Usage:
D11N, 776B Tractors;
777B, 785, Trucks
- SUPPLEMENT: 05/21/90
SERVICE MAGAZINE; JULY 24, 1989; PAGE 13; "Stronger Support For Turbocharger Exhaust Elbow And New Coupling Used" for D11N, 776B Tractors; 777B, 785 Trucks. The 9Y7672 Coupling is not used in 785 Trucks. The 7N4901 Coupling used in 785 Trucks was omitted in the article.
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Description of Change: The support of the turbocharger exhaust elbow on the above machines has been improved as follows.
-
- ... A new elbow support is used. See illustration. It has a thicker cross section, and higher temperature material is used in the iron casting.
Right side view of new parts installed.- ... The new elbow support is bolted to a sleeve between the two rear exhaust manifold sections. The sleeve, which is an added part, has a mounting pad for the support. The new support and sleeve are designed so they are directly under the weight of the exhaust elbow connection. The support pad on the former elbow support was offset from the weight of the exhaust elbow connection.
- ... A new exhaust manifold section is used to which the turbocharger is bolted. The pad to which the former elbow support was bolted has been removed from the manifold section to make clearance for the new elbow support.
- ... A new elbow support is used. See illustration. It has a thicker cross section, and higher temperature material is used in the iron casting.
Also, a new coupling connects the new support to the turbine housing. This coupling has a larger chamfer to eliminate wear in the turbine housing bore that could occur because of misalignment between the turbocharger and the former support.
Adaptable To: The new parts are effective with the following ENGINE serial numbers:
- D11N Tractor: 99W1414
- 776B Tractor: 99W1466
- 777B Truck: 99W1466
- 785 Truck: 96Z439
- 776B Tractor: 99W1466
The new parts, all used together, can be installed in place of the former parts as shown. (No gaskets are used between the former or new manifolds.) Lubricate the washer faces and threads on the 12-point bolts and locknuts that fasten the supports to the manifold sleeves before tightening. Then tighten to 55 ± 7 N·m (40 ± 5 lb ft).
