Multifuel Engine life - the facts from Uncle Sam

[DDoyle]

I am as big of a fan of this engine as anybody - this is a quote from an offical Army monograph of logistics in Vietnam (Library of Congress Catalog Card Number: 72-600389), so don't argue with ME about what it says.

The author of this monograph, Lieutenant General Joseph M. Heiser, Jr., had been engaged in planning and directing logistical support to the U.S. Army soldier, other U.S. Services, and the Armed Forces of Allied Nations since his commissioning as an officer in the Ordnance Corps in 1943. Having served in the Southern Base Sector Command of the European Theater of Operations from 1943 to 1945, he became a staff officer of the Office of the Chief of Ordnance. He later served as the Executive Officer of the Ordnance School and Division Ordnance Officer, 7th Infantry Division, Korea. He was designated Commanding General, U.S. Communications Zone Europe in 1965. He then became, successively, Assistant Deputy Chief of Staff Logistics (Supply and Maintenance), Headquarters, Department of the Army, Commanding General of the 1st Logistical Command, Vietnam, and Deputy Chief of Staff for Logistics of the U.S. Army



A minor typo in the original document - "LD 427" should be LDS-427.

Best wishes,
David Doyle

"Service Support in Vietnam:
Transportation and Maintenance

Though not a maintenance fault, failures of multifuel engines created the requirement for a major off-shore maintenance effort and a sizeable supply problem. In January 1967, more than 300 5-ton trucks were deadlined in Vietnam because of inoperative multifuel engines (a similar condition existed for 2½-ton trucks) due to cracked blocks, blown head gaskets, valve stems and connecting rods. A study indicated that many failures occurred between 9,000 and 10,000 miles and that the units hardest hit were the line haul transportation units whose engines were subjected to continuous use (2,000 miles per month in Vietnam). The prospect for improvement at this point was negligible because of the lack of repair parts and overhaul capacity. Multifuel engines powered both 2½- and 5-ton trucks. A similar condition also existed in Thailand. The annual engine replacement rate of 6 per 100 vehicles per year increased to a rate of one engine per vehicle per year.
By the summer of 1967, an airlift program, Red Ball Express was put into effect in an attempt to alleviate the shortage of engines and repair parts. The Red Ball Express was designed to be used in lieu of normal procedures exclusively to expedite repair parts to remove equipment from deadline status. Reserved and predictable airlift was made available for this purpose. The seriousness of the situation led to a multifuel engine conference on 28 August 1967. The conference resulted in several recommendations, the most significant of which was that three multifuel engines, LD 427, LD 465, and LDS 465, were to be placed under Closed Loop Support management because of the inability of units in the field to cope with the maintenance problem. A further recommendation was made that return to the Continental U.S. be authorized for vehicles that could not be supported with multifuel repair parts or replacement engine assemblies. Because a large percentage of the producers' production capacity was consumed in end items assembly, some repair parts and new replacement engine assemblies were not readily available. Department of the Army approved the recommendations of the conference and directed that necessary retrograde, overhaul, and shipping operations be initiated immediately.
Although the conference had focused attention on the supply aspect and premature failure of engines, significant intangibles remained unsolved, including proper operation of vehicles and user maintenance. Because of the characteristic difference of the multifuel engine from the standard internal combustion engine, periodic maintenance and specific mandatory operational procedures differed sharply from procedures used with other vehicles and required closer attention. Simply put, despite years of testing effort, the multifuel engine did not possess the ruggedness and tolerance to withstand the abuses inherent in field operations."

 

[Chevytruck]

wow didnt know that

thanks for telling us!

 

[beaubeau]

Wow! With all that, I don;t remember us" Marines", losing any Motors while I was with the Engineers. Of course we Lost the Trucks because of Mines and Accidents. This was in Feb. 68 through Oct. 69. We did have a good Preventive Maintenance Program and Monthly Services. I still say these vehicles were Beat On Muchly, by Servicemen who didn't give a Hoot about Uncle Sams Equipment. I cannot remember, but we may have had Mack Motors in our trucks.

 

[dk8019]

I've talked to a few guys with prior service driving the Deuce and others and most admitted that when they drove the units in the field or in convoys where they could run at open speeds they did so with more or less reckless abandon, that is beyond the danger line, as fast as they could just to make the trip shorter. It's no wonder rods went through blocks etc when used like that.

