Hi there,
As far as I know the big difference between M113 and M113A1 is that the M113A1 had a diesel engines vs gasoline for M113.
I think there were some other internal changes (fuel tank? fixed vs demountable?)
BUT what are the external differences? I think it was something to do
with the exhaust pipe, M113 A1 has it in the louvers in the front right
corner but where was it on the original M113??
regards / Robin

Hi Robin

Maybe this would help to spot the differences :

M113 :




M113A1 :


HTH

Frenchy

http://www.inetres.com/gp/military/cv/inf/M113_variants.html

hope this helps'

reb

Hi Robin,

I can't vouch for A1's in service with other nations but I worked on ours(Australian) for quite some time. There was no major external differences to the M113 compared to the A1. The exhaust was still in the same location, the only differences we had was some were fitted with an angeled pipe and others with a straight up flapper type. A lot of our M113 were refitted to A1 which meant that they kept the old inspection plate panel around the fuel filler cap. Later A1 did not have this because of the removable fuel cell.
We sometimes replaced the left rear mudguard with older types that had the half pipe recess in it that allowed the old petrol fuel tank to be drained via its plug in the rear wall but this became rarer as old stock was used up.
The only other differences that I can think of was 1. The replacement of the one piece rear fire wall access panel to a split, two piece (although some did slip through for a few years more notably our M577A1's) 2. We upgraded our T130 track to the beefier T130E1. Visually there isn't much difference between the two unless you know what to look for or have the two different types side by side and 3. because of changing to the diesel which incorporated an alternator, the generator and converter were removed from the drivers position. Please note that I know this was for Australian vehicles as some of the NZ ones we used on exchange still had the generator and converter (AC to DC).

Very long winded I'm sorry and I hope other will share their knowledge as well.
Cheers, John

I can't be 100% sure and I hope someone can clarify this for me too but I believe the radiator was also moved from being under the grill next to the driver to being under the grill with the exhaust outlet. The muffler is located in behind the housing for the radiator mount.

Thanks for the photos Frenchy. I believe the first one to be an A1 and the second a M113. Note the inspection panel around the armoured fuel cover fitted for petrol engines.

Frenchy's picture show the change to the thicker headlight guards. I thought there was a change in the light or horn configuration as well but maybe that was in the A2.

Newly produced A1s with the removeable fuel tank should not have the drain channel in the left rear fender.

Paul

You're welcome. AFAIK, early A1 models (like the one in the picture above) retained this panel as they were fitted with the same "integral" fuel tank

M113 engine bay (Chrysler 75M gasoline engine) :




M113A1 (with GM 6V53 diesel engine) :


HTH

Frenchy

I don't recall any significant changes. My unit had a M577 (CP varient of the M113 with increased headroom in back) that was a gasser that had been modified to diesel. It was the fastest track in the 4th Inf Div. We made a lot of money betting the grunts that our larger, heavier, track could outrun their standard tracks. As far as I could tell, when they changed the power pack they left the final drives alone so we had a higher gear ratio for higher top speed, but less power. Our track was a very early production unit, if you looked closely you could see the weld where the box had been added to the troop compartment for the added headroom.

I found a difference outside the original M-113 to M-113 A1. THE M-113 is a handle unique thick on the front side of the car. In the M-113 A1 they were taken! Why would they serve? because they took? I know they do not serve to lift the car and even to launch the car with a parachute! then, so they were placed in the initial design??? (see photo attached)

that no one could answer today! even the engineers at BAE SYSTEM that are modernizing the M-113 B of Brazil!

I look forward

Got no answer for you but I've noticed earlier test vehicles like the T113E2 have them on a different location :



H.P.

If you are talking about the various squared off/angular bars on each side of the roof, they are guards for antenna mounts. These mounts changed as antennas changed and can be removed or added as needed depending on where you put antennas.

Hi Gino

Here's what Saul is talking about :



On the T113E2, these items are located higher on the front slope.

H.P.

Aahhh!! Now I see them. I missed them before. Sorry, no idea what those could have been for.

IS THAT EVEN Henri-Pierre!! It is this piece even though I'm talking about. I could not put the before photo to show.
Sorry for my english, I'm Brazilian Army Captain and I am an instructor in ARMORED INSTRUCTION CENTER OF BRAZIL. I realized this piece and nobody knows what it is for. It's hard to say that an instructor "did not know" about a particular subject for a student ... so I request support from comrades!

STEEL, BLACK BERET, BRASILLLLLLL!!!!!!!!

I think the engine and thus the exhaust pipe differences are the main differences.

The removable fuel tanks came earlier than the diesel engine I think. You can tell these tanks by the straps that hold them in as well as the lack of rear drain plug on the left rear fender.


I think the engines that come in the kits (TAMAYA, etc.) are usually the older gasoline engine even though a lot of kits give you the option of the diesel flapper type exhaust. Here's my A1 with whats probably a gasoline engine...

Note the upside down Caution sticker on the transmission.. this is what happens when you get older and your eyes can't see as well as the camera! Also - there's a lot of painting touch up that's needed that the camera flash reveled! I wish you could take pictures with a damn 60 watt bulb like I build these things in!

The guards along the top vary according the the radio mountings. They aren't indicative of one version or the other.

