• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

 

LMTV M1078 Tachometer

lmtvjunky

Member
56
4
8
Location
Auburn/California
Hello to everyone here, it's a pleasure to meet all of you and to enjoy all the experience and knowledge of military vehicles. I have a question about installing a tachometer in the M1078, not too many trucks had them and I'd like to do an install. Without splitting the engine from the tranny, does anyone have a flywheel or a separated engine to get an accurate tooth count on the flywheel?
I purchased a couple magnetic sending units, both single and duel outputs, there's is already a magnetic sending unit in the bell housing and another spot for one more but it's being used for a vent, which can be rerouted. Any help would be greatly appreciated. Also I am going to start posting a whole lot of pics and threads regarding these trucks. I have 6 trucks now and 4 trailers, I've picked up a ton of random parts now and want to share my experience of working on these trucks. Erik
 
Last edited:

NDT

Well-known member
Steel Soldiers Supporter
10,106
5,712
113
Location
Camp Wood/LC, TX
Welcome LMTVJunky. Steelsoldiers is turning into the go-to resource for FMTV troubleshooting, and your contributions are welcomed! Try to post lots of pics and civi-equivalent part numbers. Dig around in the "P" suffix TM's, you will be able to determine if the winch trucks had a different flywheel (I don't think so) and where the magnetic pickup is.
 

Suprman

Well-known member
Supporting Vendor
6,832
645
113
Location
Stratford/Connecticut
Probably piggybacks off the trans harness somehow. The manual dosnt show a different harness for winch trucks so there is a good possibility the connection you desire is tucked away somewhere in the dash or behind the heater. Pic below is what the connector should look like. A tach signal should also be included in the big round ste ice diag plug to the left and down from the steering wheel. The manual shows diagnostics determining engine rpm from there. The A1 winch trucks do not appear to all have tach's. Maybe since the engine is electronic control the system auto-sets the rpm for winch operation.

Instruments. The Instrument Panel includes all gages that provide the operator with information about vehicle
condition and operating status. The speedometer (1, Figure 1-13) receives electrical input from the WTEC II Vehicle
Interface Module (VIM) on vehicles equipped with WTEC II transmission controls. The speedometer receives electrical
input from the WTEC III transmission ECU on vehicles equipped with WTEC III transmission controls. The WTEC II
VIM and the WTEC III transmission ECU are both located behind the kick panel. Tachometer (2) input is provided by
the engine speed sensor located on the engine flywheel housing. The fuel gage (3), oil pressure gage (4), water
temperature gage (5), front brake air pressure gage (6), rear brake air pressure gage (7), and VOLTS gage (8) receive
electrical signals from sending units. The sending units respond to changes in fluid level, pressure, temperature, and
DC current and send this information to the gages.
1-18


DSC04702.jpg
 
Last edited:

Suprman

Well-known member
Supporting Vendor
6,832
645
113
Location
Stratford/Connecticut
The A1 winch truck that I have did not have a tach. I believe this is due to electronic engine rpm control. Less operator options.
 

Johno176

Member
71
5
8
Location
Oakland, MI
Suprman: I'm going to install a hydraulic package (pto/pump, tank and winch) on a non outfitted A1. Am I correct in assuming the wiring harnesses are all pre-wired for this option? If so, then by hooking in all the components does this complete the circuit to let the ECM know to adjust engine rpms. Thanks, John
 

Suprman

Well-known member
Supporting Vendor
6,832
645
113
Location
Stratford/Connecticut
I dont have much A1 experience my A1 truck has collision damage. I believe there is a trigger lead that kicks up the rpms with winch engagement after the pto is engaged. Matt in MI has a complete winch setup he listed for sale it is a first gen though. The A1 manuals are interactive on the diag computer. I can prob ask someone to run thru the winch problem flow chart it should tell which wire to check.
 

Keith Knight

Well-known member
Steel Soldiers Supporter
699
1,460
93
Location
Wauchula, FL
To answer your original question I have a 2004 transmission waiting to go in my 2003 LMTV and the tooth count is 134. I'll try attaching a photo.....I tried with out success.
 

Suprman

Well-known member
Supporting Vendor
6,832
645
113
Location
Stratford/Connecticut
I am in the process of pulling a trans right now. It's larger and heavier than I originally thought. Unless you are lifting it out the top I am thinking a very large transmission lift would be in order. I measured the trans I am thinking either the truck has to come up a few inches or the trans has to come down then shift sideways slightly to clear out from under the truck.
 

Keith Knight

Well-known member
Steel Soldiers Supporter
699
1,460
93
Location
Wauchula, FL
If I could figure out how to post pictures "MacBook" I would show you the cart I made to lower the trans onto then roll it out on the passenger side after also removing the muffler. I built it as low to the ground as possible to clear the frame. Lmtv722 and I removed the one I have and we dropped it down then slide it out. Also in one of the tech manuals near the end shows how to make a lift bracket that bolts to the transmission that you can lift it from a single point and is properly balanced.
 

Lmtv772

Banned
651
18
0
Location
Florida
That's how I did it. hooked a couples of slings to the the transmission and our front loader. removed the transmission bolts and lowered it down on a pallet. It was a bit easier , since the engine was out already.
but be prepared, It's a big hunk and is pretty heavy.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks