PRODUCT SUPPORT PROGRAM FOR REWORKING FAILED REAR AXLE PINION SHAFTS IN THE DIFFERENTIAL GEAR GROUP ON CERTAIN 902, 906 AND 908 COMPACT WHEEL LOADERS Caterpillar
PRODUCT SUPPORT PROGRAM FOR REWORKING FAILED REAR AXLE PINION SHAFTS IN THE DIFFERENTIAL GEAR GROUP ON CERTAIN 902, 906 AND 908 COMPACT WHEEL LOADERS
Usage:
REBE2455-05
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08Oct2007
(Revised 21Sep2010)
U-511
A-417
D-410
O-441
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After Failure Only
Parts stock action needed
PRODUCT SUPPORT PROGRAM FOR REWORKING FAILED REAR AXLE PINION SHAFTS IN THE DIFFERENTIAL GEAR GROUP ON CERTAIN 902, 906 AND 908 COMPACT WHEEL LOADERS
7750
PS51370
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NOTE:
This Program can only be administered after a failure occurs.
The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS51370" as the Part Number
and "7755" as the Group Number. Use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
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NOTE:
When submitting claim for Parts Stock Action, Use the appropriate 99Z as the s/n, the appropriate Service Letter Program Number as the Part number in the Part Causing Failure field,
"7755" as the Group Number, "56" as the Description Code.
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NOTE:
Although this Program is to be administered as described above on the Affected Product,
parts should be removed from parts stock as soon as possible.
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NOTE:
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.
NOTE:
This Revised Service Letter replaces the 08Oct2007 (Revised 20Jan2010) Service Letter. Changes have been made to remove the DSN note from the Action Required and the Parts Age/Hours has been removed from the Service Claim Allowances.
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TERMINATION DATE
31Oct2010
PROBLEM
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The pinion shaft in the rear axle differential may fail on certain 902, 906 and 908 Compact Wheel Loaders. A stack up of tolerances in the axle, axle mountings and the frame coupled with clearances in the trunnion bearings can lead to the pinion shaft or the pinion drive coupling failing due to bending fatigue. If the pinion shaft or the drive coupling fail then drive is lost to the machines rear axle.
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 3% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 2% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.
ACTION REQUIRED
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****Parts Stock ****
Remove all 284-3872, 284-3873, 284-3874 from dealer parts stock.
****Affected Product****
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Determine which differential gear group is needed for your machine before ordering the parts needed. See the attached Rework Procedure. Part Number 3125910 Limited Slip Differential Part Number 3125909 Standard Differential Part number 1U9891 Used in Limited Slip Differential Only
Note: Group 1 and 2 machines both require the same parts for the rework
Before refitting the axle, check the condition of the trunion bearings. If they show signs of wear, they should be replaced. To prevent wear, they must be greased at the required intervals stated in the OMM. This can not be claimed against the service letter.
When submitting the claim shimming measurements for the trunnions must be included in the claim story
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SERVICE CLAIM ALLOWANCES
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****Parts Stock****
Submit one claim for all parts removed from dealer parts stock.
****Affected Product****
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Product smu/age whichever comes first
Caterpillar
Dealer Suggested
Customer Suggested
Parts %
Labor Hrs%
Parts %
Labor Hrs%
Parts %
Labor Hrs%
*******Group 1*******
0-5000 hrs, 0-36 mo
100.0%
100.0%
0.0%
0.0%
0.0%
0.0%
NOTE: This is a 16.0-hour job for Group 1
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Product smu/age whichever comes first
Caterpillar
Dealer Suggested
Customer Suggested
Parts %
Labor Hrs%
Parts %
Labor Hrs%
Parts %
Labor Hrs%
*******Group 2*******
0-5000 hrs, 0-36 mo
100.0%
100.0%
0.0%
0.0%
0.0%
0.0%
NOTE: This is a 16.0-hour job for Group 2
PARTS DISPOSITION
****Parts Stock****
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
****Affected Product****
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Rework Procedure
1) Refer to the relevant service manual sections to replace the differential assembly and the drive group shaft. SENR1283 - 902 - 906 Wheel Loader Power Train. RENR2831 - 908 Wheel Loader Power Train 2) Use 8 Litres of 2P9863 (Bulk) Gear Oil API GL-5 in standard axles. In axles fitted with a limited slip differential use 7.5 Liters of Gear Oil and add 0.5 Liters of 1U9891 Additive. 3) Before installing the reworked drive unit on to the axles, apply a small amount of grease, 5P0960 to the spline of the pinion shaft assembly. Failure to do so will result in premature spline wear and early pinion shaft failure. 4) If the axle has been removed from the machine and the drive unit is assembled to the axle assembly prior to installation, it is necessary to use a ratchet strap or similar retention devise around the axle and the drive group-transfer to prevent the drive group-transfer from sliding off the axle.
Before refitting the axle, the axle mounts on the chassis must be checked and if required shimmed flat. Use the following procedure for shimming the axle.
Before refitting the axle, check the condition of the trunion bearings. If they show signs of wear, they should be replaced. They must be greased at the required intervals stated in the OMM.
Method for measuring 906 / 908 frame Axle mountings
Equipment needed.
A straight edge. The one shown is 450 X 40 X 15mm. If the straight edge is too long it will interfere on the frame. A set of metric feeler gauges.
Image1.2.1
Measure the axle mounts at the following positions A,B,C and D by placing a straight edge across between the 2 axle mounts. Hold it, so that the straight edge rests on both the front and rear mount. If there is a gap, slide a feeler gauge in this between the straight edge and the mount, at the positions marked in the picture (either A,B,C or D). Record the gap measurement using the table supplied in these instructions.
Image1.3.1
It is important to hold the straight edge across the mounts so that it touches on both the front and rear plates. It will touch in a minimum of two places, one on each mount.
Image1.4.1
Using the feeler gauges, accurately check the gap at the front and rear of each mount. Do not forget, unless the axle is completely flat at least one point on each mount WILL read zero. Examples If both mounts are flat all readings could be zero B and C could read zero. A and D could read zero. A,B and C could read zero. A,B and D could read zero.
Image1.5.1
Image1.5.2
Move the straight edge to the other side of the frame and measure as before.
Image1.6.1
Use the below chart to document your measurements.
Image1.7.1
Shims should be used to make the axle mount flat. These can be made from an assorted shim steel pack.
Image1.8.1
Using your measurements cut shims out the appropriate thickness of material to approximately 60mmx10mm.
Image1.9.1
Place the shims to the appropriate places on the axle mounts to ensure that the axle is totally flat. Stick the shims to the mount using a thin smear of grease or small drop of loctite instant adhesive.
Image1.10.1
Image1.10.2
Using the feeler gauges in the same way as before, check the front and rear of each mount. Confirm that with the shims in place there is no gap between the straight edge and the mounts at points A,B,C and D.
It is important to hold the straight edge across the mounts so that it touches on both the front and rear plates. After shimming, it should touch at 4 places, 2 on each mount. For example touching at A,B,C, and D