I'm suffering thru a set of old eyeballs, but can't see if the tracks in the photos had the "water steer" gear box next to the differential. Looks like they didn't. (really can't remember if it's on the right side or left side to be truthfull). All M113's sent to vietnam had this extra gear box removed as we were told (100%?)

The transmission is different on the M113 verses the M113a1 and later. They look nothing alike, but the one in the Tamiya kit is correct for the M113. The one in the M113a1 is basicly a copy of the GMC Turbohydramatic 400 series, but much beefier inside. Even later they retrofitted them to the X200 series that eleminates the water steer and differential assembly (Iraq?). This one is a scaled down X1100 dash five and similar to the Abrams design (but smaller and a different shape) Note: the X1100-5 was never used in the Abrams, but is a variant of the one in the Abrams.

Also there were at least three different exhaust stacks used on them. One did a 180 degree downturn after exiting the top of the hull.
gary

You forgot to add SPAM!!!

To summarize: late M113 and early M113A1 were externally identical.

Features like reinforced headlight guards, elimination of extra lugs on front armor were introduced to M113 production before M113A1 appeared. Removable fuel tanks were introduced already after the M113A1s were in service.

So the only way to build a M113 model that is clearly identifiable as a gasser track is either leave the engine covers open and use the Tamiya engine parts, or build very early M113 with all its unique features.

One of the external differences btw. the M113 and M113A1 is definitely the exhaust pipe. The M113 (gasser) has the “stove pipe” like angeled exhaust like the Tamiya kit one. The M113 A1 has a taperd one (bigger diameter on the grill area, smaller diameter at the opening) with a vertical seam. In the German WIKIPEDIA is a nice picture of an Israeli vehicle were one can clearly see the exhaust (https://de.wikipedia.org/wiki/M113).
The straight exhaust with flapper appeared first with the A2 version.

Somewhere I heard that the brackets for the towing cable on the first M113 were different to the later ones (left/right vs. top/down), TAMIYA has the early ones.

Also, the early M113 have had a different trim-vane top bracket, it was narrower than the later ones.

All in all it seems to me that TAMIYA has a M113 gasser with their old kit.

Could these brackets be for fixing a dozer blade?

In the Squadron/Signal M113s in Vietnam, on page56 they show a mine clearing device attached with brackets like these. Also, on page34 is an ARVN track with them. And on page3 it says they were lifting or towing eyes, sometimes found on early ones.Also page16 the second track has them.
Wayne

I don't think so. The dozer blade mounting brackets location and shape are different :



I would bet they're lifting eyes. The T113E2 prototype had four of them, on each corner of the hull :



H.P.

Simple lifting eye later replace with the bolted on version. Looks to me the eye cut as part of the side plate and not wielded on later. Since there are several different location the builder was testing several location before going to the bolted on version.

Another thing-more a crew thing is the safety pins added to the driver hatch, TC hatch and troop hatch. This was a simple bracket with a pin (Like on the .50 mount) which kept the latch/handle from popping up and unlocking the hatch. I was detailed to drive a TOW track in the RoK, and we were in a overwatch position at night. Anyway (Yeah, yeah we were busting nose-sleeping) runner comes up to the driver's hatch, where else, and tells me to start the track the company is moving out. The RoKs have a lot of pre made fighting positions, and since my TC was to lazy to ground guide, I had to flip the vehicle around to get ready to move down the road. I can't recall if I used my pivots but anyway, backing up to line up, my track hit the berm, the latch unlocked on the driver's hatch came down on my head, then the .50 barrel swings round (Tired ass TC half asleep in his hatch) so now we are going down hill with my right arm stuck outside the track because my arm is trapped by the hatch, and the hatch is being held down by the .50.
Anyway, I rotated to Ft Benning and my recollection is sometime during the summer of 77' some body got caught with the detail of putting the latch pins on the tracks. The other change would be dome lights from red to blue, that would be late 80's. The stickers with the guy on them that is A3 stuff. All the tracks I was on had pivot steers to include the A3, which you just shifted into steering lock, and then the T Bar acted like pivot steers. For some reason our battalions' track pivots at Ft Benning, where disconnected then we reconnected (They were safety wired away from the pivot brakes connectors in the engine compartment)them. In our case we had to have ours reconnected because I was in CSC with 4.2" 106s and we needed the pivots for large deflection changes because the turn table had stops to prevent the tube/cannon from rotating to the point (As I was told) where it would damage the torsion bars if fired. The 81s m125 had 360, but we never fired anywhere near that. Later the whole battalion re hooked up their pivots to swim the tracks. Forgot the floor plates-in between the floor plates (really under) should be black rubber gaskets, when these are missing you will see the lt porta potty green colour the Army likes to paint the insides of tracks with. So in between the floor plates in the back you should see either green or black. In side of the road wheel, there is a molded space, for what ever reason which goes all the way around, when you play army, mud always cakes up in there, but when you clean it out the metal is unpainted. Another thing I think on the A1 the Army replaced oil fittings with grease on the road wheel hubs. So at times you would see these grease tails on the road wheels when someone greased them up. Also a lot of things were retroactive like the pins and the grease fittings, so earlier models would be upgraded. I drove a gasser M577, and it had the new fittings and the safety latches.