0336639 JOHNSON SCREEN

The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS8847" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
This Revised Service Letter replaces the March 5, 1997 Service Letter. Changes have been made to the Affected Product and Parts Needed.
Termination Date
March 31, 1998Problem
The exhaust manifold joints may seize up, causing the bolts that attach the manifold to the cylinder head to break due to expansion of the manifold. Bolts mainly break on the end of the manifold. A new seal and sleeve should be installed on the end sections of the manifold to prevent this from occurring.
Affected Product
Model & Identification Number
Group 1
D11N (74Z235-1152)
776B (6JC45-108)
777B (4YC59-838, 4YC840, 4YC841, 4YC843, 4YC848-852, 4YC854, 4YC863, 4YC877, 4YC999)
784B (5RK12-25)
785 (8GB118-697, 8GB862)
785B (6HK101-704)
789 (9ZC111-677)
789B (7EK111-568)
994 (9YF6-210)
5230 (7LL21-74)
The following list of new or remanufactured engine serial numbers are eligible for this program if they are either in dealer's Parts Stock or are a swing engine.
3508 (99W1-3518, 7YG1-2001 )
3512 (96Z1-921, 4WJ1-903 )
3516 (54Z1-1165, 2PK1-1360 )
Reman (3508) (4ZL1-375, 5TL1-200)
Reman (3512) (5EL1-125, 6FL1-119)
Reman (3516) (7CL1-359, 6CL1-223)
Group 2
793 (3SJ6-56)
793B (1HL12-524)
The following list of new or remanufactured engine serial numbers are eligible for this program if they are either in dealer's parts stock or are a swing engine.
3516 (54Z1-1165, 2PK1-1360 , 7TR1-217 )
Reman (3516) (7CL1-359, 6CL1-223)
Group 3
D11N (4HK361-635)
D11R (8ZR297-393)
776C (2TK76-114)
777B (4YC839, 4YC842, 4YC844-847, 4YC853, 4YC855-862, 4YC864-876, 4YC878-998, 4YC1000-1866 )
777C (4XJ77-1123)
5130 (5ZL21-118)
The following list of new or remanufactured engine serial numbers are eligible for this program if they are either in dealer's parts stock or are a swing engine.
3508 (99W1-3518, 7YG1-2001 )
Reman (3508) (4ZL1-375, 5TL1-200)
Parts Needed
Group 1
16 - 5M2894 Washer16 - 2N2766 Locknut*12 - 4P7680 Spacer16 - 5P3961 Bolt16 - 5P2755 Bolt 4 - 7W8145 Gasket* 4 - 1138189 Spacer 4 - 1278269 Seal 8 - 1305274 Sleeve*As stated in the August 25, 1995 Service Magazine, this hardware, which is used to attach the exhaust manifold to the cylinder head, may not work with earlier exhaust manifolds.If an engine has the earlier exhaust manifolds, complete the following steps:- Increase the 21 mm spot face on the manifolds for the bolt spacer to 25 mm.- Enlarge the bolt holes from 11 mm to 13 mm.- Use a quantity of four 1138189 Spacers for each cylinder to attach manifold to cylinder head instead of three 4P7860 Spacers and one 1138189 Spacer.Group 2
4 - 7E4108 Seal16 - 5M2894 Washer16 - 2N2766 Locknut16 - 4P7680 Spacer16 - 5P2755 Bolt16 - 5P3961 Bolt 4 - 1278269 Seal 8 - 1305274 Sleeve If the engine has two exhaust cross-over pipes, use the optional parts to eliminate the rear cross-over pipe.
Optional Parts
1 - 1102746 Manifold1 - 1102747 ManifoldGroup 3
16 - 5M2894 Washer 16 - 2N2766 Locknut* 12 - 4P7680 Spacer 8 - 5P2755 Bolt () 8 - 5P3345 Bolt 16 - 5P3961 Bolt 4 - 7W8145 Gasket* 4 - 1138189 Spacer 4 - 1278269 Seal 6 - 1305274 Sleeve 1 - 1335916 Sleeve 1 - 1417098 Sleeve*As stated in the August 25, 1995 Service Magazine, this hardware, which is used to attach the exhaust manifold to the cylinder head, may not work with earlier exhaust manifolds.If an engine has the earlier exhaust manifolds, complete the following steps:- Increase the 21 mm spot face on the manifolds for the bolt spacer to 25 mm.- Enlarge the bolt holes from 11 mm to 13 mm.- Use a quantity of four 1138189 Spacers for each cylinder to attach manifold to cylinder head instead of three 4P7860 Spacers and one 1138189 Spacer.Action Required
1. Inspect the male side of the exhaust manifold to determine reusability, replace if necessary. Do not reuse the bolts and the locknuts.
2. Run the new 5P2755 Bolts down to close the gap with minimum torque, without crushing the seal.3. Tighten the new 5P2755 Bolts in a crossing pattern to a torque of 50 5 N m.4. Re-tighten the new 5P2755 Bolts in the same crossing pattern to 50 5 N m.Service Claim Allowances
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.