A second “deep reverse” gear will be added to Allison 4700 and 4800 model automatic heavy-duty transmissions, according to the company.
Available in mid-2010, the second reverse is designed to provide greater control and engine braking on steep grades, as well as better maneuverability in confined spaces. It will have a mechanical ratio of 17.12, giving it an effective torque converter multiplied ratio up to 32.5:1, according to Allison.
The new second reverse will be offered on the company’s Rugged Duty, Emergency Vehicle and Specialty Series automatic transmissions.
