PROBLEM

Root cause has been identified as a machining process change made by the gear supplier, which had an undesirable effect on the surface finish of some idler gear bushings. Copper content in the oil has been identified as an accurate method for predicting whether the engine will be affected by the accelerated wear condition.

(expressed as Cu).

NOTE: Oil samples should be taken during routine service intervals (unless an oil sampling program is already in existence with predetermined intervals which are more frequent than the normal service intervals).

 While elevated copper levels from SOS sampling can effectively identify accelerated idler gear bearing wear, occasional hard cold starting difficulties may also indicate premature idler gear bearing wear.

AFFECTED PRODUCT

PARTS NEEDED

ACTION REQUIRED

Remove all 232-3668 parts from parts stock.

An oil sample must be taken from all engines in the affected product range. The oil sample report must be attached to all claims that include an idler gear change. Make every effort to administer this program in a timely manner, but with the least incursion into the customers? operation. Taking oil samples at the normal maintenance interval, especially where Customer Support Agreements are in existence, or where customers already use Scheduled Oil Sampling, is advised to keep program costs to a minimum. This program also affords an opportunity to promote CSA?s and SOS with customers not currently enrolled.

Cu 0 - 50-ppm Change oil & recheck at 2nd service (no longer than 1000 hours of engine service)

Cu 51 - 100 ppm Change oil & resample after a further 250hrs

Cu > 101 ppm Rework idler gear assembly

Oil sample results at 2nd check (750 hrs)

Cu 0 - 50 ppm No action required

Cu > 51 ppm Rework idler gear assembly

Oil sample results from 2nd service

Cu 0 - 50 ppm No action required

Cu > 51 ppm Rework idler gear assembly

If no evidence of elevated copper levels have been found in the oil samples after 1000 hours of service (above 50 ppm over 2 service intervals), the engine should be considered unaffected by this issue and no further testing or action is required.
 
 

The following process flow explains the policy and actions required.

The results of the oil sample are the most accurate method of determining whether or not the idler gear bearing has worn, or will wear prematurely. Copper level in early oil samples may be artificially elevated due to engine break in. Keep in mind the other factors used to determine an idler gear bearing problem:

• Hard starting

• Engine miss or stutter

OWNER NOTIFICATION

SERVICE CLAIM ALLOWANCES

Submit one claim for all 232-3668 parts removed from parts stock.

PARTS DISPOSITION

MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.

Attach. (1- Rework Procedure)

1. Remove alternator adjusting link and belts if fitted.
2. Remove water pump and joint, not removing the 2 bottom-left screws which retain the water pump the cover, as shown:

 

 

3. Remove timing case cover
4. Remove injector cover to gain access to glow plugs
5. Remove glow plugs to enable the engine to be turned

 

 
 
 
 
 
 
 
 

6. Turn the engine in direction of rotation to enable the crankshaft and camshaft locating pins to be fitted. Insert 230-6283 Crankshaft timing pin through the housing (front) and into the web of the crankshaft. Insert the 230-6284 Camshaft timing pin through the camshaft gear and into the housing (front).

Idler Gear Removal

1. Remove the three idler fixing screws (6) and the thrust plate (7).



 
 
 
 

2. Note the single mark on the FIP gear may not be aligned with the two marks on the idler gear. The idler gear marks ?walk? and several more rotations would be required to align the marks. This does not matter.


DO NOT remove the FIP gear and do not lock the FIP.

3. Remove the camshaft timing pin, leave the crankshaft locating pin in place. Remove the Camshaft gear fixing bolt (1) and remove the camshaft gear (2). Dependant on the ?fit? this may need a puller.




4. Now withdraw the idler hub and gear. Note: To remove the idler hub and gear insert three M10 screws back in the idler hub after removal of the plate, but make no attempt to screw the fixing into the thread. Now grab the three fixings and squeeze so that they lock into the hub, then move them about and pull to disengage the spigot from the cylinder block. Angle the hub and gear so that you can draw it out. Remember that because of the helix and the locked crank gear any other gear must be free to rotate as the teeth are disengaged.

 

 

5. Ensure all mating surfaces are clean, Re-assemble Gear Train

 

 

6. Turn the FIP gear so that the single mark is pointing at the crankshaft.

 

 

7. Fit the new idler hub and gear (lubricating with clean engine oil) so that the pair of marks on the idler enclose the single mark on the FIP gear. This may need more than one attempt since the correct crank gear tooth must be meshed with the idler to bring the marks in line with the gear centre-line.

 

 

8. Fit the new thrust plate and screws and torque to 44Nm. Check that there is end float and backlash.

 

 

9. Refit the camshaft gear. This is located on the camshaft by the key-way and the helix means that the camshaft must rotate slightly as the gear is pushed home. The gear must fit so that the marks and locating pin all align / fit. If the idler has been fitted on the wrong crankshaft tooth this will not be the case. Check for backlash.

 

 

10. Refit the camshaft gear fixing bolt and washer. Tighten to 95Nm but do not use the locating pin to prevent the engine from turning.

 

 

11. Remove the pins and rotate the crankshaft circa 90 degrees anticlockwise. Rotate it clockwise towards TDC until the crankshaft locating pin can be fitted. Check that the timing marks all align and the camshaft locating pin will fit.

 

 

12. Rebuild to running condition using new gaskets.

Timing Case cover and water pump screws 22Nm.

Glow plugs 15Nm.