Difference between M998 and M998A1 & Engines

[erasedhammer]

So I cannot find anywhere what the difference is between an M998 and the A1 version. I notice the weight of the vehicle was increased by 180 lbs. So what did they add?

Also, I saw that 1982-1993 humvees and hummers used the 6.2 NA, and 1994-2004 that its all 6.5 NA's and Turbos. So my vehicle is a 1994, but it was advertised on govplanet as a 6.2. Did they still put 6.2s in 94 humvees or is that a mistake? Where are the markings on the engine to determine the engine displacement?

 

[Joehop]

To determine if you have a 6.2 or 6.5 you need to remove the inside engine cover and look at the oil sending unit, If the hold down flange is on the left then its a 6.2, if its on the right then its a 6.5

 

[Lionel]

From AM General's site;

"A1 advances incorporated across the new production fleet included: new front seats, improved parking brake lever with safety release, metal hood grille, improved slave receptacle, solid state glow plug controller, modified rifle mounts and upgraded rear half shafts."

I know my '94 A1 also has the brake upgrade that incorporates the parking brake into the rear calipers, eliminating the propeller shaft disk brake. But this was apparently done at the "reset" for any 998.

 

[juanprado]

Just curious as to what was different with the slave receptacle and what was different with the rifle holders as I have only seen one style of each and was not aware of any differences?

 

[Action]

So I cannot find anywhere what the difference is between an M998 and the A1 version. I notice the weight of the vehicle was increased by 180 lbs. So what did they add?

Also, I saw that 1982-1993 humvees and hummers used the 6.2 NA, and 1994-2004 that its all 6.5 NA's and Turbos. So my vehicle is a 1994, but it was advertised on govplanet as a 6.2. Did they still put 6.2s in 94 humvees or is that a mistake? Where are the markings on the engine to determine the engine displacement?

Humvees were not inproduction in 1982, and 2004 was not the last year.
As far as you driving a 1994 with a 6.2. That is entirely possible, because it could be a new data plate with the wrong year, as many of the GP Humvees have.

 

[erasedhammer]

Humvees were not inproduction in 1982, and 2004 was not the last year.
As far as you driving a 1994 with a 6.2. That is entirely possible, because it could be a new data plate with the wrong year, as many of the GP Humvees have.

I got that information from wikipedia, so it could be wrong. It had two dates 1994 to 2004 and 1994 to present.

Is there any way to tell the age of the vehicle if the data plate is wrong? Currently I am unable to register the vehicle at its current age, but if it was 3 years older I could register it as an antique vehicle.

 

[Lionel]

"and 1994-2004 that its all 6.5 NA's and Turbos"

From what I have determined, Turbo's did not come off the production line until 1996 and after.

 

[Action]

You have to use what is on the data plate. It isn't supposed to be on the road, anyways.
The serial number would help to get a year of production, but I haven't seen a list of cut-off numbers. There is a post on this site where the guy will get you info from your VIN.

 

[Lionel]

A link to your truck so we can take a look may help.

I got that information from wikipedia, so it could be wrong. It had two dates 1994 to 2004 and 1994 to present.

Is there any way to tell the age of the vehicle if the data plate is wrong? Currently I am unable to register the vehicle at its current age, but if it was 3 years older I could register it as an antique vehicle.

 

[erasedhammer]

Heres a link to a google drive with some photos of the data plates and the vehicle.

https://drive.google.com/open?id=0B2qtBa6UyYjXYUFMVnJqeDI2MUU

 

[alpine44]

To determine if you have a 6.2 or 6.5 you need to remove the inside engine cover and look at the oil sending unit, If the hold down flange is on the left then its a 6.2, if its on the right then its a 6.5

There is an easier way to tell whether the vehicle has a 6.2L or 6.5L engine. Look at the coolant crossover and compare the connection to water pump.

 

[gcbennet]

This is a table I found published in the HMMWV Modernization Plan by RAND. I'm not sure how accurate it is, but this company contracted by the DOD seems pretty thorough with their info gathering.
View attachment Mfg Date SN Table.docx

 

[gcbennet]

View attachment HMMWV Modernization Plan by RAND.pdf
Not sure if this will work, but here's the whole RAND document.

 

[erasedhammer]

This is a table I found published in the HMMWV Modernization Plan by RAND. I'm not sure how accurate it is, but this company contracted by the DOD seems pretty thorough with their info gathering.
View attachment 646209

Ny data plate seems like it was never replaced or tampered with, but my vehicle has a SN beginning with 153 and the delivery date says 04/94.

 

[brazengoat06]

just bought my first M998A1 from GP. I did notice that its advertised as a 95 but has a 6.2 with 1990 on the emissions exemption label. Not sure what thats about. Thought maybe they just swapped motors from a 90 model.

 

[desmodromic]

I have a 1995 A1 with a 6.2 also. My assumption was that AM General stuffed a left over 6.2 in there, but it is just as likely the motor pool did it at some point. It has all LED lights and the 210 amp alternator FWIW.

 

[brazengoat06]

I'll upload some picks cause I have no clue what I have

 

[brazengoat06]

how can i determine if its even an A1? I realize what was changed but not sure how to compare to know exactly what to look for.

 

[brazengoat06]

.

 

[86humv]

That master cylinder only came on A1's and up.