Usage:
NOTE: 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 "PS4774" 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.
NOTE: This Revised Service Letter replaces the March 31, 1999 Service Letter. Changes have been made to add additional parts to the Parts Needed for 938G\IT38G machines equipped with the standard 55 Amp alternator. Refer to Note C.
Termination Date
September 30, 2000Problem
There have been reports of Alternator and Air Conditioning V-Belt failures on Affected Products. These machines used a single V-Belt from the crankshaft pulley to the Alternator, and a single V-Belt from the crankshaft pulley to the refrigerant compressor, if equipped with Air Conditioning.
This Update includes the new Drive Group, pulleys and belts now used in production. A double V-Belt Set is used for the Alternator in a "triangular" drive configuration. This shortens the belt span on the tight-side, or drive-side, of the belts and improves belt stability. If equipped with Air Conditioning, the A/C refrigerant compressor is now driven by the pulley of the new drive group using a much shorter belt, which also improves A/C belt stability.
For machines equipped with the Attachment Axle Oil Cooler, this Program also includes an improved Clutch for the axle oil cooler pump. The new Clutch is to be installed at the same time the Belt Drive update is made (Note D).
Affected Product
Model & Identification Number
Refer to "Special Notes for Belt Drive Update" for more details of these Notes:
NOTE: Note A: Machines equipped with "Low Sound" and "Waste Handler" Attachments are not eligible for this Update, and are not included in the Affected Product
NOTE: Note B: Early IT38G-938G must have the A/C accumulator relocated (moved). Refer to Service Letter PS4798, " PSP For Relocating The Air Conditioner Accumulator On Certain 938G Wheel Loaders" PS4798 will be published soon after this letter is released.
NOTE: Note C: IT38G-938G with standard 55 Amp alternator requires a new adjustment strap and related parts. IT38G-938G machines with Attachment 134-8614 Lighting Group Auxillary, or the 141-8606 Alternator Arr. (70 amp_ requires different pulley and belts.
NOTE: Note D: 950G-962G when equipped with Attachment Axle Oil Cooler Group, the new crankshaft pulley and bolts are not needed, but a new Bracket and a new Clutch for the axle cooler pump are required.
Note B Machines, Earlier IT38G and 938G (A/C accumulator MUST be relocated, if equipped with Air Conditioning)
IT38G (1CW1-339, 1CW342 (Note A, B, C), 7BS1-505 ) (Note B, C)
938G (4YS1-626 (Note B, C), 6WS1-335 , 6WS337-530, 6WS532-748, 6WS750-768, 6WS770-1165, 6WS1167-1176, 6WS1178, 6WS1179, 6WS1181-1201, 6WS1203-1315, 6WS1317-1334, 6WS1336-1340 (Note A, B, C), 8RS1-295 (Note B, C), 9HS1-451 ) (Note B)
950G, 962G, IT62G, and Later IT38G-938G (relocation of A/C accumulator is not required)
IT38G (1CW343-345 (Note A, C), 7BS506-551 ) (Note C)
938G (4YS627-713 (Note C), 6WS1341-1351 , 6WS1353-1436 (Note A, C), 8RS296-345 (Note C), 9HS452-453 )
950G (2JS1-446, 2JS448-455, 2JS458, 2JS459, 2JS461-463, 2JS465, 2JS466, 2JS468-471, 2JS473-475, 2JS477-495, 2JS497-531, 2JS533-538, 2JS540, 2JS542-552, 2JS554, 2JS556-578, 2JS580-591, 2JS593-611 (Note A, D), 3JW1-733 (Note D), 4BS1-425 (Note D), 5FW1-181 , 5FW183-714, 5FW716, 5FW718-722, 5FW724-728, 5FW703, 5FW732, 5FW733, 5FW735-739, 5FW741-743, 5FW745-752, 5FW754-758, 5FW760-767, 5FW769-783, 5FW785-799, 5FW801-812 (Note A, D), 5MW1-333 8JW1-262 )
962G (3BS1-214, 3BS217-323, 3BS325-359, 3BS361-374, 3BS376-422 (Note A, D), 4PW1-262 (Note D), 5AS1-275 (Note D), 6EW1-226 6HW1-236 7BW1-203 , 7BW205-343, 7BW345-358, 7BW360-397) (Note A, D)
IT62G (6PS1-378 (Note D)
Parts Needed
("Low Sound" and "Waste Handler" machines are not eligible, See Note A)
(Earlier IT38G and 938G with Air Conditioning also need PS4798, "PSP For Relocating The Air Conditioner Accumulator". (Note B)
Additional Parts Needed to aid installation (See Procedure)
Action Required
This Update includes the new Drive Group, pulleys and belts now used in production. A double V-Belt Set is used for the Alternator in a "triangular" drive configuration. This shortens the belt span on the tight-side, or drive-side, of the belts and improves belt stability. If equipped with Air Conditioning, the A/C refrigerant compressor is now driven by the pulley of the new drive group using a much shorter belt, which also improves A/C belt stability.
