LMTV Alternator Disaster, engine now catastophic

They're normal. You can find them, or equivalents, anywhere that carries heavy duty truck parts. There are a few other part numbers to try in my spreadsheet.

Awesomeness said:

They're normal. You can find them, or equivalents, anywhere that carries heavy duty truck parts. There are a few other part numbers to try in my spreadsheet.

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Thanks. I really just need an end cap.

I don't think you can get just an end cap, or at least I've never seen one separately. The u-joints are under $50/ea.

Awesomeness said:

I don't think you can get just an end cap, or at least I've never seen one separately. The u-joints are under $50/ea.

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Yeah I already figured so. I am just trying to get through one problem at a time haha.

Big day yesterday!

So ran into overtime on Friday but they got me out the door. We did go with a 8" SAE bolt that was kind of close and they managed to get the bolts out, although I think one of them is M10 now They loc-tited everything and I got on the road about 7. I thought for sure it was going to break down but with each passing hour my confidence grew until I was sure this was going to be fine.

I made into Richland but just past when I pulled over to check things out and the engine was making a lot of steam. I smelled coolant and noticed some dripping and thought - you know - this is a problem for the morning. So I grab a sleeping back and rack out. The next morning I tip the cab and water is dripping pretty quick from somewhere in the front of the engine. Great. I'm nowhere but Prosser is 10 miles on so I refill the coolant and get out there. Get into a NAPA, buy an armful more coolant, and then go over to the love's.

The service center guy and I take a look at it and it looks pretty squarely like the waterpump. Only problem is they have a policy against engine work and there was nobody in town who does cat stuff anyways. So I either had to continue on to Yakima (about 45 miles) or back about the same to Richland. The shops in Yak were all closed through Tuesday it seemed, but I figured if I had to tow, it wouldn't make a difference if I towed from the love's or from the side of the road.

So I figured lets go, and poured coolant through it all the way to Yakima. I was going through about 4-5 gallons every 20 miles, but it ran fine. I'd just go until the heater cut out, pull over and fill it again. So I get into Yak and it went well, relatively. I thought about leaving it there, but ... there's the walmart. So I bought 30 jugs of water and got back on the road. I figured if I could make the pass into Ellensburg it would forecast the pass. Got in fine to Eburg and just went for it. It held pretty steady at 5g per 20 and I got it over the pass.

North Bend (home turf!) TA is open, and the guys are chomping at the bit to fix the truck, but no pump in stock. They spent about 20 minutes trying to x-ref it from the handful of parts numbers I gave them but no dice. I was ultimately trying to get through to Bellingham and things had gone well since Yakima so I figured what's another 100 miles (other than 25 gallons of water). Things were going swimmingly until about I-405 and 165th when I heard a bang. Gauges are good but heat cut out ahead of schedule (I had been watching the ODO like a hawk to time the water stops).

Pull over and it's just streaming out. I fill it and make it maybe 4-5 miles and have to fill it again. Luckily at this point I was near my friends shop so I got it over there, and we parked it in his yard. Tip the cab and look around and my brand new fan, installed the day before by the mechanics, had thrown a blade into the radiator. Sigh.

The fan I bought NOS from a vendor known to the site, but I am not going to say who because I don't think they are in any way responsible. It came well shipped, factory packaging, etc. I want to raise the issue though that maybe these things have a shelf life, I don't know. My previous fan had also thrown a blade (was that way when I got the truck). So I don't know what the deal is here.

But the truck is safe, and I can work on it there. I'm going to the Seahawks game today and I am going to try to not think about it at all, and then I'll get to ordering parts on Monday I guess. The radiator I think we'll try to repair but we haven't seen the hole yet - they are all brass right? Looked that way at a glance anyways.

aleigh said:

Big day yesterday!
So ran into overtime on Friday but they got me out the door. We did go with a 8" SAE bolt that was kind of close and they managed to get the bolts out, although I think one of them is M10 now They loc-tited everything and I got on the road about 7. I thought for sure it was going to break down but with each passing hour my confidence grew until I was sure this was going to be fine.

