DEPARTMENT OF THE NAVY

HEADQUARTERS, UNITED STATES MARINE CORPS

WASHINGTON, DC 20380-0001

PCN: 161 840003 00

NORMAL

MI 8400-OR/3

31 MAR 2011

U.S. MARINE CORPS MODIFICATION INSTRUCTION

INSTALLATION OF THE A2 THERMAL SHROUD ASSEMBLY KIT ON

THE FAMILY OF LIGHT ARMORED VEHICLES

1. Purpose.

2.

This Modification Instruction (MI) provides instructions for installing the LAV A2 Thermal Shroud Assembly Kit on the Family of Light Armored Vehicles (FOLAV) with the LAV A2 (short) muffler.

Applicability.

3.

This modification applies to all LAV A2 variants and serial numbers with the (short) muffler.

Time Compliance Period.

4.

This MI will be completed one year from issuance.

Information.

The eductor, item (1) is not part of the Thermal Shroud Assembly Kit and must be obtained separately for installation with the kit.

The Thermal Shroud Assembly Kit is designed to shroud the upgraded, A2 muffler configuration to reduce the thermal signature of the vehicle. It can be installed on vehicles with or without the Ballistic Protection Upgrade Package (BPUP). The Muffler Adapter Upgrade Kit MI-8400-OD/41 must be installed on vehicles which still have the original muffler adapter. The new muffler adapter significantly reduces the possibility of exhaust leaks which can damage the composite armor and the thermal shroud.

A few Thermal Shroud Assembly Kits contain thermal shrouds, (item 2), that are not compatible with the LAV-25A1/A2 variants. Inspect the inside wall of the thermal shroud assembly. If a stencil is present that reads "DO NOT USE ON 25", do not use that thermal shroud assembly on LAV-25A1/A2 variants.

5. Technical Manuals Affected. TM 08594C-20/4-LG VOL 2, SL-4-08594C

6.

Description

Major Items Affected

NSN TAMCN I.D. No.

LIGHT ARMORED VEHICLE,

25MM (LAV-25A2)

2355-01-539-3639 E09477M 08594C

LIGHT ARMORED VEHICLE,

Anti-Tank (LAV-ATA2)

2355-01-539-3618 E09427M 08652C

LIGHT ARMORED VEHICLE,

Mortar (LAV-MA2)

2355-01-539-3578 E09497M 08655C

LIGHT ARMORED VEHICLE,

Logistics (LAV-LA2)

2355-01-539-3634 E09487B 08654C

LIGHT ARMORED VEHICLE,

Command and Control (LAV- C2A2)

2355-01-539-3589 E09467B 08650C

LIGHT ARMORED VEHICLE,

Recovery (LAV-RA2)

2355-01-539-3601 E09507B 08651C

MEWSS-A2 2320-01-236-4235 A09667G 09999A

7.

Item

Materiel Required

Description NSN PN QTY

(1) EDUCTOR 4730-01-530-6890 E078-A594-

AX (L6368)

THERMAL SHROUD

ASSEMBLY

INSTALLATION KIT

Consisting Of:

E078-A000-

GX (L6368)

KIT

(2) THERMAL SHROUD

ASSEMBLY

E078-A510-

EX (L6368)

(3) SHROUD SKIRT E078-A520-

CX (L6368)

(4) EDUCTOR BRACKET

EXTENSION

E078-P021-

DX (L6368)

(5) M8 SOCKET HEAD CAP

SCREW, 20 MM

E078-P033-A (L6368)

(6) M8 FLAT WASHER REG.

1.0” O.D

E078-P029-A (L6368)

(7) M8 INTERNAL TOOTH

LOCK WASHER

E078-P032-A (L6368)

(8) M8 HEX NUT E078-P031-A

(L6368)

(9) M8 FLAT WASHER 32 MM

OD x 9 MM ID

E078-P030-A (L6368)

(10) SHROUD SKIRT, TOPSIDE

REAR

E078-A540-

BX (L6368)

(11) SHROUD SKIRT, TOPSIDE

FRONT

E078-A530-

BX(L6368)

(12) COVER, RADIATOR

ACCESS NUT

E078-A570-

AX (L6368)

Item Description NSN PN QTY

(13) WELDMENT, PERSONNEL

HEATER EXHAUST

E078-A514-

CX (L6368)

(14) FLEX TUBE, PERSONNEL

HEATER EXHAUST

E078-P024-

AX (L6368)

(15) BAND CLAMP, FLEX TUBE E078-P403-

AX (L6368)

(16) COVER, BILGE FRONT E078-A560-

BX (L6368)

(17) COVER, BILGE REAR E078-A550-

BX (L6368)

(18) THERMAL JACKET,

MUFFLER

E078-P402-

AX (L6368)

(19) EDUCTOR FLEX TUBE

CONNECTOR

E078-A580-

BX (L6368)

(20) GASKET, MUFFLER

(DURLON)

5330-01-571-6255 03002A5442

(1LZX7)

8. Materiel Discarded

Item

. Dispose of discarded materiel in accordance with current Marine Corps directives.

