TR4

The body is what first distinguishes the TR4 from the earlier Triumph models (later TR bodies, through the TR6 , would continue to contain many aspects of Michelotti’s TR4 design). By the late ’50’s the idea of an open cockpit, low door, side curtained roadster was seen as out-dated. Entry into the European Common Market and changing tastes in the U.S. convinced the Triumph management to move to an open cockpit sports car with roll-up windows. Roll-up windows were not the only features which were considered desirable. The ventilation and heater system also needed to be fixed and the cockpit interior and luggage space needed to be enhanced. With these basic parameters in mind the Italian designer Michelotti came up with a wider, lower and more finely finished body than previous Triumph Roadster (TR) models. Bumper overriders were kept on the front bumper, but the headlights, parking lights and turn signals were all mounted in the grill. This opened the engine compartment by reducing the size of the front valence found on earlier TR’s. The hood (bonnet) was flattened out and hinged at the front. Since the body was now lower to the ground a hood bump was added to to allow for carburetor clearance. The fenders (wings) were flared out at the wheel wells to account for the new body’s wider track and the door handles were changed to a one-piece design with the lock built into the handle. Due to the fact that the doors contained roll-up windows the body line now continued parallel to the ground from the windscreen to the rear of the car. This allowed more space for luggage and spare tire stowage. The body exterior was uncluttered except for a TR4 badge on the hood, narrow stainless steel strips along the top (from the front of the hood to the windshield and then continuing from behind the cockpit to below the tail lights) and TR4 on the trunk lid. The letters TRIUMPH were also placed on the front of the hood and on the trunk lid. TR4 colors were shades of White, Black, Blue, Green and Red.

The body actually came in two versions although the company never capitalized on the fact that they were, in reality, offering a coupe as well as the roadster version. The first, and by far most popular version, was of course, the convertible (still called a roadster – although technically a roadster can not have roll-up windows). The Roadster version had a removable vinyl soft top with three plexiglass windows. The top was completely removed from the car and stored in the trunk when not in use. It was mounted on “hood sticks” which folded down into the rear of the cockpit and were then covered by a panel behind the seats. The convertible top was designed to be watertight by eliminating the front snaps which had held earlier TR model tops in place. The TR4 top had a metal strip inside the front edge. This strip was hooked into the top front of the windshield surround. When the top was installed and the roll-up windows were raised the design was effectively watertight (much more so than the earlier “side-curtains”).

For the TR4, Triumph offered an option called the “surrey top.” In reality, this made the convertible into a coupe. A permanent bolt-on metal section with a large rear window was fixed around the rear of the cockpit and a removable metal center section was placed over the seats. (Porsche and other auto-makers later used a similar design, calling it a “Targa top”). The “surrey top” removable section could not fit in the trunk, so a canvas section was provided in case one wanted to close up the cockpit when away from home. The “surrey top” was not popular at the time, probably because most people did not really understand what it was and Triumph did not market it correctly. (These are sought after today, maybe because we are familiar with “Targa’s” and “T-tops”).

The interior cockpit of the TR4 was roomier due to the new 4 inch wider body. In addition, the dash (fascia) had been moved forward which increased cockpit room from front to back. The dash was initially painted white with black vinyl padding along the top and bottom, but in the late ’63 or ’64 a highly polished mahogany veneered wood dash became standard equipment. (Because of the rich look, many early TR4’s have been retrofitted with wooden dashes). A deep, wide and lockable glove box (cubby) was provided on the passenger’s side of the dash. The tachometer and speedometer were positioned directly in front of the driver and gas, temperature, oil pressure, ammeter gauges (and an ashtray) were placed in the center of the dash. Also in the center underneath the dash was a lever connected to a vent scoop located on the outside in front of the windscreen. Opening this vent enabled fresh air to be drawn into the cockpit. Heat was provided by air passing through the heater located under the center of the dash. A fan then pushed the air either up onto the inner windshield or down to the floor. At the outer ends of the dash there were two square shaped vents which allowed unheated fresh air to be routed into the cockpit at chest level. This was a big improvement over the heating and venting systems of earlier TR’s.

Running vertically down from the center of the dash was a black metal plinth which was bolted to the cockpit floor. This strengthened the dash area and eliminated movement and rattling. The plinth also held the control knobs for various functions and was where the optional radio was installed.

The seats were initially the same seats as the in TR3 although the seat design was changed two more times before the TR4 was replaced in 1965. The seats were vinyl or optional leather in a choice of several colors. The doors, and the surrounding sides and rear of the cockpit, were covered in vinyl panels which matched the color of the seats. The doors also included map pockets and, as mentoned above, the 4 inch wider body resulted in more lateral room for the occupants.

The floor of the cockpit was covered forward of the seats with a ribbed black rubber mat held in place by snaps on the floor and clips on the inside firewall. From the front of the seats backward the floor was covered with charcoal-grey loop pile carpet. (This was the only carpet color available.) The transmission tunnel between the seats was carpeted fiberboard with the shifter handle coming through a ribbed rubber boot. A chromed hand-brake lever was installed on the right side of the transmission tunnel.

What Triumph now had was a modern looking, sleekly designed sports car with slightly better handling than earlier TR’s. This better handling was the result of the weight distribution and changes to the chassis, suspension, steering.

Although the basic frame (chassis) was the same as the TR3, several minor chassis modifications were made to accomodate Michelotti’s new body design. To accomodate the wider and heavier new body, the TR3 track needed to be widened by about 4 inches. This was done by welding a 2 inch long channel section on each of the TR3’s front box section chassis rails and extending the length of the rear axle (a two piece rigid axle) by 3 inches. This gave a wider track and a sleeker look – optional wire wheels could add another 1 inch of width. Body mounts were welded onto the extreme front of each chassis rail to eliminate body flexing. Rack and pinion steering, a definite plus, was added and although the front suspension members and steering geometry remained the same, the rear shock absorber mounts were reinforced because of the added body weight (about 70 lbs). The front suspension had wishbone arms with tubular shock absorbers inside helical coil springs. The rear suspension consisted of semi-eliptical leaf springs and lever action shock absorbers mounted on either side of the frame. Because