A new variation on the planetary design is the Ravigneaux gear set. This gear set is capable of 4 forward gears and one reverse. However, depending upon application it may be used with an auxiliary gear set. Here are some examples:

A4S310/270R uses the Ravigneax set for 3 forward gears and one reverse. Overdrive is obtained by the auxiliary gear set.
A5S310Z uses a combination of the Ravigneaux gear set and the auxiliary gear set to obtain 5 forward gear and one reverse. First, second and reverse gears are achieved by using a combination of both gear sets.
The A5S360/390R uses a modified version of the ravigneaux set that provides five forward gears and one reverse. There is no auxiliary gear set used.

Characteristics of the Ravigneaux Gear Set are:

NOTE: The Ravigneaux Gear Set shown below is a typical representation, refer to Fig 1. There are a few variations of this arrangement used on BMW transmissions.

One planetary carrier which is common to both sets of planetary pinions.
Two sets of planetary pinions, one long set with small diameter and one short set with large diameter.
Two sun gears, one input sun gear and one reaction sun gear.
One common ring gear.

Fig 1: Identifying Ravigneaux Gear Set
Courtesy of BMW OF NORTH AMERICA, INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Ravigneaux Gear Set

Use the Manual With the Right Hardware

When to See a Mechanic

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