Description NSN PN QTY

(21) ELBOW, 5 INCH, 90

DEGREE

ZFS89924A 1

(22) 5 INCH TUBING CLAMP EC50PLA 1

(23) GASKET, MUFFLER

(DURLON)

5330-01-571-6255 03002A5442

(1LZX7)

9.

Item

Materiel Retained

Description NSN PN QTY

(24) MUFFLER ASSEMBLY 2990-20-005-9022 E068-A000-BX 1

10. Bulk and Consumable Materiel

Item

Description NSN PN

(25) Thread Locker 8030-01-025-1692 Loctite 242 (F7121)

11. Supply Action.

12.

This Modification Kit will be force fed to units by MARCORPSYSCOM.

Skill and Time Required.

13.

Two LAV Repair Technicians, MOS 2147, approximately 3 hours.

Modification Procedures.

Drill Tools

Putty knife Torque wrench, 0-175 lb-ft Ratchet, 1/2 inch drive 5 inch extension, 1/2 inch drive 3/8 inch drill bit 7/16 inch deep well socket, 1/2 inch drive 1/2 inch deep well socket, 1/2 inch drive 9/16 inch deep well socket, 1/2 inch drive 6 mm Allen wrench 19 mm socket, 1/2 inch drive

MI 8400-OD/41 MUFFLER ADAPTER UPGRADE MUST BE INSTALLED

BEFORE THE THERMAL SHROUD ASSEMBLY KIT IS INSTALLED.

FALURE TO INSTALL THE MUFFLER ADAPTER UPGRADE KIT CAN

RESULT IN HEAT DAMAGE TO THE THERMAL SHROUD ASSEMBLY.

CAUTION

NOTE

Use the vehicle maintenance log(s) to check if MI 8400-OD/41 Muffler Adapter Upgrade has been installed on the vehicle. Another indicator that the Muffler Adapter Upgrade was installed on the vehicle is the presence of two 1/2 inch thick spacers where the muffler assembly top brackets mount to the vehicle (Figure 1).

If the Muffler Adapter Upgrade Kit is installed on the vehicle, proceed to

(a. Muffler Assembly Removal

If the Muffler Adapter Upgrade Kit has not been installed on the vehicle, install the Muffler Adapter Upgrade Kit MI 8400-OD/41. When installing the Muffler Adapter Upgrade Kit, if the vehicle does not have armor plates, disregard all instructions that relate to armor plates. After installation of the Muffler Adapter Upgrade Kit, proceed to (a.

) in this instruction.

Muffler Assembly Removal

) in this instruction.

Figure 1.

a.

(1.) Remove 7 inch V-band clamp securing muffler assembly to adapter using a 1/2 inch drive ratchet and a 1/2 inch deep well socket. Allow clamp to hang loose around adaptor.

Muffler Assembly Removal

(2.) Remove hull-side venturi flex tube band clamp using a 7/16 inch deep well socket, 5 inch ratchet extension and 1/2 inch drive ratchet.

(3.) Remove 2 mounting bolts, washers, and 1/2 inch thick spacers using a 19 mm socket, 5 inch extension, and 1/2 inch drive ratchet. Retain mounting bolts, washers, and spacers for installation later.

(4.) Remove muffler assembly (24) with venturi flex tube and band clamps attached.

(5.) Remove venturi flex tube and band clamps from muffler assembly. Retain venturi flex tube, band clamps and muffler assembly.

b.

(a.) If 90 degree elbow (21) is installed on the muffler assembly, remove elbow and clamp (22) by loosening two bolts and nuts using 9/16 inch deep well socket and 1/2 inch drive ratchet. Discard elbow and clamp.

90-Degree Elbow c.

(1.) Place muffler thermal jacket (18) on a flat surface with opening facing up.

Muffler Thermal Jacket Installation

(2.) Set muffler assembly (24) into muffler thermal jacket (18). Ensure exhaust tube slips through designated holes in muffler thermal jacket (Figures 2 and 3).

