The Crown Advisor

Thinking about buying a Crown Coach?

Here is the text of many of the e-mails I have sent out regarding Crowns. This information is by no means complete, but it does represent the bulk of my first-hand knowledge about Crown Coaches.

Bus Types

Crown Corporation was in the business of building bus bodies from 1904 until 1991. During that time, a huge variety of body styles were manufactured. By far, the most common and familiar are the classic 'Super Coach' design buses, which are in school bus fleet service all over the country.

Included in the list of other body types are the Security Coach (prison bus), specialty type buses, which were hybrid freight/passanger buses, and Atomic Coaches, made for the Department of Energy. Additionally, Crown manufactured Firecoach fire engines, as well as other fire apparatus bodies, which were mounted on various other maker's chassis.

Crown also made transit and intercity buses, so it is always possible to run into a bus that doesn't conform to the specifications on this page. I know that Crown did manufacture some rear-engine models.

Engines

Engines used in relatively 'modern' coaches are of only a few types. Early coaches used a Hall-Scott underfloor gasoline straight six. I know very little about this engine except that they were also used in some fire engines, got only about 2 miles per gallon, and are impossible to get parts for these days.

The most common engine is the Cummins 220, which is a six cylinder, 746 cubic-inch diesel engine developing 220 horsepower. One factory option was to put a turbo on a Cummins 220 engine, which boosted the output to 262 horsepower. These engines are very well regarded by truckers, powerful, long lasting, and easy to get parts for. Many school districts bought 220's and later upgraded them to 262's with the addition of a turbo and lower compression pistons.

Never run one of these engines out of fuel !!!!!!! At the least, you'll be stuck alongside the road waiting for a diesel service company to re-prime your entire fuel system. At worst, the engine will suck crankcase oil past the piston rings, begin to speed up RPM's, fail to stop when you try to shut it down and eventually explode spectacularly in a huge pile of oily wreckage.

The engine is mounted mid-ships below the frame, laying on it's left side, with the injectors and intake ports facing down. The crankshaft is centered in the frame rails, (below the frame, of course). The heads and valve covers, intake and exhaust manifold, and turbo occupy the area to the left of the frame. Power steering pump, alternator and air compressor are on the right, along with the oil filter can, fuel filter, engine batteries and starter. Originally, this bus must have had a 24 volt starter, but the series/parallel switch was removed, and it is now a straight 12 volt system. The starter still says 24 volts on the name plate ( ? ), but it starts fine on one battery. The mounts are three, two to the frame from the bell housing, and one in the center at the front to a cross member.

The radiator is located behind the left front wheel, flat against the side of the bus below the floor (see the 'before' photo of my bus, behind that grille). A shroud conducts air from the back of the radiator, to the fan, which is mounted at the left front corner of the engine. My bus came out of the Mohave desert, where it must have operated in extreme heat. If it was a problem, the 20 pages of maintenance records I got with the bus don't mention it.

Most recent Crowns have Detroit Diesel engines, as do the few rear engine models.

Transmissions

I know of only a few transmission configurations. My bus has a Spicer 5-speed manual.

Newer coaches sometimes have an Allison Automatic.

By far, the most interesting and coveted is the Eaton Road Ranger 10 speed. I met a local guy who worked for a bus dealer in LA, working on and delivering Crowns in the 70's. He said that buses with the Road Ranger would leave all other buses in the dust, arriving an hour before other buses in a delivery caravan after climbing long passes.

Axles, Tires, Driveshaft, Steering

Suspension is standard leaf springs, probably the progressive variety. Shocks are whopping-big car-type units. A trucker who I showed it to said that the rear suspension was identical to a Mack in configuration. This may not be stock, as there is evidence of modification in the rear frame area.

Some 'tandem' Crowns actually use a tag axle, which is mounted in front of the drive axle.

The indentification plate on the dashboard of my bus indicates that it was originally equipped with 11.00 x 20 tires. At some point, the school district changed over to 12R22.5 rubber, which are tubless radial-ply tires. Tube-type truck tires are becomming less and less available, so anything goes in this department.

My driveshaft is a single unit, about two feet long, with a slip at the transmission end. A second driveshaft connects the #2 rear axle driveline input yoke through a differential in the #1 rear axle.

My bus has 'Ross' power steering. Don't know if they all do, but Wow, what a lot of work it would be to steer if they didn't!

Brakes

All of the Crowns I have seen had air brakes. Mine have been modernized, with new control valves, modulator pedal assembly, and wheel units installed. The manual parking brake assembly was removed, leaving the disc on the rear of the trans. This is probably to satisfy some school bus regulation about being able to leave the driver's seat after losing a driveshaft. There is a parking brake actuator valve on the dash which engages the air brake units on both rear axles.

Body

The basic body style of Crown Coaches has not changed since the 1940's. Only small cosmetic varations differentiate early Crowns from their latest counterparts.

Early Coaches have short windshields, which are about the same height as the side passanger windows.

Curved windshield glass was optional, specified at the time of ordering the bus.

Several different styles of 'beltline' side moulding were manufactured, with differing width stripes, and courrigations.

Late model Crown Coaches have the tail lamps mounted in the far outside curved body panels, while earlier buses have the lights mounted in the rear trunk doors.

Construction is welded steel 'hat channel' framework with aluminum body panels, riveted in place.

I don't know if this is a common problem with Crown buses, but there was substantial metal fatigue at the level of the bottom of the windows, particularly on the right side. In fact, there were only two out of 11 posts that were still connected on the right, the first and last. When I stripped off the windows and interior sheathing, I could see that repairs had been attempted, riveting, welding, additional pieces of 1" 12 gauge box tubing, the whole lot. This is why I decided to just cut it all off at floor level and start over from scratch. This explained why the school district sold this particular bus with a fresh engine rebuild and all of the other upkeep it had. It had a broken body, although it was mechanically sound.

My bus did log 609,000 miles on unpaved, washboard-rough desert roads, so some metal fatigue is to be expected.

If you are going to work on a Crown, you need a special set of "Gulmite" tools to drive the "Crown Head" screws that hold most of the sheet metal and trim together. These screws have 24 little points around the head, and NOTHING ELSE but a Crown Head tool will work on them, except vise-grip pliers, and then not very well. I bought a set, which is a #6, #8, #10, #12, & ½" for $78.00 from the local fastener supply house. They had to special order them from L.A. I suggest that you find a set and purchase them ASAP, as they will save you hours of frustration and wrecked projects. This assumes that your bus used them in it's construction. They are quite good quality, and I have been putting them back into my new construction when I can, as I have thousands.

Price

As far as value is concerned, I have seen an 1958 35' sell for $3800, a 1962 35' for $4200, a 1957 40' for $7500, a 35' foot, 262 HP for $4,000.and I paid $6750 for my 40'. They seem to hold their value well over the years. Buskid bought her 40' tandem dual bus for $2,500.