I made into Richland but just past when I pulled over to check things out and the engine was making a lot of steam. I smelled coolant and noticed some dripping and thought - you know - this is a problem for the morning. So I grab a sleeping back and rack out. The next morning I tip the cab and water is dripping pretty quick from somewhere in the front of the engine. Great. I'm nowhere but Prosser is 10 miles on so I refill the coolant and get out there. Get into a NAPA, buy an armful more coolant, and then go over to the love's.

The service center guy and I take a look at it and it looks pretty squarely like the waterpump. Only problem is they have a policy against engine work and there was nobody in town who does cat stuff anyways. So I either had to continue on to Yakima (about 45 miles) or back about the same to Richland. The shops in Yak were all closed through Tuesday it seemed, but I figured if I had to tow, it wouldn't make a difference if I towed from the love's or from the side of the road.

So I figured lets go, and poured coolant through it all the way to Yakima. I was going through about 4-5 gallons every 20 miles, but it ran fine. I'd just go until the heater cut out, pull over and fill it again. So I get into Yak and it went well, relatively. I thought about leaving it there, but ... there's the walmart. So I bought 30 jugs of water and got back on the road. I figured if I could make the pass into Ellensburg it would forecast the pass. Got in fine to Eburg and just went for it. It held pretty steady at 5g per 20 and I got it over the pass.

North Bend (home turf!) TA is open, and the guys are chomping at the bit to fix the truck, but no pump in stock. They spent about 20 minutes trying to x-ref it from the handful of parts numbers I gave them but no dice. I was ultimately trying to get through to Bellingham and things had gone well since Yakima so I figured what's another 100 miles (other than 25 gallons of water). Things were going swimmingly until about I-405 and 165th when I heard a bang. Gauges are good but heat cut out ahead of schedule (I had been watching the ODO like a hawk to time the water stops).

Pull over and it's just streaming out. I fill it and make it maybe 4-5 miles and have to fill it again. Luckily at this point I was near my friends shop so I got it over there, and we parked it in his yard. Tip the cab and look around and my brand new fan, installed the day before by the mechanics, had thrown a blade into the radiator. Sigh.

The fan I bought NOS from a vendor known to the site, but I am not going to say who because I don't think they are in any way responsible. It came well shipped, factory packaging, etc. I want to raise the issue though that maybe these things have a shelf life, I don't know. My previous fan had also thrown a blade (was that way when I got the truck). So I don't know what the deal is here.

But the truck is safe, and I can work on it there. I'm going to the Seahawks game today and I am going to try to not think about it at all, and then I'll get to ordering parts on Monday I guess. The radiator I think we'll try to repair but we haven't seen the hole yet - they are all brass right? Looked that way at a glance anyways.

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Man! If it weren't for bad luck you wouldn't have any luck at all, it seems from where I'm sitting, about to pull my HMMWV outta the garage for a spin with my dog as I've been promising for a week (headcold, work, haven't done much of anything else).

Following this tale of woe and many travails with bated breath. No way I'll ever buy one of these beasts now - unless I win the powerball lottery.

And you wanted to take this truck deep into Mexico??? I love my LMTV but the days of these being "ultra reliable" are long over.

NDT said:

And you wanted to take this truck deep into Mexico??? I love my LMTV but the days of these being "ultra reliable" are long over.

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Just carry spares. Like an entire spare drivetrain/ECMs/radiator/tires. Isn't that what flatbeds are for?

NDT said:

And you wanted to take this truck deep into Mexico??? I love my LMTV but the days of these being "ultra reliable" are long over.

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No, I didn't, not in the state it was in (even before these problems). I feel like that thread got out of control. I also wouldn't have taken a trip without a sure way to recover it, either a commercial service or more likely going with a pack of vehicles, which is what I was always contemplating, even though nobody asked.

I'll say this in general, you know, these trucks are old. We all know that. We need realistic expectations. This does include the LMTV and if people are saying they are reliable just because of the design or because they are from the 90s, that's nuts. Here's my attitude about the problems I am having right now.

I think that poor maintenance on my part let the alt bolt get loose. As LMTV owners we all know that thing is a problem and in the 16k of relatively trouble free miles I've gotten out of the truck since I got it - including several trips over 1000 miles - it loosed up at least once. I didn't check it, and I should have. So somewhere it probably rattled off and no surprise the alt broke off.

