PRODUCT SUPPORT PROGRAM FOR INSPECTING AND REPAIRING ADAPTORS ON CERTAIN 3516 AND 3516B ENGINES

Usage:

SEBE9053

February 7, 2005
U-34
A-24
D-29
O-31

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*before or* *after failure*	PRODUCT SUPPORT PROGRAM FOR INSPECTING AND REPAIRING ADAPTORS ON CERTAIN 3516 AND 3516B ENGINES
1404		PS41639

NOTE: This Program can be administered either before or after failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS41639" 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: 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.

TERMINATION DATE

February 28, 2007

PROBLEM

The SR4B single bearing 825 and 824 frame generators may develop cracks in the air exit window adapter assembly. This is the welded assembly on the front of the generator stator, consisting of the front adapter ring that bolts to the engine flywheel housing and the individual support bars welded to this adapter ring and the generator stator body. Several different modes for the weld failures of the generator adapter may exist:

Cracks along the throat of the weld between the adapter support bars and the front adapter ring. See Illustration 1 for a typical detail.

Illustration 1

Cracks at the toe of the welds joining the adapter support bars to the front and end rings. The cracks appear in the heat-affected zone of the welds and propagate into the associated ring of the generator. See Illustration 2 for a typical detail.

Illustration 2

Circumferential cracks between the end ring (this is the ring welded to the stator body) of the generator adapter and the stator housing. This type of crack most likely occurs after some of the support welds have failed. See Illustration 3.

Illustration 3

AFFECTED PRODUCT

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Model	Identification Number
3516	25Z6904, 6945-6947, 6972, 6980-6986, 7020-7022, 7026, 7036-7037, 7040, 7042-7043, 7049, 7051, 7057, 7059-7061 5SJ716 CMD155-156, 168-177, 183-193, 196-198, 231, 257-258
3516B	7RN1026, 1071-1072, 1749, 1778, 1780-1781, 1803-1812, 1824-1828, 1831, 1856, 1860, 1871-1873, 1875, 1879, 1883, 1897-1898, 1900-1907 FDN176, 196-197, 201-207, 210, 214-215, 217, 224-225, 256, 392-397, 399, 402, 404, 434-440, 442-444, 456, 458, 465, 475, 505, 558, 570, 577-582, 586-587, 590-592, 594-596, 603-626, 648, 682, 703, 707-713, 724-726, 748-753, 761, 767, 770, 775, 798, 801, 840, 870-873, 897-898, 912, 979, 995-996
PM3516	BPD163, 165-232, 234-236, 238-290, 292-307, 310-325, 327, 333-334, 336, 338-367, 369-374, 376-410, 412-418, 420-463, 465-475, 477-508, 510, 512-518, 536-550, 552-568, 570-589, 591-651, 653-654, 656-662, 664-670, 673-675, 677, 679-689, 691, 693-714, 716, 718-766, 768-813, 815-817, 819-822, 826-890, 892-893, 895-899, 901-917, 919-952, 954-959, 961-964, 966-979, 981-998, 1001, 1009-1013, 1015-1025, 1052 CAC364-371 BPD520-534

PARTS NEEDED

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Qty	Part Number	Description
4	8T8911	BOLT
1	2352276	ADAPTER
1	2352277	ADAPTER

ACTION REQUIRED

See the attached Rework Procedure.

SERVICE CLAIM ALLOWANCES

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Product age	Caterpillar		Dealer Suggested		Customer Suggested
	Parts	Labor Hrs	Parts	Labor Hrs	Parts	Labor Hrs
0-84 mos	100%	24.0	0	0	0	0
NOTE: This is a 24.0?hr job. Severity 1 and 2 repairs only.
NOTE: This is a 16.0?hr job for a Severity 3 repair.
NOTE: This is at most an 8.0?hr job for a Severity 4 repair.

PARTS DISPOSITION

Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.

SPECIAL TOOLS NEEDED

Portable welding machine (MIG welder); back gauging equipment (for cracked weld repair); Non-combustible protective material to prevent splatter into the generator stator and rotor windings; power grinder; power wire brush or paint stripping wheel, C-clamps (quantity of 4 or more); and spray on dye-pen crack detector.

