PISTON & ROD GP 6L2868 - Caterpillar

of these engines were inspected and/or reset eitherat Caterpillar or the OEM factory. Those engines were marked with the letters"YD" stamped near the serial number plate on the cylinder block. Enginesalready marked "YD" are not affected by this Service Letter.
Model IdentificationNumber
C-10Truck 3CS24644-24790
C-12Truck 2KS77195-776329SM2294-23709NS20382-20396
C-10Industrial BCX483-511
C-12Industrial BDL627-703
3196Marine 2XR4639-4661PARTS NEEDED
No parts needed Valve cover seals should reused.ACTION REQUIRED
See the attached Rework Procedure.SERVICE CLAIM ALLOWANCESFor Truck Engine applications, claimas follows: Code 1105-025, Inlet / Exhaust Valve(s) Adjust. Allowable timesper chassis are as follows:
SC MC CV CO
2.4 1.9 1.7 1.9For all other applications, claim asfollows:
Product smu/age whichever comes first Caterpillar Dealer Suggested Customer Suggested
Parts Labor Hrs Parts Labor Hrs Parts Labor Hrs
0-400000-12 mos 100% 2 0 0 0 0
This is a 2.0?hr job.PARTS DISPOSITION
Handle the parts in accordance with yourWarranty Bulletin on warranty parts handling.Attach. (1-Rework Procedure)Rework Procedure
Inspect the serial number plate area onthe cylinder block (right rear corner of block) to determine if the letters"YD" are stamped on the block. If stamped "YD", then the engine has alreadybeen reworked and no further action is necessary. If there is no "YD" stamp,proceed with the rework procedure.
Visually inspect the valve rocker armsto see if there are any loose or missing adjusting screw jam nuts. If anynuts are missing, locate and retrieve the missing nut(s). Do not reuseany nuts that may have backed off; replace as necessary.
Depending on the miles/hours on the engine,identify the extent of service required as follows:
For affected engines with LESSthan 10,000 miles / 16,000 km / 300 hours, only valve lash adjustmentis required. For these low hour engines, the normal complete overheadadjustment maintenance must still be performed on schedule as specifiedin the Engine Operation and Maintenance Manual.For engines over 10,000 miles /16,000 km / 300 hours, the normal COMPLETE overhead adjustment (includingvalves, injectors, and Jake Brake) should be performed under thisPSP. In this case, this initial adjustment will sufficefor the normal first scheduled overhead lash adjustment. The normal publishedmaintenance schedule should be followed thereafter, for the second overheadlash adjustment and beyond.
Adjust Valve Lash (Both Inlet and Exhaust)per normal procedure specified in the Engine Service Manual. For reference,the standard valve lash specifications are:
Valve Lash Setting Specifications:Inlet = 0.38 mm (0.015 inch)
Exhaust = 0.64 mm (0.025 inch)
Valve Adjusting Nut Torque = 25+7 N m (18 + 5 lb ft)
Removal of Jake Brake housings(if equipped) is not required for valve lash adjustment only on low-hourengines. However, if the Jake Brakes are removed they should be re-adjusted? note that the lash settings are different for C-10 and C-12 engines.The specifications are: Jake Brake Slave Piston Lash Specifications:C-10 0.64 mm (0.025 inch)
C-12 1.02 mm (0.040 inch)
When the procedure is complete, stampthe letters "YD" to the right of the engine serial number plate onthe cylinder block to verify that this rework has been completed.