The water pump I think went because the system boiled. It was weeping steam from here and there, all over. Prior to that the thing had been perfect, holding 185 degrees all the time, even in 120+ degree weather in Arizona. The fan I don't really know. That's interesting.

I drive the truck, I enjoy the truck, and I am fortunate enough to have the resources to deal with it when it breaks. I could have just flown but what fun would that have been!

I suspect you will find the water pump shaft with substantial slop on the impeller shaft when it is pulled. That imbalance probably cooked your fan clutch or was enough to cause the fan to fail or the shaft of the pump cracked and launched a missile. I am afraid all the problems will track back to the water pump.

Start with fresh belts, water pump, new hoses etc.....

This ^^^

Glad you were able to make it back to Washington and your Seahawks game.


Sent from my iPhone using Tapatalk
Man of few words

M1081 LVAD

"How do the alternator, waterpump, and fan all break when they aren't connected together?". Unless it's all random chance, you have to shake all of them together. There are now several posts where the pattern of broken parts is almost the same... water pump, alternator, starter, fan, u-joints... all stuff bolted to the extremities of the engine, getting broken off. A resonant vibration is the most likely culprit. And if the vibration was there breaking and loosening stuff, continuing to drive after things are loose and weakened is certainly going to destroy it for good (I get it, sometimes you "have to", but at that point, you're just accepting the consequences you expect to come).

When you look at the list of broken stuff, the trick is to figure out the root cause. The broken alternator couldn't have done much to break the fan, and the waterpump couldn't have broken the alternator. None of the broken stuff on the engine could have damaged the u-joints/driveshafts, but the u-joints/driveshafts could have set up a resonant vibration that got the engine "bouncing" (like the Tacoma Narrows Bridge or how an out of balance tire gets bad at certain speeds) and shook all that stuff off the engine.

This theory again aligns with information we have that the driveshaft system had destructive tendencies in the past. Because the underlying issues are still there, if they are aggravated by something (e.g. a loose u-joint or cap), it brings down the house of cards.

What an ordeal. I have a list of things to double check on my truck. Glad you made it on time for the game. I checked my stockpile of stuff for an alt bolt, no joy on that. I agree on what you say, as these are old trucks for reliability. I know brad down in makenna has some parts trucks now, may be a option for parts.

Glad you got the resources and wit to deal with the ins and outs!!

Just some old stories
View attachment LMTV ADA366822 - LMTV Driveline Failures.pdf

View attachment LMTV ADA416765.pdf

View attachment LMTV problems and industry 11132017.docx

View attachment LMTV story.pdf

Well Guess at some point when $$$ exist.... I might add the suggested type CV jointed front driveshaft to my build since I do hope for long trips with little possible hickups. Already going to 6x6 rear for same reason.

OP may have seen this thread already, but from my reading it seems these issues come from worn/out-of-balance drivelines, as unrelated as it seems...

https://www.steelsoldiers.com/showt...g-water-pumps-and-loosing-alternator-brackets!


Page 9:

Duckworthe--
"So I took my truck into my buddies driveline shop here in San Diego he also works on many military trucks contracted through the Gov.. He looked at my shafts and said "Eric, your u joints appear to be fine, however the slip joints are shot." I told him that the manual has allowance for .005 hinging. He laughed at that and said "sure if you want to risk blowing your driveline. That is an allowance put in place to basically allow these trucks to keep moving or (be allowable to drive". My truck now has 20,000 miles on it. And his words were more like 120,000 by the spline wear. He said either buy new or rebuild them. I chose to rebuild them as I don't know what I am really going to get buying someone's parts. If I had to pay for the labor and parts it would be $500.00 per shaft. I only have to pay for parts so its about 175.00 per shaft. Unless a u-joint needs replaced also. He said that there should be NO, as in zero, hinging movement in the shaft. As for the drive line angles, he said that will wear out u joints faster but not the splines. His quote to share was "If you want to risk blowing a driveshaft and transfer case, and further possible damage, go with the .005 hinge plan. But that is just for moving the truck around some. Not travelling down the highway going to the desert for the weekend." So I am pulling my shafts today and having him rebuild, dynamically balance them, and give them back to me 100% ready to go. I can't risk the possible damage to major components. I provided him with the study report posted prior I the chain. He will read it and give me his understanding of it. Todd has been building Drivelines for cars through semi trucks for over 45 years. He has built all of my off-road race truck and circle track shafts for about 20 years, so I trust his assessment and knowledge. I will get them back after thanksgiving and will reinstall them followed by a report of any truck characteristic changes. I hope this helps some of you out there. My bottom line is this. $1000.00 vs. a transfer case or more is money well spent!"