For machines equipped with the Attachment Axle Oil Cooler, this Program also includes an improved Clutch for the axle oil cooler pump. The new Clutch is to be installed at the same time the Belt Drive update is made (Note D).
Machines with "Low Sound" (LS) and "Waste Handler" Attachments are not eligible for this update. Refer to Note A.
Refer to the attached "Special Notes for Belt Drive Update" for information necessary to order the correct parts.
Use the attached Procedure for Belt Drive Update" and the Illustrations for detailed instructions needed to perform the update.
Paint new parts as needed to prevent rust. Do not paint surfaces of bolted joints. Avoid excessive paint in pulley grooves.
Inform the Customer of new V-Belt part numbers, and make a note of them in Customer's Parts Manual.
Make a SIMS entry to report this update. Refer to the Procedure for details.
Service Claim Allowances
NOTE: This is a 4-hour job.
NOTE: Expenses for relocating the A/C accumulator (NOTE B) are NOT COVERED by this PSP.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.
- (1-Special Notes For Drive Belt Update)
- (2-Rework Procedure)
- (3-Illustrations)
- (4-Procedure for Replacement of Clutch)
- (5-List of Axle Oil Cooler Machines)
- (2-Rework Procedure)
Special Notes For Drive Belt Update
The following Notes explain some differences in the Affected Product, which may affect which parts are needed for a particular machine. The on-line JIZ111 Product Information System (PIS), or the Machine Shipping Order (MSO) can be used to determine the Attachments that were included for a particular machine serial number.
NOTE: NOTE A: Machines equipped with the "Low Sound" (LS)and "Waste Handler" Attachments are not eligible for this belt drive update, because they have have a different alternator and belt drive configuration, with the alternator located directly above the valve cover (above the crankshaft pulley). LS machines have a sound wall between the engine and the radiator; and LS machines have perforated service doorsand panels on the side of the hood. Standard machines do not have the sound wall, and have solid service doors and panels. "Low sound" machines have the same machine s/n prefixes as other machines sourced from Belgium, and have the following Attachment Numbers:
Machines equipped with Low Sound or Waste Handler Attachments have been excluded from the Affected Product. A separate Program will be released at a later date for these machines.
NOTE: NOTE B: Earlier IT38G and 938G machines equipped with air conditioning have the A/C accumulator located on a Plate assembly on the front of the engine, above the crankshaft pulley. This A/C accumulator mounting plate interferes with installation of the new Drive Group because of a welded vertical stiffening rib on the plate. On these machines, the A/C accumulator must be relocated and the mounting plate assembly replaced with a standard engine lifting eye, before the new Drive Group can be installed. The parts list and instructions for relocating the Air Conditioner Accumulator are described in Service Letter PS4798, " PSP For Relocating The Air Conditioner Accumulator On Certain 938G Wheel Loaders" PS4798 will be published soon after this letter is released. Earlier IT38G and 938G machines which do not have Air Conditioning have the standard engine lifting eye, and the Belt Drive Group update parts are directly adaptable.
Special Notice - After Failure Only: The PSP for relocating the A/C Accumulator will be announced soon for earlier IT38G and 938G machines. Until then, the new Belt Drive Update can be installed on these machines AFTER FAILURE ONLY by removing the lower part of the stiffening-Rib on the Plate for the Accumulator by cutting or grinding the rib smooth with surface of the Plate. Removing the lower part of the stiffening rib will allow the Drive group to be installed. This is only a temporary solution.If the stiffening Rib of the Accumulator plate is modified, the accumulator should be relocated as soon as possible. Modifying the Rib of the Plate may result in more vibration of the accumulator which could cause internal failure of the accumulator.
NOTE: NOTE D: IT38G and 938G equipped with the Standard 55-amp Alternator use the new Alternator Pulley and V-Belt Set listed in the parts list; and also use the new adjustment strap, spacer, bolt, and washer to avoid interference of the new Drive Group Pulley. The IT38G and 938G machines equipped with the Attachment 70-amp Alternator use the same new Alternator Pulley and V-Belt Set as the 950G, 962G and IT62G machines. This is because the Standard 55-amp Alternator used on IT38G and 938G machines has a smaller diameter alternator shaft for the pulley, compared to the attachment 70-amp Alternator. Be sure to determine which alternator (standard 55-amp, or attachment 70-amp) is used on IT38G-938G machines before beginning the update, to determine which alternator pulley and v-belt set are needed. IT38G-938G with 70-amp Alternator is shown on the MSO and in PIS as one of the following Attachments:
NOTE: NOTE D: Some 950G-962G-IT62G machines are equipped with the Attachment Axle Oil Cooler Group (See attached list). Machines equipped with this Attachment already have the correct new crankshaft pulley with 3-grooves to drive the axle oil cooler pump, and the new crankshaft pulley and bolts are not needed. However, these machines must have the position of the axle oil cooler pump changed, by installing the new 166-4869 Bracket for the axle oil cooler pump. Also, while installing the new Bracket, these same machines are eligible to have a new 152-5409 Clutch installed on the pump for the axle oil cooler. The Attachment axle oil cooler pump (if equipped) is located below the crankshaft pulley. The new Bracket moves the axle oil cooler pump closer to the engine. After installation of the new Bracket and Clutch, the same 9L2248 Belt is used to drive the pump. After the Update, the belt is driven from the pulley groove nearest the engine (inside groove). Before installing this Belt Drive Update, determine if the machine is equipped with the Attachment Axle Oil Cooler. The 950G-962G-IT62G machines with axle oil coolers installed at the factory can be identified by one of the following Attachment numbers shown on the MSO or in PIS. A list of machines equipped with the Axle Oil Cooler from the factory is also attached:
- 151-6291 Axle Oil Cooler Group
- or
- 162-6403 with Sound Suppression* (includes Axle Oil Cooler)
- or
- 164-6484 with Sound Suppression* and Air Conditoning (includes Axle Oil Cooler)
- or
- 2Q8096 Kit for dealer-installed Axle Oil Cooler
- or
*Sound Suppression is not the same as Low Sound (LS) Attachment
Rework Procedure
(For Belt Drive Update)
Earlier 938G-IT38G machines equipped with Air Conditioning must must have the A/C Accumulator moved to a new location, before applying this Belt Drive Update. Refer to PS4798, "PSP For Relocating The Air Conditioner Accumulator On Certain 938G Wheel Loaders". Also refer to Note B and Illustrations.
This Belt Drive Update is not adaptable to "Low Sound" (LS) machines, or to 938G machines with the Waste Handler conversion. See Note A.
Painting of New Parts is recommended for rust protection and appearance. Refer to Step 10.
1. 938G-IT38G Before ordering new alternator pulley, v-belt set and adjustment strap parts, first determine if machine is equipped with standard 55-amp alternator, or attachment 70-amp alternator. Refer to Note C.
2. 950G, 962G, IT62G Before ordering parts, first determine if machine is equipped with attachment Axle Oil Cooler Group. Refer to Note D and attached list.
3. Remove alternator pulley and belts for alternator and air conditioner compressor. Use a 5/16-inch Allen-Wrench to hold the alternator shaft, when removing the nut.
4. Remove crankshaft pulley and vibration damper, and discard bolts. Do not remove crankshaft pulley, if equipped with axle oil cooler attachment. Refer to Note D.
5. Install new 4P2843 crankshaft pulley and original damper, using new 6V5230 Bolts listed. Use the 6V1819 Bolt (with bolt head cut off) as a guide pin to hold the new pulley and damper in position during assembly. Remove the 6V1819 Bolt (guide pin), and use it as a guide pin during Step 7 (installation of the new Drive Group and lifting eye).
NOTE: The new crankshaft pulley and bolts are not needed if the machine is equipped with axle oil cooler attachment (Note D). Instead, remove cooler pump and Bracket located below crankshaft pulley. Install new Clutch on Pump. Install new Bracket for pump. Install original 9L2248 Belt for cooler pump on first groove of the crankshaft pulley, closest to engine.
Refer to "Procedure for Replacement of Clutch for Axle Oil Cooler Pump". Removal of the crankcase guard (belly guard) under the engine is needed (if equipped).
6. Remove bolts for engine lifting eye, and discard bolts and washers.
7. Install new 7C8365 Drive Group and original lifting eye with new longer 6V4249 Bolts. Washers are not needed. The new multi-position Drive Group must be installed at the correct height of 447mm above the centerline of the crankshaft for belts to fit properly. Refer to the Illustrations. For "earlier" 938G-IT38G, the tall lifting-eye Plate Assembly for the A/C accumulator must be replaced by a 4W1683 standard lifting eye. The 4W1683 lifting eye is part of PS4798, PSP For Relocating the A/C Accumulator. Refer to Note B and Illustrations.
8. Install new 7C2515 Pulley to new Drive Group, using 8T4908 Bolts. Temporarily install the two (2) 8T0100 Bolts in the small outer flange of the Drive Group to stop rotation of the drive group hub, when tightening the bolts for the new Pulley. Remove the two (2) 8T0100 Bolts from the Drive Group after the new pulley bolts have been tightened.
9. Install new Pulley for alternator. For 938G-IT38G, the correct new pulley part number depends on which alternator is used (Note C). Torque nut to specification. For 938G-IT38G with standard 55 Amp alternator, Install the new adjustment strap, spacer, bolt, and washer.