 

[Bill W]

Being the 427 seemed to have the same faliure rate as the 465 leads me to think it was more then just a engine design problem ( ie bad driving and maintinence ). I also remember reading a article here that somewhere around 1969-70 the manafacturers ( after getting data such as the above) changed a few things on the 465 to make them more reliable ( ie headgaskets ,different injectors, etc ) of course I can't remember who posted that article

 

[ETHOS]

wow, we need more info, this is interesting

 

[hole]

Thank you David! I'm hopeful this info comes from your most recent research , ultamitly leading to a new book (Please )

 

[desertfox]

I was in Nam and in the Corp same time as beaubeau and yes in my unit we did drive the deuces with "reckless abandon". We did nothing slow. Faster the better. And I do not recall distroying and engines either. We did not loose trucks in that manner. We had multifuels and all were whistlers.
Since we have alot of members that have modified their engines with improved filtering systems as well as pre-lubers I would like to see some data from those members. Hope they have been keeping records?

 

[randyscycle]

My Father who was a Seargent inthe US Army in Lai Khe Vietnam in the 1st Infantry Division in 1969-70 and worked in the motor pool had this to say:

"We constantly had at least one or two trucks deadlined at any given time as far as deuce and a halfs were concerned. These were all the older ones that did not have the top stack, but the exhaust coming out the bottom. We (his unit)didn't have any of the top stack trucks in country, and I only saw a few of those stateside before being discharged. It was my understanding that the non-running trucks were supposed to be shipped to the Phillipines for major overhauls. At least that was what I was told, anyway."

That is exactly as he told me.

 

[steelandcanvas]

Not to doubt David Doyles research whatsoever, however in the 6 years I spent around Motorpools, I don't recall a Deuce being "Deadlined" for leaky head gaskets or a rod exiting a cylinder wall. I would imagine in wartime the Guys run the vehicles alot harder and maintenance is "when there's time". Just my

 

[saddamsnightmare]

November 29th, 2008.


Gentlemen:
Between you, I and the wall, I think David gets his insights just about the same place Moses did! I am awaiting his magnum opus on the G-742's, and hope it's "Biblical" in status as well as thickness..... The Multifuel engine is and was a product of its time, and I am sure with enough abuse many engines gave out.... Some of the design issues are still with us (slow oil pressure build up, low redline speeds-gotta watch the downgrades on the highways,boys!), but the engine design, while primitive, seems pretty much up to pulling the deuce, whether it can stand a 5 or 10 ton for long would, in my mind, be doubtfull.
And as most of us won't be outrunning Charlie or Hamad to save our bacon and our load, they should do pretty well in our overgrown pick-up duty world.
PREVENTITIVE MAINTENANCE is the two words for the day....


Cheers,

Kyle F. McGrogan

 

[ETHOS]

so who here has the deuce with the most miles on a multifuel engine?

 

[jim-m35a2]

I have a 1971 General Products Deuce with a 1980 White engine with 14500 miles , according to the speedo.

Jim
________
Ipad Accessories

 

[OPCOM]

35,000 miles here on a 1991 Tooele rebuild of the '68 M35A2.

Anything before 17,000 miles Jeff Symanski would have to comment on because he owned it then. Not sure if he is on here.

The latest 18,000 miles:
Mixed traffic (in town)driving of 8000 miles.
Highway speeds of 50-55 for 10,000 miles.

The last 18,000 miles have been with a fixed load of 3 tons. There is no evidence of impending major malfunctions, but I understand they often come as surprises.

 

[vtdeucedriver]

I can add to this so maybe you guys can understand where that report came from. I have a copy of that report and many other reports from Line Haul units in Vietnam. These reports were info that was put together because of the issues with the Multi-fuel engine in Vietnam. I have interviewed drivers, unit commanders, convoy commanders, supply officers and motor pool mechanics. All will tell you that the Mack ENDT-673 was the engine of choice for the Line Haul units. Drivers of the 673 would often give a friendly push up the passes ( this was a big no no and a ticket could be issued) because of the difference in power bands between the two truck. So the mack driver will usually not back off and just give a nice bump ride up the pass.
In this time of the reports of failures, only 30% of the roads used were paved. Even tho landmines and enemy rockets took their tolls on vehicles. Pot hole covered roads and dust and mud also did their part. This would cause drive line and brake failures constantly during a convoy run. So often that if a Unit had them, a spare or 2 bobtails would run without trailers for brakedowns. Now what do you do when traveling down a mountain pass with a vehicle at 45,000 lbs with no brakes?????? Some of you here had read DD's thread on brakes....... The E brake would not do anything so many drivers would try and control the speed by compression. This would put such a strain on the engine that after the recovery ( if the engine was left at all) its survival after the repairs would be very short.
Another comment was made here on the SS that "kids will be kids". I will assure you that those guys did the best to take care of their stuff. Unlike WW2 and the redball express, in Vietnam there was a very good chance that in the bushes the enemy was lurking and wanted to kill you so the last thing you wanted to do was beat on the equipment that you needed to get you to the safety of a perimiter wire!!!
Now I do know for a fact that trucks were tweaked with. They certinly did turn the fuel up for a faster speed and more power. But at this time of the war, the only trucks that this was done to was the Gun Trucks (at least by 5th Maint Bn)

