Rambler Engineering

by Ralph H. Isbrandt, Vice President
Automotive Engineering and Research, American Motors Corporation

Motor Trend / February 1963

When we decided to design and engineer a new Rambler Classic Six and Ambassador V-8 for 1963, we laid down certain ground rules to keep the results within our compact car concept. Among the most important: to maintain a balance between economy and performance, and to make changes only when they improve the product and provide greater benefits to the owner -- not for the mere sake of change. Another big consideration during our development stage was overall product quality, reliability, and durability. Rambler's reputation in these areas had to be maintained or exceeded. From the very beginning we had to have close liaison between research, engineering, styling, manufacturing, purchasing, and sales.

To meet our objectives, we established five design criteria for the 1963 models based on our experience with previous Rambler designs:

  1. Interior dimensions and seating positions should be the same or improved;
  2. Exterior dimensions shouldn't be bigger, and reduced if possible;
  3. Entry and exit room should be the same or improved;
  4. Weight should be reduced by about 150 pounds or more;
  5. All features that have proven successful in increasing the value of the car should be retained.

The wheelbase dimension wasn't a primary design yardstick. Wheelbase evolved naturally after the interior and exterior dimensions were determined. We settled on a final wheelbase of 112 inches (over the previous 108 inches) because it provides the best interior room within the established exterior dimensions. It also gives maximum benefits without affecting handling or turning radius.

The most important single engineering advance in the new Rambler Classic and Ambassador is the entirely new single-unit body construction. As the acknowledged U.S. pioneer of unit body construction, we believe the new body will help us hold our leadership in this method of construction. It's the result of engineering and manufacturing studies that started early in 1958, culminating in a stronger, safer body plus greater precision and quality in manufacturing. We firmly believe this new body concept has pl aced us several years ahead of the industry.

Our initial goal was to develop a unit body with the ultimate in "designed-in" qualities, combining measurable weight reduction, maximum strength, and advanced manufacturing techniques. As a pioneer of unit bodies in this country, we believe we've successfully met this challenge.

Quality was designed into the single-unit body through a unique integration of basic structural components -- a completely new concept upon which the overall design was based. The concept of integration of structural components into single stampings reduced the number of parts and sub-assemblies in the new sedan body from 346 to 244 -- or 30 per cent. This lowered the number of welded joints, contributing to weight reduction.

Better corrosion resistance was another important goal of our new body program. WE used more galvanized steel and reduced the number of welds in many critical corrosion areas. The 1963 Rambler Classic and Ambassador use 124 pounds of galvanized steel, compared with some 17 pounds on 1962 models. A total of 27 body parts are galvanized, compared with two in 1962.

Besides more corrosion-resistant galvanized steel, all sheet metal parts are still being treated with the "Deep Dip" protective bath pioneered by American Motors in 1958. In this process, the body structure is immersed in a chromate primer tank so the protecting chemicals can penetrate areas not reached by the conventional spray methods.

The new uniside design is revolutionary and exclusive to Rambler. In the past, the uniside was made by the welding together of 52 stampings to form one complete unit Our present uniside is a one-piece stamping which permits production uniformity and better door fittings.

The uniside is made of an inner and outer stamping, both formed from a single sheet of steel. These two stampings are then welded together. Consequently, the door openings are exactly controlled, because the single stampings are all consistently drawn in the same dies. There's no chance for door openings to vary due to human error or variations in fixtures and jigs. The result is a more rigid structure with greater quality.

To further increase the strength of the body, front and rear floor pans, as well as the windshield and rear window openings, are of one-piece stampings. The entire front end structure, including upper and lower front crossmembers, are welded into the body structure. The upper front suspension coil spring seat is made of galvanized steel. To facilitate removal and repair, the front fenders are bolted on.

Improved entrance and seating were important considerations in the initial planning stages of the new unit body. We adopted curved side glass (which moved the roof rails inward) and a step-down design (permitting chair-height seats and comfortable head ro om). The step-down design necessitated a complete redesign of the bottom sills and rocker panels of the uniside assembly.

Ramblers' curved side windows, previously used on only some of the most expensive American cars, helped us improve our cars' styling and proportions. Our decision to adopt curved glass was a tough one because of the increased cost. Still, we felt the improved looks, the fact that the curved glass permitted greater interior room, easier exit and entrance, and reduced wind noise justified our decision.

