NQF772002 VERSION 3

REFERENCE: Nova Bus ManualsSECTION: 01: StructureRS NO: MQR 7621-1188

MATERIALQTY PART NO REV. DESCRIPTION REPLACES PART N°

LEVEL 11 N87853-1 A Front Left Box beam reinforcement, STN STL SH - UNS

S41003 (ASTM A 240) 12 GA. (2.778 mm) THK–

1 N87853-2 A Front Right Box beam reinforcement, STN STL SH - UNS S41003 (ASTM A 240) 12 GA. (2.778 mm) THK

–

2 N96100-06-1170

– Gusset (23035606) –

50 ml N10844 – Sika 205 Aktivator –1 liter N71300 – Tectyl 3344 –50 ml N21161 – Sika 206 G+P –

200 ml N79106 – Sikaflex 221 –LEVEL 2

– – – – –To order, please contact Prevost Parts by phone at 1-800-771-6682, by fax at 1-888-668-2555 or by email at prevostparts.commandes@volvo.com. Specify document number, quantity of parts required and shipping address.

LEVEL DESCRIPTIONDIRECT CHARGES

TIMELABOUR MATERIAL

1 Weld reinforcements on the front transverse box beam. Client Client 6h2 – – – –

SUBJECT: Transverse box beam located behind the front axle.JUSTIFICATION: Repair procedure of the front box beam.

REVISION HISTORYREV. DATE CHANGE DESCRIPTION WRITTEN BY

NR 2019JU04 Initial release André Pelletier

DISPOSAL OF PARTS

REMOVED PARTS ARE:DISCARDED * RETAINED * Dispose of the unused parts and the defective parts in

accordance with local environmental standards in effect.Yes –

APPROVED BY:

APPLICATION DEADLINE:N/A

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CLIENT ORDERROAD NUMBER VIN (2NVY/4RKY...)

QTYFROM TO FROM TO

New York City Transit - New York L608 8000 8014 L82U6B4000047 L82U0B4000061 15

New York City Transit - New York L620 8015 8074 L82U2B4000062 L82U7B4000123 60

New York City Transit - New York L621 8075 8089 L82U9B4000124 L82U9B4000138 15

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NQF772002 VERSION 3

PROCEDURE

WARNING

FOLLOW YOUR INTERNAL SAFETY PROCEDURES.

Microprocessor based control modules are extremely sensitive to voltage surges, such as those that can occur during electric-arc welding, or plasma cutting of any kind, anywhere on the vehicle. Before attempting any electric-arc welding, or plasma cutting, qualified personnal has to disconnect both 12 and 24 volt power at the battery and all control modules to prevent damage to their components as per maintenance manual section 01: Structure.

For information on hoisting and towing of the vehicle, see section 18: hoisting and towing in the Nova Bus maintenance manual. Use appropriate hoisting equipment for your protection and to prevent damage to the vehicle.

CAUTION

CAUTION

1.1. Raise the vehicle.1.2. Before performing the procedure for repairing the box beam, do the repair required by LI1841E.1.3. Adjacent surfaces and parts should be moved and suitably protected (by using proper fire blocker blankets,

etc.) to prevent damage.

Repair zone

Box beam

Figure 1 - Repair Zone

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1.4. Clean both areas by removing the original Tectyl 3344 undercoating compound with a putty knife. Cleaned areas must be prepared to weld new parts, the areas must extend to about 100 mm (4 in.) beyond the size of N87853 reinforcement.

Figure 2 - Remove Parts and Clean the Surfaces

1.5. Remove and discard the gussets and the four threaded studs shown. Take care not to damage the structure by grinding flush with the surfaces. See Figure 2.

1.6. Make a chamfer to allow a perfect support between the box beam and the new reinforcements. See Figures 3 and 4.

Areas to clean

Threaded studsRight gusset

Left gusset

Figure 3 - Chamfer Location (Typical on Both Sides)

13 1/

2 in. 1/2

in.

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1.7. Drill a stop-hole of 1/8 in. diameter at each end of the crack and grind out to the root of the crack.1.8. Start the repair weld at one of the stop-holes and continue to the midpoint of the crack. Then start at the other

end and again work toward the midpoint. If the crack stops at the edge of the part, the weld should begin at the stop-hole and continue right to the edge of the cracked part. See Figure 6 for the welding process.

1.9. Grind the weld flush with the surface for a proper installation of N87853 reinforcement.1.10. Install a reinforcement making sure to position the threaded stud in the right place for the fender. See Figure 5.

New reinforcement N87853

No space allowed

Make a chamfer to get a perfect support

No space allowed

Figure 4 - Sectional View of the New Reinforcement and Box Beam

Figure 5 - N87853 Reinforcement Position (Typical for Both Sides)

7,56 in.

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Repairs must be performed by qualified welders in accordance with approved welding procedures, AWS D8.8-89 or SAE HS J1196. For more information on the welding process and specifications, see section 01: Structure of your service manual.

NOTE

1.11. Protect threaded studs and all components from weld spatter, heat, and flames. Make spot welds in the order shown on Figure 6.

1

4

6

7 8

2

109

3

5

Figure 6 - Make Spot Welds

1.12. In order to dissipate the heat, make a full weld in several beads of approximately 2 in., follow the directions shown in Figure 7. Make a bead weld in one of the four zones then in another to space the beads as much as possible.

12

34

Figure 7 - Weld in the Directions Shown

WELDING PROCESS: GMAW

WIRE : 309LSI .045

GAZ : 98% ARGON AND 2% OXYGEN

WELDING PARAMETER : 23V, 350 IPM

1/8'' WELD

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1.13. Weld the oblong hole as shown in Figure 8. Repeat for the other holes.

Figure 8 - Weld the Oblong Hole as Shown (typical on Both Sides)

1.14. Position the gussets at 19/32 in from the edge of the reinforcement.

Figure 9 - Position the Gussets (Typical for Both Sides)

19/32 in.

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1.15. Make the spot welds for the gussets as shown in Figure 10.

12

34

56

Figure 10 - Gussets Welding Spots Sequence (Typical for Both Sides)

1.16. Make the gusset weld beads as shown in Figure 11. Make beads of about 2 in. long alternating between areas to dissipate the heat.

12

34

Figure 11 - Directions to Follow for the Welding of the Gussets (Typical for Both Sides)

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1.17. Once cooled, clean the bare metal with a degreaser such as Zep 50 or equivalent.1.18. Brush with a stainless steel brush only.1.19. Do a second cleaning with a degreaser.1.20. Apply Sika Aktivator 205 to the welds. The 205 must dry for 10 minutes. See your Service Manual section

01: Structure for more information on products use.

Figure 12 - Clean and Apply Sika 205 on All Welds (Typical for Both Sides)

Drying time in this document is based on 73°F with 50% relative humidity.

NOTE

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1.21. Apply Sika 206 Primer on the welds. Allow to dry for 10 minutes.1.22. Apply Sikaflex 221 on the welds. Allow 60 minutes to dry.1.23. Apply the undercoating compound Tectyl 3344 N71300 in a thin coat with a sprayer. See the procedure in

section 01: Structure of your service manual for more information. Cover all repaired areas.

Application of Tectyl 3344 must be done in a well-ventilated area, both to ensure good drying and to prevent the accumulation of fuel elements in the air.

NOTE

1.24. Install mud guards.1.25. Lower the vehicle as per your maintenance manual section 18: hoisting and towing.

Ask the qualified personnel to reconnect the proper components per maintenance manual section 01: Structure prior to reconnect the battery.

CAUTION

1.26. The vehicle can go back in service after the minimum drying time for the Tectyl 334 is respected.

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