Permanent 4
The Alfa Romeo 33 has turned 40 years old. The successor to the Alfasud lasted until 1994 after several facelifts. In the twilight of its career, the Alfa Romeo 33 received automatic four-wheel drive. The Italians even talk about permanent 4WD, but is that really the case, or is the marketing department going a bit too fast here?
In 1984, Alfa Romeo presented the 33 4×4, a 33 with manually selectable four-wheel drive. The drive system is similar to that of the Fiat Panda 4×4 and works with a lever located just in front of the gear lever. In 1991, a year after the major facelift, an automatically operating 4WD system was also introduced in combination with the 1.7 16-valve. The lever to engage the rear wheels disappears, the electronics will now take care of that. The car now goes through life with the addition Permanent 4.
Differential between gearbox and engine
In principle, the 33 is a front-wheel drive with the four-cylinder boxer engine in front of the front axle and the gearbox behind the front axle, the differential is located between the box and the engine. On the Permanent 4, there is an electronically controlled electromagnetic dog clutch at the rear of the five-speed manual transmission that establishes the connection to the propeller shaft. To compensate for speed differences between the front and rear axle, you will see a viscous coupling in the cardan shaft – near the front seats. When there is no speed difference between the front part of the propeller shaft and the rear part, the viscous coupling does virtually nothing, so there is hardly or no four-wheel drive. Oh, and if the electromagnetic clutch is open under certain circumstances, there is no connection between the front and rear axle and therefore no four-wheel drive. The connection between the front and rear axle is therefore not permanent. When naming the car, the marketing department probably means that you no longer have to switch on the 4WD yourself, or that the electronics are permanently calculating whether the clutch should be opened or closed.
See-through plate of the Alfa Romeo 33 Permanent 4.
Flywheel rear differential to filter out imbalance
A nice detail on the drawing is the flywheel at the front of the rear differential, which serves to filter out imbalances in the drivetrain. The axle shafts run to the wheels through the tubes bolted to the differential. The rear axle is of the rigid type and is held in place transversely by the curved Panhard rod that you see running across the front of the differential. Normally the 33 has drum brakes at the rear. However, the specimen in the drawing is equipped with discs, a standard feature for specimens with ABS. The anti-lock braking system is only available on the 33s with electronic petrol injection, such as this 1.7 IE 16V Permanente 4, which has been known as the 1.7 IE 16V Q4 since 1992.
– Thanks for information from Autoweek.nl