number of companies built on 1-ton Toyota pickups in the late '80s. Those little trucks are legendary for their economy and reliability, and I liked the notion of room for four (maybe five) in a package that fits in a regular parking spot.

I found a reasonably healthy 1990 Sunrader, a 21-foot motorhome that I proceeded to restore and update in our driveway.  It has been finished at least twice so far, as we've gone back to replace cabinetry, counters and other fixtures.  I love the process of renovation.

I learned a ton but ultimately two things proved true. The Sunrader is just too small for any more than two people, especially if you're trying to have fun. And, however unique and wonderful the little Toyota may be, it will never have a place among the Airstreams and Microbuses that tell the story of the American road.

So I started looking at said Airstreams and other mid-century trailers for the next project. Chances are there is a Spartan, a Shasta or a vintage Airstream looking for some TLC just a Craigslist ad away.  There are also amazing restoration specialists like www.flytecamp.com who can merge era-correct looks with thoroughly modern systems and amenities.

Purely by accident, I came across a photograph of a Flxible bus conversion and I was instantly hooked. Its 50s streamline style is a tribute to the aesthetic of the time, from the front chrome to the functional tail scoop that drops into a tapered engine bay. Not only was a Flxible featured in the Kristin Chenoweth movie RV, the coach made an appearance as the team bus for the Brooklyn Dodgers in the film 42.

Flxible buses are relatively rare, and most of the remaining examples are either incredibly expensive or rusty skeletons.  Most often, they are someone else's project abandoned in progress. Finding a viable bus is tough, and prices understandably have more to do with the owner's personal passion for the vehicle than the real value.

Somehow, the '52 showed up on eBay at the same time I started seriously searching. Luck.  Minimal rust, roadworthy and with an existing (1975-era) motorhome conversion. I picked it up from the seller in San Bernardino and drove it all of 50 miles on my first day of ownership.  Now, almost a year later, it stands in a shop in Southern California -- on jack stands.  A work in progress.