New MV Owner 1989 LMTV m1079

[LMTV89]

What's up yall! Just got my truck last week, first impressions...

1- I can't believe how easy it is to drive!
2- it's sooooo slow for first 2 gears and 3rd(4th?) feels like I hit the nitro, is that normal?
3- there is air leaking from what I think is the cab mount under the driver's pos above the leaf springs, is that a major problem?
4- the oil was overfull and was spewing out the vent pipe underneath on my 2 hour ride home, it stopped about halfway, going to drain it and refill to spec before I drive again. Hopefully that is OK.
5- it's frigging huge and lots of people waved and smiled while in town.
6- I wanna play with the CTIS and Shift panel but not sure how it works, any tutorials?

Any common issues I should check on?

Odo is 4k miles, is that legit? Like engine and trans is 4k or was everything rebuilt 4k ago? If rebuilt what level of rebuilt we talking.

Looking forward to learning.

 

[NDT]

2. Yes
3. No
5. Because they believe you are active military and they are showing you appreciation. Make sure you represent our military in a positive manner, that is until you paint the truck a non-military color.
6. read the technical manuals, there is a lot to it.

Odo is likely legit, shop vans didn't get a lot of use.

Oh and verify your year of mfg, S&S wasn't building FMTVs in 1989.

 

[Ronmar]

Yep read the manual.

Was that a typo,and you have a 98 1079A0?

With the 2:1 hubs, the first 2 gears(2nd&3rd) are still pretty tall. Lightly loaded it usually bangs thru them pretty quickly until 4th and 5th start to decently load the engine. It could be the transmission TPS is out of sync with the actual throttle position. It could also be that the pedal is not fully actuating the governor. You can recalibrate the 0 and 100% TPS input as well as force the trans to relearn the shift points, but it is a good idea to confirm the pedal works the governor input between the idle and high speed stop screws first. I did a video on how to check this and the TPS sensor over on Youtube.

Over on the hydraulic control panel the bottom right button is for the cab air suspension. If you push it in and turn it counter clockwise this should turn off the cab suspension and stop your air leak until you can get that fixed.

Fix your air leaks. The dryer can only adequately dry so many CFM, and when you start leaking air, the dryer will start to pass less dry air which can cause issues in the brake system. One of my other videos on utube shows how to clean out the air dryer to improve its efficiency.

 

[LMTV89]

Man you guys know your stuff! So the chassis from what I was told is a 89 1078 and the PO converted it to a 1079, so it has the 1079 box and tags on the inside. Whats the best way to confirm what it is? Do these have VINS or anything similar?

I will look into the air leak, its not bad, maybe 2 to 3x air that a bad coupler on the end of the airhose in the shop would leak. The weird thing is it doesnt do it all the time, does the cab mount purge air under any circumstance?

 

[GeneralDisorder]

Man you guys know your stuff! So the chassis from what I was told is a 89 1078 and the PO converted it to a 1079, so it has the 1079 box and tags on the inside. Whats the best way to confirm what it is? Do these have VINS or anything similar?

I will look into the air leak, its not bad, maybe 2 to 3x air that a bad coupler on the end of the airhose in the shop would leak. The weird thing is it doesnt do it all the time, does the cab mount purge air under any circumstance?

What does the data plate on your dash indicate? Do you have a serial number? Post pictures of the truck and any data plates you can find. We can tell a lot about it from how it's equipped.

FMTV's including the M1078 were still in the prototype stages in 1989. Stewart and Stevenson wasn't even awarded the construction contract till 1991 and about the oldest production FMTV's out there are generally 1992 models. So unless yours is one of the 15 prototypes I don't see how it could be a 1989 production truck.

Need more specifics on where this air leak is coming from. Above the leaf springs doesn't sound like cab air ride location - post pics.

 

[Third From Texas]

Congrats !

Yeah, the data plate located below the driver dash panel will tell you the year S&S made it (the font on the plate can even tell if it went back thru refit for BAE). Take a pic.

These trucks are super low gear and the shift points are crazy low. I do suggest reading the operator's manual before you just start pushing buttons (if you were to jam it into mode at highway speed, it could be bad). But it's all pretty simple (even retrieving error codes if the trans ever has an issue).

When I got my first truck the PO told me "avoid shifting from Drive>to>Reverse" (let it pause in N to unload, first). I took his word and a couple years later an Allison mech told me it was sound advice. Never seen that mentioned in the TM, though.

CTIS control (if it works) is pretty straight forward. Just select a setting and the pre-assigned psi is adjusted. Ideally after any/all air leaks are taken care of.

The system vents/dumps air back at the drivers-side vent between the batteries and rear springs. If it's constantly leaking, you may just have a stuck valve. You'll likely hear it occasionally chirp or hiss under the passenger kick panel if you play with the CTIS. Lots of experts here on the CTIS system.

Overfilling is pretty common given the massive volume of fluids in these things but easy to bleed off. Be certain to check the trans level, too (that's a very expensive Allison). And while you're checking fluids, be sure to check all four hubs (see the TM oor ask here for details on how to check it).

Yeah, you'll never refuel or park again w/o someone walking over. They either served and will tell you about the truck or they'll ask "what is that?" "And where did you get it?" *I usually tell them "the National Guard leaves the gate unlocked and I just try to get it back by the weekend".

Grab the TM's and start w/ the Operators Manual. It will go into a lot of good stuff and covers the basics very well.
*though the TM's can be a pita to navigate for specific info

And get a good air or battery-powered grease gun. Super critical to keep grease in those u-joints.

