LI4618E

INFORMATION LETTER
REFERENCE:

Nova Bus Manuals

SECTION:

01: Structure

RS NO:

MQR 7621-1188

SUBJECT:

Transverse box beam located behind the front axle.

JUSTIFICATION:

Repair procedure of the front box beam.

LEVEL

APPLICATION DEADLINE:N/A

DIRECT CHARGES

DESCRIPTION

1

Weld reinforcements on the front transverse box beam.

2

–

TIME

LABOUR

MATERIAL

Client

Client

6h

–

–

–

MATERIAL
QTY

PART NO

REV.

DESCRIPTION

REPLACES PART N°

1

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

N96100-061170

–

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 1

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.

DISPOSAL OF PARTS
REMOVED PARTS ARE:

DISCARDED *

RETAINED

Yes

–

* Dispose of the unused parts and the defective parts in
accordance with local environmental standards in effect.

REVISION HISTORY
REV.

DATE

NR

2019JU04

APPROVED BY:

CHANGE DESCRIPTION

Initial release

Daniel Theriault

NQF772002 VERSION 3

WRITTEN BY

André Pelletier
Digitally signed by Daniel Theriault
DN: cn=Daniel Theriault, o=Nova Bus, ou, email=daniel.theriault@volvo.com, c=CA
Date: 2019.06.10 21:23:46 -04'00'

PAGE 1 OF 10

INFORMATION LETTER
CLIENT

ORDER

ROAD NUMBER

LI4618E

VIN (2NVY/4RKY...)

FROM

TO

FROM

TO

QTY

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

PAGE 2 OF 10

NQF772002 VERSION 3

INFORMATION LETTER

LI4618E

WARNING

FOLLOW YOUR INTERNAL SAFETY PROCEDURES.

PROCEDURE
CAUTION

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.
CAUTION

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.
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.

Box beam

Repair zone

Figure 1 - Repair Zone
PAGE 3 OF 10

NQF772002 VERSION 3

INFORMATION LETTER
1.4.

LI4618E

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.
Left gusset
Right gusset

Threaded studs

Areas to clean

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.

13

2

1/

i

n.

2
1/

.

in

Figure 3 - Chamfer Location (Typical on Both Sides)

PAGE 4 OF 10

NQF772002 VERSION 3

INFORMATION LETTER

LI4618E

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

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.

7,56 in.

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

PAGE 5 OF 10

NQF772002 VERSION 3

LI4618E

INFORMATION LETTER
NOTE

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.
1.11.

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

3

WIRE : 309LSI .045
GAZ : 98% ARGON AND
2% OXYGEN
WELDING PARAMETER :
23V, 350 IPM

6

5

WELDING PROCESS:
GMAW

4

2

1

1/8'' WELD
8

7

9

10

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.

1

2

4

3

Figure 7 - Weld in the Directions Shown

PAGE 6 OF 10

NQF772002 VERSION 3

INFORMATION LETTER
1.13.

LI4618E

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.

19/32 in.

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

PAGE 7 OF 10

NQF772002 VERSION 3

LI4618E

INFORMATION LETTER
1.15.

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

6

5

2

1

4

3

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.

4

3

2

1

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

PAGE 8 OF 10

NQF772002 VERSION 3

INFORMATION LETTER

LI4618E

NOTE

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

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)

PAGE 9 OF 10

NQF772002 VERSION 3

INFORMATION LETTER

LI4618E

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.
NOTE

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.
1.24.

Install mud guards.

1.25.

Lower the vehicle as per your maintenance manual section 18: hoisting and towing.

CAUTION

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

1.26.

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

PAGE 10 OF 10

NQF772002 VERSION 3