Figure 2.

Figure 3.

(3.) Using attached Velcro on muffler thermal jacket (18), secure muffler thermal jacket around muffler assembly (24). Ensure Velcro centerline of thermal jacket is pulled snug to ensure thermal jacket is wrapped tightly around muffler assembly. (Figures 4 and 5).

(4.) Remove and discard muffler gasket (23) (Figure 5).

(5.) Install venturi flex tube with band clamps onto muffler assembly (24) using 7/16 inch deep well socket and 1/2 inch drive ratchet.

Figure 4.

Figure 5.

d.

(1.) Ensure all remaining gasket material has been removed from muffler assembly and muffler adapter flanges. If required, remove remaining gasket material with a putty knife.

Muffler Assembly Installation

(2.) With V-Band clamp loose on muffler adapter. Position muffler assembly with thermal jacket onto muffler assembly mounts.

(3.) While supporting muffler assembly in position, install muffler assembly to hull with 2 bolts, lock washers, and 1/2 inch thick washers (Figure 6). Do not tighten bolts, muffler assembly needs to be loose enough to install gasket between muffler assembly flange and adaptor flange.

Figure 6.

(4.) Position new muffler gasket (20) between muffler assembly (24) flange and muffler adaptor flange.

(5.) Align muffler assembly flange with muffler adaptor flange. Ensure that gasket is centered between muffler assembly flange and muffler adaptor.

If the vehicle has armor, do not allow the wrapper; trunnion or nut on the V-band clamp to come in contact with the armor. If necessary, rotate the V-band clamp to clear the armor, and then tighten the clamp. If any part of the V-band clamp is against the armor when tightened, the V-band clamp will not seat or align properly on the flanges and an exhaust leak will result.

(6.) Maintaining alignment of flanges and gasket, tighten V-Band clamp using 1/2 inch deep well socket and 1/2 inch drive ratchet (Figure 7).

Figure 7

CAUTION

V-BAND WRAPPER, TRUNNION AND

NUT NOT CONTACTING ARMOR

(7.) Install venturi tube with band clamp to hull flange. Tighten band clamp using 7/16 inch deep well socket and 1/2 inch drive ratchet (Figure 8).

Figure 8.

(8.) Tighten muffler assembly mounting bolts to 70 lb-ft (95 N∙m) using 19 mm socket, 5 inch ratchet extension and 1/2 inch drive ratchet.

(9.) Start engine and check muffler assembly and connections for exhaust leaks.

e.

(1.) Align bottom of eductor bracket extension (4) with bottom of eductor (1) (Figure 9).

Eductor and Eductor Flex Tube Connector Installation

(2.) Install eductor bracket extension (4) to eductor (1) with screw (5), lock washer (7), flat washer (6), and nut (8) using a 6 mm Allen wrench (Figure 9).

Figure 9.

(3.) Ensure eductor bracket extension and eductor bottoms are flush. Use existing hole in eductor bracket extension (4) as a template (Figures 10 and 11). Locate, mark and drill a 3/8 inch hole through eductor.

Figure 10.

(4.) Install eductor bracket extension (4) to eductor (1) with screw (5), flat washer (6) lock washer (7) and nut (8) using a 6 mm Allen wrench (Figure 11).

Figure 11.

(5.) Use eductor flex tube connector (19) mounting flange as a template. Position eductor flex tube connector on outside of eductor (1) (Figure 12). Locate and mark hole for drilling.

Remove eductor flex tube connector.

(6.) Drill a 3/8 inch hole through eductor (1) (Figure 12).

Figure 12.

(7.) Position eductor flex tube connector (19) mounting flange inside of eductor (1) (Figure13).

(8.) Attach eductor flex tube connector (19) to eductor (1), with screw (5) and lock washer (7), using a 6 mm Allen wrench (Figure 13).

Figure 13 f.

(1.) Position eductor (1) inlet baffle over muffler assembly (24) exhaust tube (Figure 14).

Personnel Heater Flex Tube Installation

(2.) Attach eductor bracket extension (4) to muffler assembly (24) with two screws (5) and lock washers (7) using a 6mm Allen wrench (Figure 14).

Figure 14

(3.) Attach personnel heater flex tube (14) to personnel heater weldment (13) and eductor flex tube connector (19) with two band clamps (15) using a 7/16 inch deep well socket and 1/2 inch drive ratchet (Figure 15).