Overall, the new concept of integration of structural components has contributed to improved body durability. Not only have we been able to reduce the number of individual pieces, but the welded joints are located outside highly stressed areas. Finally, the entire new body design permits the use of the best types of welding throughout.

Powerplant isolation has always been a major concern to automotive engineers. To maintain Rambler's leadership, we started an extensive development program in this area. After investigating several possibilities, we adopted a new three-point engine mounting instead of the more conventional four-point mounting. We found it greatly improved engine smoothness at all engine and car speeds.

The two front mounts are new. They were moved rearward on the engine block to a position at the center of gravity. The two rear mounts formerly used on the bell-housing were replaced by a single mount on the rear of the transmission. The rear mounting pad is attached to a new rear crossmember mounted in rubber, plus a stabilizing thrust rod to absorb driving forces. This tripod engine mounting also helped to lighten the front end weight to further reduce steering effort and still maintain our steering precision.

The front suspension we adopted last year was incorporated into the new models with only necessary modifications to fit the new body.

While we already offered the widest choice of transmissions in the industry -- standard, standard with overdrive, E-Stick, E-Stick with overdrive, and automatic -- a certain segment of car buyers showed a preference for a stick shift on the floor. We investigated and tested several systems before adopting the new Twin-Stick transmission.

The shift lever of this new "floor-shift, five-speed overdrive" transmission is located on a console between the two front seats, with the overdrive IN/OUT control lever to the right -- thus the name Twin-Stick. Five closely spaced ratios provide maximum flexibility in selecting engine speeds to meet a variety of driving situations. Gear shift lever travel is held to a minimum for quicker, more positive shifting action.

On top of the shift lever, a spring-loaded button gives instant kick-down from overdrive to direct gear. The throttle doesn't actuate kick-down as on regular overdrive. A signal light on the console indicates overdrive engagement.

In addition, we've added the E-Stick automatic clutch transmission (which eliminates the clutch pedal) to the Rambler Classic line after its successful introduction on the Rambler American last year. We've also made several improvements in the transmission, including a new vacuum control system for quicker clutch release, and a new self-adjusting clutch mechanism eliminating periodic adjustments. All transmissions on 1963 Ramblers, automatic and manual, are permanently lubricated an never require draining or refilling. Rear axles also are lubricated for life.

Since car design is a complex process involving intelligent consideration of many factors -- customer acceptance, reliability and durability, service costs, economy of operation, and manufacturing costs -- our engineering department studies all phases in weighing its final engineering decision on any given change.

As a case in point, we weighted all the above factors before deciding to eliminate the push-button selector for the lever system on Classic and Ambassador models equipped with automatic transmission. Since the lever is used fairly generally throughout the industry, most buyers showed a strong preference for this system. Also, having consistently used the lever system in the Rambler American line, many Rambler buyers pointed to the non-uniformity in the same family of cars.

Although they can't be seen, we've made many improvements and refinements in our Six and V-8 engines to increase their efficiency, economy, and service life. We have a constant program of testing to develop the best engine possible. Maintaining our original thesis, we kept some of the engineering features that have contributed to the success and greater value of the entire Rambler line.

An improved dual master cylinder, with self-adjusting brakes, is again standard on all Ramblers. We believe the extra cost is well worth the safety it provides Rambler buyers. The system has separate hydraulic units for front and rear brakes. Should either fail through accident or neglect, the other unit will continue to operate.

Another feature that has resulted in vast savings to our buyers has been the guaranteed-for-life, ceramic-armored exhaust system offered as standard equipment on all Rambler models -- a first in the industry. Besides the muffler and tailpipe, the exhaust pipe from the rear of the engine to the muffler has also been ceramic coated on 1963 models.

On the Classic and Ambassador V-8, the new muffler is relocated transversely behind the rear axle in a more protected position for quieter operation and less heat transfer to the passenger compartment.

While it's virtually impossible to point out all the engineering effort that's gone into the redevelopment of the 1963 Rambler, we believe the highlights presented here are indicative of the time, energy, and thought that have gone into a product ot give consumers the best vehicle possible

We're extremely proud that Rambler has receive Motor Trend's Car of the Year award. Inasmuch as the award is primarily based on an exhaustive analysis of functional engineering design, such recognition is particularly meaningful to the many people of American Motors whose efforts have contributed so much to further extend Rambler's pioneering basic excellence in the compact car field.