Duckworthe--
"I dropped my shafts off yesterday to get rebuilt. Shaft came out easy, but boy are they heavy, especially the rear. I will have better then new shafts and joints when returned. I did ask him about the commercial trucks tolerances. In civilian world they don't call it a hinge test or hinge movement, its called Lateral spline movement. His answer was, quote "zero, if it has lateral spline movement it needs to be replaced." end quote. Again my truck has 20,000 miles on it now and he said it looks like 120,000! the only real thing wrong with my u-joints was the cap seals were dried out. So I am just starting totally new on these items. Probably wont get them back till after Thanksgiving as he is booked up with paying customers. But I will post what I find after rebuild and reinstall.
I forgot to mention that he stated that, quote "with ANY lateral movement the test stand will reject the shaft and stop the test. The reason that lateral spline movement is so bad is every time the shaft turns it drops however many .0001 it is off. this Dropping effect is basically where most of the vibration will come from and it turns into a pounding/shaft dropping force that will beat the shaft apart and or push driveline vibration to other areas of the truck. Since our trucks have automatics the end results are far worst and devastating. On a manual trans you might not notice it as much because of the huge and heavy gears that can take more forces placed on them then an auto can take through its small trust washers." end quote. He also stated that he sees trucks with far worst driveline angles everyday. Our trucks angles are nothing and my joints are in amazing shape minus the dry cap seals.
Thanks,
Eric"


Page 11:

Duckworthe--
"So I received my drive shafts back from the shop yesterday and installed them. They always look brand new when Todd rebuilds shafts. They went right in. I use a $10.00 bottle jack to remove or install my shafts. Just as easy and way cheaper then the $250.00 tool and I carry the bottle jack to change a tire anyway. I also carry 2 longer bolts to put through the caps to make sure the bolt holes line up correctly when installing them. If the are off, you will have to remove them again. So it is just an easy way of making sure they go in straight/correctly. So, now that they are new shafts there obviously ZERO lateral/ hinging movement in the splines. I took it for a test drive and it is so much nicer. There was vibrations before that are not there now. My truck had noises and vibrations from the day I got her and I knew no difference. But now I can tell that the shafts were a source because it isn't there anymore. I also built a new upper alternator mount to replace the second one that broke. We will see how this one hold up. I know it will as now the vibration is gone and I also made it a little better and better quality then original. I will be heading out on the 21st through the 2nd on a trip through Arizona. I will give everyone an update upon return. I will also start a new thread about fixing my Alternator that broke the 24 volt stud off. What a pain! Merry Christmas everyone."


Duckworthe--
"So last night I took the truck for a drive again. I can't explain the difference of how the truck drives with these new shafts in place! Noises that I thought might be normal are no longer there. I highly recommend getting your drive shafts rebuilt. My shafts were within the tolerances for lateral/hinging measurements but WOW what a difference it makes having no vibrations! price of rebuilt shafts vs. damage to the truck= best money I have spent!"

A few points:

1. If someone put together an "emergency" kit that included: Alt L bracket, Alt Bolts, Alt belt, Water Pump, Water pump belt, Water pump seals, Easy out, drill bit, Loctite. I would certainly buy one. Anything else that would be required to make sure you can sort out this alternator problem the first time you notice it's loose. Sounds like potentially a U as well.

2. I've read a few trucks have the fan blades go through the radiator. Would be be possible to fab a metal(steel) shield to protect the radiator from the fan?

3. Towing services. Could we put together a guide on how to get the LMTV towed and expected prices (general ideas). I personally have no idea who to contact if I break down somewhere.

4. Find a scientific way to measure the driveline vibration to meter and predict when it's doing damage?

5. Write a PMCS guide for which bolts and things to check regarding this vibration issue? I think it's in a few threads but summarizing it would be great. I've already lost the top alternator bolt twice. Fortunately they are cheap and common.

Bet that was a nail biting game to watch in the stands!!