Usage:
D11N Tractors, 789 Trucks
Reference: Service Magazine; August 22, 1988; "Improved Turbochargers Used" on D11N, 776B Tractors; 777B, 785 Trucks.
Description of Change: The exhaust manifold sections used on D11N Tractors and 789 Trucks have been improved. The new exhaust manifold sections are made of a material that retains more strength at higher temperatures.
Adaptable As: The new exhaust manifold sections are direct replacements for the former exhaust manifold sections on D11N Tractors and 789 Trucks. The part numbers of the new and former exhaust manifold sections are listed in the chart.
The new 7C3282 and 7C3283 Manifolds are in effect with 3508 Engines 99W654-Up in D11N Tractors. The remainder of the new manifold section are in effect with 3508 Engines 99W1035, 1040, 1041, 1056, 1062-Up in D11N Tractors. All the new manifold sections are in effect with 3516 Engines 54Z212-Up in 789 Trucks.
Prior to the new exhaust manifolds, D11N Tractors had two engine arrangements. One was the 8N9602 Engine Arrangement (standard), which could be operated up to a maximum altitude of 1500 m (5000 ft) without derating. The other was the 7C2637 Engine Arrangement (altitude) which could be operated up to a maximum altitude of 2250 m (7500 ft) without derating. With the new exhaust manifolds and a new turbocharger housing (see the reference article), the two engine arrangements became identical. So the 7C2637 Altitude Engine Arrangement has been canceled. The 8N9602 Engine Arrangement can now be operated up to a maximum altitude of 2250 m (7500 ft) without derating and is in effect with 3508 Engines 99W1035, 1040, 1041, 1056, 1062-Up.
The standard and altitude engine arrangements for the 789 Truck have not changed because different turbochargers are used in each arrangement.