LMTV FMTV Driveline Failure Investigation

[VehiCROS]

Upon seeking information and researching purchase of a M1078 LMTV I found a book costing $105 from Amazon, but thanks for my wonderful counterpart who just so happens to be better with internet searches than myself, I was able to find the publications at no cost. I am a new member to this forum and would like to contribute my discoveries, which will hopefully benefit all those who bravely sought out a retired military vehicle (LMTV/FMTV) as part of their way of life.
Please see the multi part series of the MTV drive line failure investigation and conclusions. Simply put, the drive axles of all LMTV/FMTV vehicles exceed a safe operating angle, and should NOT exceed speeds over 58 mph, or perhaps the "High speed/Highway Gears" are a makeshift solution to reduce chance of failure by reducing driveshaft rotational speed.

PDF Download Links:

Testing and Evaluation of the LMTV Driveline and Flywheel Failure INTRODUCTION

Testing and Evaluation of the LMTV Drivetrain Failure Part 1 of 3

Testing and Evaluation of the LMTV Drivetrain Failure Part 2 of 3

Testing and Evaluation of the LMTV Drivetrain Failure Part 3 of 3


This is very useful information, although NOT worth the $105 x3 that Amazon charges.

LMTV Flywheel Housing and Driveline Failure Investigation. Part 1 of 3: Hayes Hobolth: Amazon.com: Books

LMTV Flywheel Housing and Driveline Failure Investigation. Part 1 of 3 [Hayes Hobolth] on Amazon.com. *FREE* shipping on qualifying offers. LMTV Flywheel Housing and Driveline Failure Investigation. Part 1 of 3

www.amazon.com

 

[gringeltaube]

Simply put, the drive axles of all LMTV/FMTV vehicles exceed a safe operating angle...

You prob meant to say driveshafts (or better propeller shafts)...?

 

[VehiCROS]

You prob meant to say driveshafts (or better propeller shafts)...?

Yes, it was late last night and I hurried to upload the files. This is all somewhat due to I am about to purchase a LMTV or FMTV and during my search I noticed many of the surplus trucks on govplanet have either broken or missing driveshafts. I found this to be highly unusual and stated searching for answers.
Id like some input as to the truth about replacing the planetary gears with "high speed" gears and if doing so could reduce the change of failure provided the operator reduce engine RPM without exceeding speeds detrimental to the drivetrain.
I would also like input concerning the effects on a 4x4 (LMTV) with Cat 3116 VS FMTV with increased HP.
The documents pretty much tell everything, but the extensive reading may be a little more than my comprehension allows.
Plus I personally feel that since the main driveshaft of the 6x6 is no stronger than the ones used on the 4x4. it is more likely to sustain damage. True or False?

 

[VehiCROS]

You prob meant to say driveshafts (or better propeller shafts)...?

Oh, BTW, I had tested the links on the post but did not see any way I could possibly edit my original post to correct the URLs, However I did try to correct them , and use titles instead of displaying the actual URLs, which I kinda prefer.
THanks

 

[gringeltaube]

I just moved this thread to the FMTV sub-forum, where you can edit your posts all you want.


Please don't forget to add your state in your Profile/Location.

 

[JD4044M]

Wow what a report to read!! I too have just bought one and soon will be here to inspect. Mine only has 2180 miles on it but the report bothers me. I will inspect the Shafts and slip splines for play. I have the tools to measure this with. Probley should find a supplier on some new Universal Joints to keep on hand just for the future. What I get out of the report is the angle is steep, road speed should be at 50 MPH or less and stay out of the water for grease problems. I can do all of this where I live with out a problem. Just wondering why they sold mine at 2180 miles if cracks were forming in some of the parts in the drive train. Hoping it I just because they are phasing them out. I will not be working mine as hard as they were designed for. My heavy loads will be hay once a year other then that it is more of a toy or empty cruiser just to enjoy driving to town a lot on our country road about 12 miles long in the Boonies. A few of the miles are a gravel/dirt road. After reading this not sure I would spend the money to turn one into a fancy RV to tour the USA/World in??? I should get my manuals today and will look over maintance on the shafts U-Joints. I know a guy who builds Drive Shafts for heavy equipment and balances them on a lathe. Wondering why they did not go to a constant velocity joint instead of a single universal for the angle. I know they make shafts for steeper angle then this has and way more HP on them.

 

[coachgeo]

Upon seeking information and researching purchase of a M1078 LMTV I found ....

PDF Download Links:......

Thank you for wanting to be a positive participant. all those pdf's are in here.... though not sure they are all in one thread. Has been discussed pretty extensively in here as well as you might guess. A search should find numerous discussion on this. After you pour thru them you are bound to have questions/insights that were not covered.