Attach. (1-Rework Procedure)
(2-Record Sheet and Crack Severity Matrix)

Rework Procedure

Turn off all supply power, prevent the engine from starting and lock out the equipment before working on or inside the equipment. Only qualified electrical personnel should service this equipment. Replace all devices, doors and covers before turning power on to this equipment. Restore all power when complete. Observe and follow all safety procedures as described in Caterpillar Inc. Manuals. NOTE: Whether a crack is found or not, perform both the inspection AND the repair. Please plan accordingly.

Inspection:

It is necessary to fill out the attached Record Sheet to properly determine extent of the repair. For consultation with the factory, contact the Dealer Solution Network (DSN). NOTE: Spray on dye-pen crack detector may be needed in addition to standard tools. Use a digital camera for pictures.

Remove the generator air exit window drip shield and adapter guard cover to gain access and inspect the generator adapter housing.
Visually inspect each bar for weld cracks in the area where the bar attaches to the adapter ring (bolted to the engine flywheel). Look at both fillet welds on the side of the bar, and the V-weld on the top of the bar. See the attached Illustrations 1?3 for typical weld cracks.
When necessary, carefully scrape the paint and generator varnish to avoid mistaking for cracks in paint, and confirm that the weld is indeed cracked. When in doubt, and when practical, apply a spray on dye-pen or similar product to confirm the crack exists.
Continue and inspect all accessible bars. Access to the bars 7 and 8 (at the bottom of the adapter) is limited and these do not need to be inspected. Document any cracked bars in the Record Sheet.
For all cracks in severity level 1 and 2, or upon request from the factory, take a picture of the most severe crack (digital pictures are preferred) at each installation.
Inspect the welds on the other end of the bar which is welded to the generator end ring (welds at the generator stator), and document these in the Record Sheet.
Complete the Severity matrix, and fax the forms with severity rankings of 1, 2, or 3 to 770-233-3941. Perform the repair procedure described below.

Repair: NOTE: Do not decouple the generator from the engine flywheel housing at any point during the welding process. To prevent possible warping, the equipment shall serve as a heat sink. Observe and monitor the flywheel housing and adapter surface temperature. Stop the welding process and allow the components to cool off if the temperature in the immediate area (no more than 2" from the weld) exceeds 200 F. NOTE: Verify alignment before installing sleeves and correct if necessary. When welding on the engine or near the engine, be sure to protect the engine electronics from spikes in the voltage. The engine block and the driven equipment should be properly grounded. This will prevent any electrical discharge across the main bearings. Proper welding procedures are necessary to avoid damage to the electronic control module and associated sensors and components. The guidelines listed should be followed when welding on any engine or for any application that uses electronic controls:

Stop the engine. Put the ECS switch in the "Off/Reset" position.
Disconnect the ECM connectors at J1 and J2 and the EMCP from the main engine harness connector.
Disconnect the negative (B-) battery cable at the battery, the B(-) cable at the starter motor pinion solenoid and the B(-) cable at the power distribution box. If a battery disconnect switch is provided, place the switch in the OPEN position.
Disconnect all Ground Potential conductors at the starter motor pinion solenoid and the power distribution box.
Connect the clamp for the ground cable of the welder directly to the part. Place this clamp as close as possible to the weld in order to reduce the possibility of damage by the welding current. Do not use fuel system components for grounding the welder.
Protect components that can be easily damaged include bearings, hydraulic components, and electrical components.
Use standard welding procedures in order to weld the materials.

Remove the generator air exit window drip shield and adapter guard if reinstalled after the inspection. Remove the J/W heaters and secure the heaters away from the area, but do not disconnect the J/W heater hoses. Remove the oil sump pump if existing. Clean painted surfaces to be welded, use paint stripping wheel, or other suitable tools.
Grind all cracked welds on the bars. Prepare the cracks for a repair and to apply at least 3/8" fillet size weld. If practical or preferred, carefully back-gouge the weld. Protect the generator stator windings and all other components from the debris and splatter during this operation. Make sure the welding ground cable is properly attached to the generator, near the area to be welded. Follow welding procedures per RENR4700 and SEBD0512.
Reweld all cracked bars. Do not overheat the welded area. Stop the welding process and allow the components to cool off if the temperature in the immediate area (no more than 2" from the weld) exceeds 200 degrees F.
Grind the top of the bars flat (applicable mainly to the re-welded bars).
Install the field weld-on sleeve over the adapter air exit window.
Inspect the sleeve first and identify the side with the bevel.
Place the adapter sleeve over the generator adapter with the beveled side towards the generator stator.
Slide the bottom half of the adapter sleeve over the adapter assembly. This half of the sleeve does not have any slots cut out for the drip shield hardware.
Rotate the sleeve around the adapter to cover the bottom half of the adapter. Position it and align the split horizontally (the split is at 9 and 3 o'clock).
Push the sleeve all the way to the rear until the beveled side is against the stator ring. The front edge of the sleeve should be approximately in the middle of the front ring. See Illustration 4.