Now I also have chatted with many members of the 5th maint Bn. They were the heavy maint outfit that did much of the big work for 8th GP units. They all concur that the Multi was a weak engine (again comparing to the ENDT-673). At the time of the reports, they were canibalizing what ever they could to keep the Multi-fuels on the road. Only until the direct supply line of the Red-ball did parts come in and vehicles were able to be returned to the roads.

Well now that I said all of that, some of you wont need to read a article that I have been working on for the Military Vehicles Magazine

 

[ARMYMAN30YearsPlus]

The Multifuel is not an inherently weak engine it is subject to some specific design issues that have been mentioned but I am an Army Transporter with many years of truck operations and can tell you that the dueces usually got over rev'ed by Soldiers if they took them on the road. It is one of the reasons the Army spent nearly a thousand bucks a pop to put Argo Tachographs in our trucks. A good tach program when supplied with new weekly discs and a Truckmaster who knew how to read them and administer the program saved countless engines from over rev'ing. Almost every duece problem we had was a sprag related one not an engine one. We even kept one in the heated motor pool so on below zero mornings we could start it up and go out and jump the 60 tractors that sat out all night. I am glad to have two multifuel trucks now and will not abuse them and in time will put pre lube systems on them. I expect them to last at least as long as my 6.5 TD in the Suburban which is at 130K now and running strong.

Thanks for the post David I think the Army understood that most problems were operator induced but due to war took on the cost as a point of keeping the war going. I would like to know how many hours the MTBF is for an old Huey UH-1 compared to the multifuels we own today.

 

[Big Mike's Motor Pool]

my one deuce has been a beater ever since it left the hands of drmo way back when. it was purchased by joe young around 98' i beleive. it then was bought by a guy i know named pat. he bought it for a toy to play with on holiday weekends in the summer at a major word of mouth type underground mudding event here in the jersey pines that doesnt happen anymore. i have seen pics of my truck in his hands with waves coming over the windsheild. when i got it the heater didnt work. the prolem was clay in the heater core. this tells you of the abuse it got. i bougt it from pat in 2001. its life actually got harder when got it. swamping it, running trees over, 3,000 rpm on the tach, usually 2-3 quarts low on oil and never enough coolant in the leaking radiator should have killed my truck. it sits in my yard now because the wheel cylinders didnt agree with me doing a dot 3 swap. my engine runs beautiful. 35,xxx miles on it. although not indestructible, multi fuels will take their share of abuse in my opinion. i must also add that i never lost oil pressure or over heated my engine. thnis might have somthign to do with it. i did learn that i dont like working on deuces cause im lazy. my new truck wont get the same abuse number one did........unless i buy another clean one from GL

 

[cranetruck]

The army elected to stay with the multifuel for the, then new m656/xm757 series of 8x8 5-ton trucks, so the advantages must have outweighed the (operator) problems. Continental did add some design changes, though, a 5th piston ring and tighter tolerances to give it a higher governed rpm (3,000)....

 

[Dodgeman1941]

My 1970 AMC-Jeep, '86 rebuilt M35a2 has 63,000 on the speedo and I've put 7,000-8,000 on it in the 6-7 years I've owned it

 

[Recovry4x4]

I'm in deep doodoo. I run mine for hours at a time at 55+ miles per hour. I've done that with every multifuel deuce I've owned. I am cognizant of where the RPMs are and when rolling the down side of a hill I wait for the last second mash the pedal. Luck or good sense has been with me right along as I've never hurt one but just in case, I'm stocking up on motors.