- 50 ± 5 N·m for 55-amp alt, Standard for IT38G-938G.
- 102 ± 5 N·m for 70-amp alt, Attachment for IT38G-938G, refer to Note C.
- 102 ± 7 N·m for 70-amp Alternator for 950G-962G-IT62G
- 102 ± 5 N·m for 70-amp alt, Attachment for IT38G-938G, refer to Note C.
10. For appearance and rust protection, painting of all unpainted parts prior to installing new belts is recommended. Avoid excessive paint in pulley grooves. Technician may prefer to paint parts prior to installation on machine. Do not paint surfaces of bolted joints prior to assembly.
11. Install the new 1P4334 V-Belt for Air Conditioning (if equipped). This belt is from the new drive group pulley to the refrigerant compressor. Use the pulley groove nearest to the engine.
12. Install V-Belt Set (2-belts) for Alternator. For 938G-IT38G, the correct new V-Belt Set part number depends on which alternator is used (Note C).
13. Tighten all belts and adjustment bolts, including axle oil cooler pump belt (if equipped).
14. Start machine and observe belts for proper operation and alignment. Allow machine to run for 5 to 10 minutes, and shut off engine.
15. Re-check belt tension.
16. Re-check torque of nut for alternator pulley, and other bolts.
17. Inform the Customer of the correct new Belt part numbers for the alternator and air conditioner belts. Use an indelible marker to write the new belt part numbers near the alternator and A/C compressor for future reference. If Customer copy of the machine Parts Manual is available, make a note of the new belt p/n's.
For SIMS reports, use following reporting method:
Part No. PS4774, and Group No. 7751, with Description Code "T"
Enter "Comment": Update Belt Drive
Illustrations
Illustration 1.
Illustration 2.
Illustration 3.
Illustration 4.
Procedure For Replacement Of Clutch For Axle Oil Cooler Pump
(If Equipped)
1. Remove the crankcase guard under the engine (belly guard), if equipped, following Service Manual procedures. The pump is located directly below the crankshaft pulley and damper.
2. Disconnect the electrical harness from the pump clutch.
NOTE: For replacement of the Clutch, the technician may prefer to disconnect the 4 hoses from the pump, so that pump can be completely removed from the machine for clutch replacement. If hoses are disconnected, be sure to put identification marks on each hose for correct installation. Plug all lines and hoses to prevent contamination from entering the system, and to prevent fluid loss. When hoses are disconnected, be prepared to collect the fluid with a suitable container. Dispose of all fluids properly.
NOTE: Technician may prefer to replace the clutch without disconnecting the hoses from the pump to avoid fluid loss. In this case, the clutch replacement must be performed under the machine.
3. Remove the two bolts (A) which hold the pump and adjustment straps to the large mounting Bracket. Refer to Illustration for Axle Oil Cooler Pump and Bracket.
4. Remove the original Bracket for the pump. Install pump on new Bracket.
5. Removal & Installation of Clutch for axle oil cooler pump.
- - Disconnect the electrical connection on the field coil.
- - Remove the shaft nut & lockwasher with a 13mm socket wrench and spanner wrench.
- - Remove the Hub/Armature from the clutch assembly.
- - Remove the shims from the hub/armature and shaft.
- - Replace the original clutch with the new 152-5409 ClutchAssembly.
- - The new clutch should should come partially assembled.
- - Install the rotor/pulley/field coil assembly (Field Rotor Assembly) on the pump shaft.
- - Align the hub keyway with the shaft key and slide the hub/armature onto the pump shaft.
- - Set the rotor/pulley to hub/armature air gap (clearance) at 0.020 to 0.040 inches (0.50 to 1.02mm) by adding or removing shims. Measure using a feeler gauge at 3 locations 120 degrees apart.
- - Install the lockwasher and shaft nut. Torque to 155 lb.in. (17.5 N·m) using a torque wrench and spanner wrench.
- - Remove the shaft nut & lockwasher with a 13mm socket wrench and spanner wrench.
6. Install Bracket & Pump assembly on engine.
7. Install and tighten original 9L2248 Belt for pump. Install belt for pump on pulley groove closest to the engine. Two outer grooves of crankshaft pulley are for the alternator belt set.
8. Install hoses to axle oil cooler pump, if previously removed. Secure hoses properly to prevent rubbing.
9. Attach electrical harness connection to cooler pump.
10. Install crankcase guard (if equipped).
List Of Axle Oil Cooler Machines
Machines Equipped with Axle Oil Cooler (Attachment)
The following is a list of Affected Product s/n's shipped from the factory with the Attachment Axle Oil Cooler Group. When performing this Belt Drive Update, these machines will need the new Bracket and new Clutch for the axle oil cooler pump. However, the new crankshaft pulley and bolts are not needed. Refer to Note D.