Illustration 4

Use suitable C-clamps, or grip clamps to achieve a tight fit around the adapter perimeter. Tack-weld the sleeve in position. Tack at both front and rear of the sleeve, applying 3/16" fillet welds, each approximately 1" long, at the 4 and 8 o'clock area.
Slide the top half of the sleeve over the adapter. This is the half of the sleeve that has slots cut out for the drip shield hardware. Position the sleeve so the hardware cutouts reveal the threaded holes in the adapter bars. Use suitable clamps to assure a tight fit of the sleeve around the adapter perimeter.
Inspect the location of the top and bottom sleeve halves. A properly installed sleeve should have the split at 3 and 9 o'clock, and the gap between the top and bottom half in these locations should be about ¼".
Apply a skip weld at the both front and rear edge of the sleeve.
Apply a 3/16" - 2" long fillet weld on the engine side of the adapter and a ¼" V-weld on the generator stator side.
Apply two passes to achieve a complete ¼" V-weld. Start at the top of the adapter.
Place the welds between the bars and alternate front and rear of the sleeve. Continue as far as accessible, but no less than 30 degrees below horizontal axis (approximately 4 o'clock position). Then, repeat for the left side.
Stop the process and allow the components to cool if the temperature in the immediate area (no more than 2" from the weld) exceeds 200 F.
Next, apply a continuous 3/16" fillet weld at the bar area. Start the weld 2" above the bar and stop 2" below the bar in one pass.
Alternate front and rear of the sleeve. Monitor the surface temperature as above. The sleeve near the bars 7 and 8 does not need to be welded.
Fill in and skips in the weld. When finished the adapter sleeve should have a continuous weld bead from 30 degrees below horizontal axis on the left side (8 o'clock position) to the 30 degrees below horizontal on the right side (4 o'clock position) in the both rear and the front edge of the adapter sleeve.
Use a grinder to clean any splatter on the sleeve, or any weld irregularities, so the fan guard can fit properly.
Wire brush any burned paint. Touch up paint the sleeve and the adapter welds.
Check the generator alignment per SEHS7259.
Install the fan guard screen. Use longer adapter screen bolts (p/n 8T8911)
Install drip shield, and any other components removed for this rework.

Record Sheet and Crack Severity Matrix

Generator adapter inspection

Dealer:___________________ Customer:______________________

Date:___________

Typical Load:________________ kW Application:_________________

S/N:_________________

Engine Hours:_________

Dealer contact:____________________ Phone:________________

Bar position and Score Matrix (See evaluation and legend for instructions).

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Bar welds at the front adapter ring						Welds at the stator (rear) end ring
Bar position	One side of toe weld	Both sides of toe weld	Cracked Ring less than 1.5" long	Cracked Ring more than 1.5" long	Cracked Throat of the bar weld	One side of toe weld	Both sides of toe weld	Cracked Throat of the bar weld	Cracked into stator (rear) Ring	Circum-ferential crack
1	1	1	2	22	2	1	1	2	22	2
2	1	1	2	22	2	1	1	2	22	2
3	1	1	2	22	2	1	1	2	22	2
4	1	1	2	22	2	1	1	2	22	2
5	1	1	2	22	2	1	1	2	22	2
6	1	1	2	22	2	1	1	2	22	2
7	1	1	2	22	2	1	1	2	22	2
8	1	1	2	22	2	1	1	2	22	2
									Total:

Evaluation:

Circle the number in the box corresponding to the bar position and the crack description that applies.

NOTE: It is possible to have multiple numbers circled for each bar position.

Add circled numbers together, insert total in matrix, and interpret the crack severity:

Severity Level 4: (0 points) No cracks found

Severity Level 3: Up to 10 points total

Severity Level 2: Up to 20 points total

Severity Level 1: Above 21 points total

Legend (Refer to Figure A):

Bar position (viewed from generator end toward engine): 1-8 o'clock, 2-10 o'clock, 3-11 o'clock, 4-1 o'clock, 5-2 o'clock, 6-4 o'clock, 7-5 o'clock, 8-7 o'clock.