Get Running gear -> Axles Guide for Audi RS E Tron Gt 4 Door First Generation (2021-2026)

Running gear

Overview

The main system components of the running gear on the Audi e‑tron GT and the Audi RS e‑tron GT are largely identical. Any differ-

ences will be mentioned specifically in the following chapters. If information about the Audi e‑tron GT is given and no differences

are mentioned, the information also applies to the Audi RS e‑tron GT.

In the standard version, the Audi e‑tron GT is equipped with a steel spring running gear with electronic damping control. Air sus-

pension is available as an option in conjunction with electronic damping control (adaptive air suspension). The Audi RS e‑tron GT is

equipped with adaptive air suspension as standard. Both of the running gears are new developments or evolutions of those in cur-

rent Audi models.

The four-wheel steering system is available as optional equipment for the Audi e-tron GT. One of the highest priority development

goals was to achieve a low vehicle weight. The main axle components are therefore made of aluminum. Running gear control

unit J775 is also the coordination platform for the running gear systems in the Audi e‑tron GT.

If the required conditions have been met, recuperation takes place via the generator mode of the electric motor(s).The total brak-

ing power is then obtained from the hydraulic braking power and the braking power provided by the electric motor(s). The complex

regulation of these processes is performed by an electromechanical brake servo in conjunction with a 9th generation ESC system.

As on the Audi e-tron, the driver can set the level of recuperation by pulling the paddle levers on the steering wheel.

The standard version of the Audi e-tron GT is equipped with a generously proportioned steel brake system. Carbide-coated brake

discs or a ceramic brake system are available as optional equipment. The RS model has the carbide-coated brake discs as standard

equipment and can be equipped with the ceramic brake system as an option.

The range of available wheels spans from 19” (for the e-tron GT) and 20” (for the RS e-tron GT) in the standard equipment version,

to optional 21” wheels. Specially developed optimised rolling resistance tires reduce rolling resistance and help to increase the

range.

The third-generation Tire Pressure Monitoring System with direct measurement completes the comprehensive standard equip-

ment.

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Axles

Overview

The axles of the Audi e‑tron GT are evolutions on the basis of the axle technology of the Porsche Panamera and Porsche Taycan.

Double wishbone axles are used at the front and the rear. The rear axle is a double wishbone axle with separate upper wishbones.

This means that one wishbone is used for the lower section while the upper section is "split” into two individual wishbones.

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This type of axle construction mainly provides packaging benefits. In the development of this vehicle, a particular emphasis was

placed on lightweight construction. The subframe, wheel bearing housings and wishbones on the front axle are made of

aluminum On the rear axle, this applies to the subframe, hub carriers, wishbones and track rods.

Front axle

System components

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Subframe

The subframe is a welded construction made of four aluminum node castings connected by aluminum extrusions. This type of con-

struction allows for high rigidity and low weight. The lower wishbones, the steering rack, the anti-roll bar and the assembly mount-

ings are fitted on the subframe. Two reinforcement panels which are bolted to the subframe from below are used in addition to

increase rigidity.

The subframe is fixed in place on the vehicle body with bolts at six mounting points.

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Wheel bearing housings

The wheel bearing housings are hollow aluminum castings. The upper and lower wishbones and the steering rack’s track rods are

connected to them by ball joints. The brake calipers and wheel hubs/wheel bearings are bolted directly onto them. In the upper

section, they also provide the connections for the anti-roll bar coupling rods.

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Wishbones

The upper and lower wishbones are forged aluminum components. This manufacturing technology provides high mechanical rigidi-

ty under compression, tensile and bending loads while keeping the mass of the components low. The upper wishbones are connec-

ted to the vehicle body with large bonded rubber bushes. The lower wishbones are fitted in the subframe on the vehicle body side.

A bonded rubber bush is also used for the front mounting position; the mounting at the rear has a hydraulically damped bush. The

suspension struts are also connected to the lower wishbones.

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Hydro-bush of lower wishbone

Lower wishbone

Upper wishbone

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Anti-roll bar

Tubular anti-roll bars with coupling rods are used. These are coupled at the wheel bearing housings. The anti-roll bars are mounted

on the subframe in bonded rubber bushes.

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Wheel hub/wheel bearing

The wheel hub and wheel bearing are flanged to the wheel bearing housings as one unit. The wheel hub can be pressed out of the

wheel bearing in service. A magnetised impulse ring, which works as an impulse sender for the wheel speed sensor, is integrated in

the wheel bearing seal.

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Suspension/damper strut

Single-tube dampers (gas struts) are standard equipment and can be regulated in non-compression and compression stages. The

regulating valve inside (which has continuous adjustment) is activated by running gear control unit J775 via a wire going through

the piston rod. In the neutral condition (not electrically activated), the damping force is low (“soft” characteristic).

Steel springs are used in the standard equipment version.

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Service operations – new special tools

Several tools which were previously only used for assembly work on Porsche vehicles are used to remove/install axle components.

One example is the spring compressor VAS 6908, which is used to remove/install the suspension strut on the front axle (refer to

Workshop Manual).

Rear axle

System components

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Subframe

The subframe serves as the mounting for the wishbones, the anti-roll bar and the steering rack for the rear wheel steering (option-

al). It is decoupled from the vehicle body by four hydraulically damped bushes and made of aluminum gravity die casting.

If the vehicle is equipped with four-wheel steering, the rear wheel steering module is fitted instead of the cross member.

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Hub carriers

The hub carries are aluminum castings. The wishbones and track rods are connected with bonded rubber bushes. The wheel hubs/

wheel bearings are secured with flange connections. The brake calipers and the actuators of the electromechanical parking brake

are also connected to the hub carrier.

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Upper wishbones

The two upper wishbones are forged aluminum components. They are connected to the subframe and hub carrier with bonded rub-

ber bushes.

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Lower wishbones

The lower wishbones are made of aluminum and manufactured using the gravity die casting process. They are also connected to

the subframe and hub carrier with bonded rubber bushes. Cup-shaped indentations serve as mountings and supports for the

springs. The dampers are fitted in the outer section between the spring mountings and the connections for the hub carriers. The

coupling rods for the anti-roll bars are fitted in bonded rubber bushes at the side.

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Track rod

The track rods are forged aluminum components. They are connected to the subframe and the hub carrier via bonded rubber bush-

es. If the vehicle is equipped with four-wheel steering, the connection on the axle side is made in the forks of the rear axle steering

rack’s spindles.

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Wheel hub/wheel bearing

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Running gear -> Axles for Your Audi RS E Tron Gt 4 Door First Generation (2021-2026)

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