The existing threads with the info that lead to your question or new insight... is best place to post new things. This way others can read back and then follow on with your new questions and/or insights.

 

[VehiCROS]

Thank you for wanting to be a positive participant. all those pdf's are in here.... though not sure they are all in one thread. Has been discussed pretty extensively in here as well as you might guess. A search should find numerous discussion on this. After you pour thru them you are bound to have questions/insights that were not covered.

The existing threads with the info that lead to your question or new insight... is best place to post new things. This way others can read back and then follow on with your new questions and/or insights.

Well OK if that is the case then you should ask the moderator to completely delete my posts, Thanks.

 

[JD4044M]

Some times we miss stuff I am new here and have not even came up with what to search for yet. Glad he posted that cause reading another post here they talked about it some but not the detail these reports did. Don't delete them there all together and nice to have seen them to read. The time I would have searched about them would have been when my driveshaft dropped out. Now I know what to look for before it happens.

 

[Reworked LMTV]

Upon seeking information and researching purchase of a M1078 LMTV I found a book costing $105 from Amazon, but thanks for my wonderful counterpart who just so happens to be better with internet searches than myself, I was able to find the publications at no cost. I am a new member to this forum and would like to contribute my discoveries, which will hopefully benefit all those who bravely sought out a retired military vehicle (LMTV/FMTV) as part of their way of life.
Please see the multi part series of the MTV drive line failure investigation and conclusions. Simply put, the drive axles of all LMTV/FMTV vehicles exceed a safe operating angle, and should NOT exceed speeds over 58 mph, or perhaps the "High speed/Highway Gears" are a makeshift solution to reduce chance of failure by reducing driveshaft rotational speed.

PDF Download Links:

Testing and Evaluation of the LMTV Driveline and Flywheel Failure INTRODUCTION

Testing and Evaluation of the LMTV Drivetrain Failure Part 1 of 3

Testing and Evaluation of the LMTV Drivetrain Failure Part 2 of 3

Testing and Evaluation of the LMTV Drivetrain Failure Part 3 of 3


This is very useful information, although NOT worth the $105 x3 that Amazon charges.

LMTV Flywheel Housing and Driveline Failure Investigation. Part 1 of 3: Hayes Hobolth: Amazon.com: Books

LMTV Flywheel Housing and Driveline Failure Investigation. Part 1 of 3 [Hayes Hobolth] on Amazon.com. *FREE* shipping on qualifying offers. LMTV Flywheel Housing and Driveline Failure Investigation. Part 1 of 3

www.amazon.com

Thank you for sharing this and welcome to the forum : ) Although some of us have seen this, we all appreciate a spirit of paying it forward! Sharing information is the key to keeping these trucks on the road.

 

[coachgeo]

Well OK if that is the case then you should ask the moderator to completely delete my posts, Thanks.

nah...deleteing would be a disservice.... aka..... agree with everything Reworked said... besides bringing it up again helps other newer folk too . LIke yourself and JD4044m its is all new to them so your post raised awareness. besides....... like mentioned... having the links all in one place is good thing and don't think that was the case in past threads....

look forward to questions/insights that come to your mind. Bound to be some. Read thru the old threads and post up. do agree the search in here sucks. advanced google search helps. will try to find a few of past discussions on them for you. Had links to these discussions and others all organized in notes in my old account here for easy access but when they updated this site a few months back it ate all of it . Slowly doing it all over again and organizing via bookmarks this time.

 

[coachgeo]

check out Awesomeness signature line. He has compiled alot of the information in here and puts link to them in his sig. line at bottom of the below post (or any other post he has made )

Working on diagram of Cat 3116 common failure points

Working on diagram of Cat 3116 common failure points Please provide input on any other areas that you have found, so that I can add. Open to input from all on this project Will do the 3126 and C7 too, if people provide info. specific to these engines. I may do the drive train later...

www.steelsoldiers.com

still searching for the driveline discussions on the pdf's. they are mentioned in a lot of threads have found so far and a few links given.... but its bits and pieces. will keep searching....

 

[coachgeo]

here you go..... below thread starting at the post linked too....... it is a discussion (with links) of info in the pdf's and kind of a consolidation of information. Am using Google Advanced Search features to find this.

My new LMTV is blowing water pumps and loosing alternator brackets!

I find that Home Depot is hit or miss for the metric hardware for these trucks, but Ace Hardware seems to have a much larger selection (stainless, 10.9/12.9 class fasteners, flanged head, various lengths, etc.). I haven't been to an Ace in years. I would have never thought of looking there...

www.steelsoldiers.com