The trucks are notorious for 12v vampiric leaks. Causes starting issues (can even ruin a battery or batteries in a week). Get a charger on each bank asap! It's also advisable to drop from quad to dual battery. Easy to do and reversable. Something you may consider to save that $3000 alternator.

As far as the habitat goes, if the steel plates on the floor and wall haven't been removed yet and if you are just making a camper....ditch that extra 1000lbs.

Welcome to the club !

 

[LMTV89]

My bad guys, I found a tag under the steering wheel that says warranty start date 1999 so the chassis is either a 98 or 99. The only other tags I saw were on the side of the box and on the passenger door and they both say 1079 but the chassis is a 1078 with a winch. Other than the BOX is there any mechanical differences between the 1979 and 1078?

 

[Ronmar]

My bad guys, I found a tag under the steering wheel that says warranty start date 1999 so the chassis is either a 98 or 99. The only other tags I saw were on the side of the box and on the passenger door and they both say 1079 but the chassis is a 1078 with a winch. Other than the BOX is there any mechanical differences between the 1979 and 1078?

No, not really The upper frame rail has 4 box/pockets welded on it where the box subframe attaches with bolts and springs. The 1078 bed attaches to the frame a little differently. The truck chassis are the same, with one additional wiring harness used to connect the box to the power panel…

 

[GeneralDisorder]

Get rid of the Michelin MayPops as soon as possible. Those tires are all way beyond useful life - the military stopped using them more than 10 years ago so they are all much too old to use.

 

[NDT]

seriously you could not find this plate on your truck?

 

[coachgeo]

seriously you could not find this plate on your truck?

Pretty common for folk not to see that one. Many of newbies miss it. Maybe it's cause climbing in folk are too busy looking at foot / hand holds to not slip orrr?? Not sure..... but it certainly is common. When in driver seat your left knee obstructs it.

 

[Third From Texas]

Pretty common for folk not to see that one. Many of newbies miss it. Maybe it's cause climbing in folk are too busy looking at foot / hand holds to not slip orrr?? Not sure..... but it certainly is common. When in driver seat your left knee obstructs it.

Agreed.

I've seen plenty of new owners asking about info all the time who totally missed the placard.

I'm still finding things on my truck that I did know existed.

LOL

 

[chucky]

Congrats !

Yeah, the data plate located below the driver dash panel will tell you the year S&S made it (the font on the plate can even tell if it went back thru refit for BAE). Take a pic.

These trucks are super low gear and the shift points are crazy low. I do suggest reading the operator's manual before you just start pushing buttons (if you were to jam it into mode at highway speed, it could be bad). But it's all pretty simple (even retrieving error codes if the trans ever has an issue).

When I got my first truck the PO told me "avoid shifting from Drive>to>Reverse" (let it pause in N to unload, first). I took his word and a couple years later an Allison mech told me it was sound advice. Never seen that mentioned in the TM, though.

CTIS control (if it works) is pretty straight forward. Just select a setting and the pre-assigned psi is adjusted. Ideally after any/all air leaks are taken care of.

The system vents/dumps air back at the drivers-side vent between the batteries and rear springs. If it's constantly leaking, you may just have a stuck valve. You'll likely hear it occasionally chirp or hiss under the passenger kick panel if you play with the CTIS. Lots of experts here on the CTIS system.

Overfilling is pretty common given the massive volume of fluids in these things but easy to bleed off. Be certain to check the trans level, too (that's a very expensive Allison). And while you're checking fluids, be sure to check all four hubs (see the TM oor ask here for details on how to check it).

Yeah, you'll never refuel or park again w/o someone walking over. They either served and will tell you about the truck or they'll ask "what is that?" "And where did you get it?" *I usually tell them "the National Guard leaves the gate unlocked and I just try to get it back by the weekend".

Grab the TM's and start w/ the Operators Manual. It will go into a lot of good stuff and covers the basics very well.
*though the TM's can be a pita to navigate for specific info

And get a good air or battery-powered grease gun. Super critical to keep grease in those u-joints.

The trucks are notorious for 12v vampiric leaks. Causes starting issues (can even ruin a battery or batteries in a week). Get a charger on each bank asap! It's also advisable to drop from quad to dual battery. Easy to do and reversable. Something you may consider to save that $3000 alternator.

As far as the habitat goes, if the steel plates on the floor and wall haven't been removed yet and if you are just making a camper....ditch that extra 1000lbs.

Welcome to the club !

View attachment 901508

Looking good !

 

[chucky]

Remember ! All of us were B.F.N. to this stuff when we started and i still am cause i learn something about them just about every day ! Its what makes this so addictive ! And everything you do in public with these trucks are being watched closely by the karens and kevins that want them off the public roads anyways so assume someone is always watching !!!!!!! Welcome to the OUTFIT !

 

[LMTV89]

Maybe it's cause climbing in folk are too busy looking at foot / hand holds to not slip orrr?? Not sure..... but it certainly is common. When in driver seat your left knee obstructs it.

This LOL

Still working on the graceful entry / exit.

FYI mine is under the steering wheel on the right side in-between the column and heater so it is out of view. In that pic it looks like its on the outside of column.

 

[coachgeo]

This LOL

Still working on the graceful entry / exit.

FYI mine is under the steering wheel on the right side in-between the column and heater so it is out of view. In that pic it looks like its on the outside of column.

what does the serial number start with A or A1? and yes..... by right knee would be unusual for A's (we call them A0's) Thought the A1's are by left knee too. Oh and also there likely is Date of manufacture and a date of Service.... what are those?

 

[ExtremeTruckMT]

Agree with GeneralDosorder, ditch the Michelins. The sidewalls crack and leak. Good videos out there on changing the tires. Welcome, and good luck.