Top 5 fixes to your LTMV

[TheRealJohnnyB]

Hey guys - I'm working on a new build over here and curious to know what your top 5 fixes would be?

On the 3116, the oil line of death for sure.

Other I would think would include

Secondary trans cooler delete
New battery cables (the corrosion gets bad on these!)
All new front end bushings/steering linkages
New cab air springs is a must for the wife

Next up, balance drive shafts and ecohubs.

 

[Ronmar]

Hey guys - I'm working on a new build over here and curious to know what your top 5 fixes would be?

On the 3116, the oil line of death for sure.

Other I would think would include

Secondary trans cooler delete
New battery cables (the corrosion gets bad on these!)
All new front end bushings/steering linkages
New cab air springs is a must for the wife

Next up, balance drive shafts and ecohubs.

On a 3116 I would(and did) re plumb the engine cooling back to the way cat designed it. As it is now the plumbing sends all the bypass coolant down to the trans cooler instead of back thru the engine to get the engine to proper op temp. Running a diesel too cold is not good for it. As plumbed the engine will not warm up until the transmission becomes a heat source.

Cat originally had the bypass coolant coming out the bottom of the housing and right back into the top of the water pump. they left it the way cat designed it on the 3126 and C7 lMTVs

I ran my heater return line down to the port on top of the cooler, so I can send fluid down there if I wish/when its cold out. the engine now warms right up to op temp. You can modify the existing thermostat housing by cutting the cast elbow off and you will need a cat water pump. This mod also allows you to go back to the cat pump(easilly sourced, there are 2 types) as opposed to the modified one required for the LMTV(not so easy to find) or having to modify one(cut of bypass input pipe and install freeze plug). I did a utube video on this mod under user name rronmar.

 

[wheelspinner]

The air compressor bracket!!!! Make SURE it’s tight and use locktite

 

[GeneralDisorder]

ECO hubs (#1 with a bullet)
Cruise Control
Factory style A1P2 air conditioning
370 HP ECM flash
Gen 1 HIMARS turret hatch.

 

[fuzzytoaster]

From doing several hundred FMTV of all variants, ages, etc..

1. New fuel hoses (there are 3)
2. Rebuild cab lift pump/reseal cab latch
3. Run second ground from 24v (-) direct to chassis
4. Inspect/clock/balance drive shafts
5. Inspect/replace rubber fan bushing if required

Neglecting any of these 5 will eventually lead to a major failure.

 

[GeneralDisorder]

From doing several hundred FMTV of all variants, ages, etc..

1. New fuel hoses (there are 3)
2. Rebuild cab lift pump/reseal cab latch
3. Run second ground from 24v (-) direct to chassis
4. Inspect/clock/balance drive shafts
5. Inspect/replace rubber fan bushing if required

Neglecting any of these 5 will eventually lead to a major failure.

These are all good too. Down to semantics but I would call these preventative maintenance. Fixing to me addresses something that is broken or missing. Fine lines between preventative maintenance, fixes, upgrades, and modifications. They all land on a spectrum somewhere for sure but fuel hoses aren't glamorous so didn't really occur to me to list them in my top since the OP was including ECO hubs and trans cooler delete, etc.

Another BIG one that gets neglected - air dryer service.

 

[olly hondro]

Bypass the reverse polarity box. Gain 0.7 volts diode drop, lose a common corrosion location.

Delete one of the two series battery strings. Running two batteries is easier on the goofy dual voltage alternator. The exception would be for large electrical load application, such as a shelter, obnoxious off road light suite, or heavy winching.

 

[Awesomeness]

A good readthrough here in the Common Problems-Fixes document in my signature.

 

[olly hondro]

Front gladhand delete. Nearly every "How come my brakes don't work right?" problem traces back to one of the three pneumatic valves that support front glad hand functionality.

 

[Awesomeness]

Front gladhand delete. Nearly every "How come my brakes don't work right?" problem traces back to one of the three pneumatic valves that support front glad hand functionality.

Preventative maintenance on it, or replacing it, would be of similar difficulty, and allow you to keep it.

 

[GeneralDisorder]

Preventative maintenance on it, or replacing it, would be of similar difficulty, and allow you to keep it.

Agree. Wouldn't delete them. We have a good community/network of FMTV and other military vehicles throughout the country on this forum and the facebook groups, etc and some of us have tow bars, air hoses, and interconnect cables that can allow us to rescue or be rescued. Not having the front glad hands would make that needlessly harder.

Yes there are several one way and two way check valves that should be replaced once every two decades.

I wouldn't delete any of the glad hands or the NATO slave receptacle.

 

[fuzzytoaster]

These are all good too. Down to semantics but I would call these preventative maintenance. Fixing to me addresses something that is broken or missing. Fine lines between preventative maintenance, fixes, upgrades, and modifications. They all land on a spectrum somewhere for sure but fuel hoses aren't glamorous so didn't really occur to me to list them in my top since the OP was including ECO hubs and trans cooler delete, etc.

Another BIG one that gets neglected - air dryer service.

I agree they are or should be preventative but by the time we get them it's mandatory. *cough* I mean the Army totally follows all PMCS by the TM of course! *cough*

 

[TheRealJohnnyB]

On a 3116 I would(and did) re plumb the engine cooling back to the way cat designed it. As it is now the plumbing sends all the bypass coolant down to the trans cooler instead of back thru the engine to get the engine to proper op temp. Running a diesel too cold is not good for it. As plumbed the engine will not warm up until the transmission becomes a heat source.

Cat originally had the bypass coolant coming out the bottom of the housing and right back into the top of the water pump. they left it the way cat designed it on the 3126 and C7 lMTVs

I ran my heater return line down to the port on top of the cooler, so I can send fluid down there if I wish/when its cold out. the engine now warms right up to op temp. You can modify the existing thermostat housing by cutting the cast elbow off and you will need a cat water pump. This mod also allows you to go back to the cat pump(easilly sourced, there are 2 types) as opposed to the modified one required for the LMTV(not so easy to find) or having to modify one(cut of bypass input pipe and install freeze plug). I did a utube video on this mod under user name rronmar.

Awesome channel -Thanks for sharing! Cat pump is a must.

Love the cab lift setup btw, totally steeling that! Cheers

 

[olly hondro]

Delete the hydraulic kneeling circuit. I understand some of us still load their FMTV onto C130s so need it, but for the rest of us it is useless complexity.

I considered splitting the circuit then using the cylinders as suck down winches, but got over it.

 

[Awesomeness]

Delete the hydraulic kneeling circuit. I understand some of us still load their FMTV onto C130s so need it, but for the rest of us it is useless complexity.

I considered splitting the circuit then using the cylinders as suck down winches, but got over it.

The kneeling hydraulic cylinders could be repurposed/replaced with cylinders to do something else useful, such as extend an awning, deploy stairs, or lift a fuel can rack.