Figure 15 g.

Thermal Shroud Installation

The thermal shroud is shipped with parts that have to be removed before the shroud is installed. Retain the parts removed.

A few Thermal Shroud Assembly Kits contain thermal shrouds (item 2) that are not compatible with the LAV-25A1/A2 variants. Inspect the inside wall of the thermal shroud assembly. If a stencil is present that reads "DO NOT USE ON 25", do not use that thermal shroud assembly on LAV-25A1/A2 variants.

(1.) Remove screws (5) and flat washers (6) securing shroud skirt (3), shroud skirt topside rear (10), shroud skirt topside front (11) to shroud using a 6mm Allen wrench (Figure (16). Retain skirts, screws and washers.

(2.) Remove screws (5) and lock washers (7) securing radiator access nut cover (12), front bilge cover (16) and rear bilge cover (17) from shroud using a 6mm Allen wrench (Figure 16). Retain covers, screws and lock washers.

Figure 16.

Before installing thermal shroud, run screws (5) through all four muffler assembly fasteners (weld nuts) to ensure fastener treads are clear of debris.

(3.) Leading with top side of thermal shroud, ensure thermal shroud is outside mounts on muffler assembly and under engine compartment’s safety latch. Slowly lower thermal shroud (2) over muffler assembly (24) and eductor (1). Use bilge port depressions in shroud as visual guides.

(4.) Adjust thermal shroud (2) as necessary to align with mounting holes so that top edge of thermal shroud fits to hull with little or no gaps. Ensure shroud does not get caught on eductor, engine compartment safety latch, or eductor bracket extension. Ensure rubber seal is not pinched or rolled under.

NOTE

• Apply Thread Locker (25) to all of the screws (5) that are used to fasten the thermal shroud and the thermal shroud skirt to the hull.

• Do not tighten screws (5) until all screws have been started and the upper rubber seal of the thermal shroud is pressed against the hull.

(5.) Install thermal shroud to hull with seven screws (5) and washers (6) using 6 mm Allen wrench. Do not tighten screws. Thermal shroud should be loose enough to position top side rubber seal (Figure 17).

(6.) With thermal shroud (2) in position, ensure rubber seal on top of shroud is snug against hull.

(7.) Tighten three screws across top of shroud. Tighten screw that secures thermal shroud to eductor bracket extension first, and then work forward tightening muffler assembly bracket screws (Figure 17).

(8.) Tighten four bottom screws. While tightening bottom screws, ensure thermal shroud is pulled out and away from hull/armor.

(9.) Install shroud skirt (3) across bottom of thermal shroud (2) from rear of shroud forward with nine screws (5) and washers (6) using 6mm Allen wrench (Figure 20). Ensure rubber seal is snug against hull/armor before tightening screws.

(10.) Install front bilge cover (16) and rear bilge cover (17) with four screws (5) and lock washers (7) using 6mm Allen wrench (Figure 17). Rubber seal on rear bilge cover may need to be cut to fit (Figure 18).

(11.) Attach topside front shroud skirt (11) and topside rear shroud skirt (10) on upper rear area of thermal shroud with five screws (5) and washers (6) using 6mm Allen wrench (Figure 17).

Figure 17.

(12.) Install radiator access nut cover (12) onto shroud with two screws (5) and lock washers (7) using 6mm Allen wrench. For proper fit, rubber seal of radiator access nut cover may have to be trimmed to fit around engine compartment safety latch mount (Figures 17 and 18).

Figure 18

(13.) Check thermal shroud fit to armor/hull for any large gaps that a live round could fall through (Figures 19 and 20). Adjust shroud as necessary.

Figure 19

Figure 20

MI 8400-0R/3

Recording and Reporting the Modification. Ensure appropriate records are updated in accordance with the current edition ofTM 4700-15/1 or as set forth in the instruction. Report the application of all FOLA V Modification Instruction and Technicallnfonnation changes to the Configuration Management Mail Box at dami lavcmreporting@conus.army.mil. At a minimum, the following infonnation is required: MI number; MI title; vehicle model (i .e. LA V -25A 1);

vehicle serial number; date of MI installation. This infonnation is required to update the PMO, LA V configuration management database.

BY DIRECTION OF THE COMMANDANT OF THE MARINE CORPS

OFFICIAL ... •• &:

B. K. BUCKLES

Colonel, USMC

Program Manager, Light Annored Vehicles Marine Corps Systems Command

DISTRIBUTION: PCN: 161 84000300 EDO