848757 Volvo.Penta Tensioning arm

December 2, 2004
(Revised March 2005)
U-352
A-251
D-273
O-304
PriorityParts stock action needed PRODUCT IMPROVEMENT PROGRAM FOR SAMPLINGTHE ENGINE OIL, TESTING THE FAN / BRAKE PUMP OPERATION AND IF NECESSARY,REPLACING THE IDLER GEAR ASSEMBLY ON 3056E ENGINES INSTALLED IN CERTAIN924G, 928G, AND IT28G MACHINES
7542 PI30690
This Program must be administered assoon as possible. When reporting the repair, use "PI30690" as the Partnumber and "7751" as the Group Number, "56" as the Warranty Claim DescriptionCode and "T" as the SIMS Description Code. Exception: If the repair isdone after failure, use "PI30690" as the Part Number, "7751" as the GroupNumber, "96" as the Warranty Claim Description Code, and "Z" as the SIMSDescription Code. Make every effort to administer thisprogram in a timely manner, but with the least incursion into the customers?operation. Taking oil samples at the normal maintenance interval, especiallywhere Customer Support Agreements are in existence, or where customersalready use Scheduled Oil Sampling, is advised to keep program costs toa minimum. This program also affords an opportunity to promote CSAs andSOS with customers not currently enrolled. The information supplied in this serviceletter may not be valid after the termination date of this program. Donot perform the work outlined in this Service Letter after the terminationdate without first contacting your Caterpillar product analyst. This Revised Service Letter replacesthe December 2, 2004 (Revised February 2005) Service Letter. Changes havebeen made to the Affected Product.
COMPLETION DATE
TERMINATION DATE
June 30, 2005 December 31, 2005PROBLEM
There have been reports of premature wear on theidler gear bushing assembly and idler hub.Root cause has been identified as a machiningprocess change made by the gear supplier, which had an undesirable effecton the surface finish of some idler gear bushings. Copper content in theoil has been identified as an accurate method for predicting whether theengine will be affected by the accelerated wear condition.Rework of the idler gear assembly is recommendedif the copper content in the oil exceeds the threshold levels detailedbelow(expressed as Cu). Oil samples should be taken duringroutine service intervals (unless an oil sampling program is already inexistence with predetermined intervals which are more frequent than thenormal service intervals).
While elevated copper levels from SOS samplingcan effectively identify accelerated idler gear bearing wear, occasionalhard cold starting difficulties and occasional low engine oil pressurewarnings may also indicate premature idler gear bearing wear.AFFECTED PRODUCT
The affected serial number list shownbelow excludes machines that were repaired under an earlier field probeto determine the extent of this problem. Other machines may already havebeen repaired with parts announced in TIBU4161. While these machines maystill be included in the list below, there is no need to replace the idlergear assembly again. If your machine is in the affected productbelow and is a new machine being currently held in Dealer stock or inventory,apply this PI and re-work the Idlergear As. (There is no requirement tosample the oil).
Model Identification Number
924G DDA538, 543,546-547, 549-556, 558-589, 591-1053, 1055, 1182, 1188-1209, 1211,1225DFZ412-413, 415-546RBB266-267, 269, 288-291, 293-298,300-321, 323-333, 335-436, 438-490, 519, 573-575, 577, 586, 592, 614, 628
RTA155-160, 162, 164-185, 194, 239, 241,269WGX342-536, 637WMB357-572
928G DJD439, 456-457,461-492, 494-511, 513-711, 713-1006, 1011-1015, 1029-1033, 1035, 1039,1093WLG311-474,568, 579
IT28G DBT509, 515-517,519, 521, 523-524, 529-530, 533-636, 638-1107, 1117-1125, 1128-1130, 1133,1136, 1139, 1150WAC317-428PARTS NEEDED
Qty
Description
1 OILSAMPLING KIT
5 *3E8016 BOLT-LOCKING
3 6I0650 BOLT
1 1R0739 FILTERAS.-L
6 *8T4224 WASHER-HARD
1 *8T6870 BOLT
1 1772391 GASKET-COVER
1 2018745 GASKET-PUMP-
1 *2053665 PUMP GP-FAN
1 2514336 GEAR AS-IDLE
1 2546029 HUB-IDLERGE
1 2551209 PLATE-RETAIN