Gamma Goat

[rickf]

A little tidbit on the nomenclature of a Detroit diesel engine. The numbers tell the whole story on the engine. A 3-53 has 3 cylinders and 53 cubic inches per cylinder. I am sure everyone has heard of a 6-71 Detroit? 6 cylinder, 71 cubic inches per cylinder. They had the 53, 71, 73 series engines and many different cylinder configurations. 3, 4, 6, 8, 12, 16 cylinders. 16 cylinder engines were pretty much for mining trucks and stationary engines.
Mr. Recovery surely remembers the 12V71 Diamod Reo and Brockway trucks! I drove both, The Diamond Reo was a heavy haul tractor and the Brockway was a tri-axle dump truck. They were screamers. They were very thirsty and definitely not emissions friendly.

[Hambone]

Went and hung out with Blake @ Red River yesterday, told him we had a member that just acquired a goat, he said he had already talked to you, he probably has what you need in the goat market. We found some more panels for the 151, it's what I would call the kick panel, the one that goes under the clutch/brake pedals, also found some spare tire mounts, he's getting some cool stuff over there.

[1SGCAV77]

HaHa. I had same thought. Beer cans. Recycling over and over. Maybe should get some of those red, white, and blue camo beers TV is advertising. A monument to the Goat.

[acudanut]

You can hear a Gama Goat coming a mile away. lol.

[m3a1]

Yes, Blake was very helpful and remarked that I would do far better by providing him with parts numbers. I'll be digging in the books for those, let me tell ya!

Hambone, if I had known you were that close I would have certainly made an effort to stop and say Howdy.

I stopped at Turner's in Hooks, Tx and grabbed a few things (misc straps and a roll of cotton strap webbing, mostly, and a mil-spec shovel that is desperately in need of being sandblasted). It probably wasn't worth bringing home but, who knows? The way things are going, Turner's might not be there the next time I get up in that neck of the woods. Because it's only four miles from the Arkansas/Texas state line, I don't exactly get up there very often.

Turner's is not what it used to be but what old school surplus store is? Times are a-changin'... I couldn't even get in to see their father's personal museum which was dark and locked up tight. But, even with el 'Rona and the fading business, their passion for all things green still remains. They came out and took pictures of the goat and I hope I at made their personal wall of fame at least.

Here is how I looked, rolling out of Louisville, Ky. Baby is no slouch. She handles the Gama Goat with ease.

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Okay, enough about that. Let's talk Gama Goats! To kick off the upcoming wrenching session, I thought I might begin with a photo taken from the March 1977 Operator's manual just to get everyone oriented as to the operating controls.



I will give you cats a peek of the actual controls. By the way, I have a new robotic assistant. You may see him once in a while, working in the background.

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There will be some minor reclamation efforts in the crew compartment along the way. Among them, certain fasteners that need attention, a little effort on those lube points as I come across them and maybe even a tidy-up here and there. I think I can improve my personal fahrvergnugen by doing a fee extra things while I'm in there.

I realize the little stuff doesn't get the throwout bearing sorted out (if it actually is the throwout bearing) but I've found that it's best to tip-toe up to the big stuff and take care of the housekeeping chores along the way. Leaving the minor stuff for later just becomes another job I have to think about and I need every brain cell I have left available for working on the the major fixes.

In local news, our local Christmas bacchanalia and parade has been cancelled due to el 'Rona so there is no schedule I will have to adhere to in getting the Goat ready for any event in our immediate future. Can't figure out if I'm happy about that, or sad. Life is giving us lemons at the moment, so I'll make lemonade and use the extra time to advantage.

[m3a1]

Here are my controls.

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[Hambone]

I live about 2 hours east of Blake, you passed right by his place, few exits west of Turners, I think 206, I visit him several times a year. Don't you live close to San Antonio?, my sister lives there, I visit her a couple times a year, maybe we can have a cold beverage on my next trip. I would like to have M792 goat ambulance, look, this one swims.

[m3a1]

Now, while I gut the crew compartment, let's compare MUTTs and GOATs.

The biggest difference is the construction of the workspace. A MUTT is largely wide open, whereas a Goat is a bucket on wheels. So everything that happens with a Goat begins and ends with climbing over the sides.

Both vehicles have two seats up front, both of which are removable by taking out two pins. Like the MUTT, those pins are up front but the Goat's pins are crafty little high-speed, low-drag buggers, which not available at your local Tractor Supply. The major difference between the two is that Goat seats are extremely light in that they are constructed of aluminum tubing with a fiberglas seat whereas, MUTT seats weigh a ton. But MUTTs are designed to sink and Goats are designed to float.

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Another difference is that the Gama Goat has only one adjustable seat, it being for the driver. It adjusts fore and aft (I'm using nautical terms since the Goat is (a) amphibious and (b) issued to the USMC ). The adjuster is a track with a spring loaded catch exactly like an automobile but with a ridiculously large knob that is impossible to miss. You certainly don't have to go hunting for it.

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Here are the pins.

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This will give you a sense of how the frame of the seat is constructed. This commander's seat has no adjustment.

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To remove the seats
Step one - remove the pins and raise the front of the seat up and out of the front tracks in the floor.

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Step two - slide the seat forward approximately 1". This brings the rear 'legs' out of their track.

Step three - lift the seat up and out. This process is certainly no harder than performing the same task on the M151.

[m75]

I know it's not M151 stuff, but I really like this thread so far, especially the developmental background.

I drove everything in a Mech Infantry battalion between 1973-1978, from M151 to M561 to M35, M114 to M113 to M577 to M106/125, and finally M578 VTR. But I will state without reservation that the Goat was the most memorable, off-road capable, and NOISY critter that I had the pleasure to operate courtesy of Uncle Sam. When driving a Goat, you didn't get there in a hurry, but you got to places that most other forms of transport (save helicopters and leather personnel carriers) couldn't. I always wondered tho why another, more practical engine was not brought into play. By practical, I mean conventional I guess. The Detroit Diesel three cylinder, two-stroke motor located immediately behind the driver gave emphatic meaning to the dashboard warning that Hearing Protection was Required!

[m3a1]

The next step in the process of gutting the crew compartment is the removal of the transmission tunnel. It is constructed of fiberglas with a wall thickness of 1/4" and perhaps a bit more here and there. It is fastened to the deck with several bolts on each side. This process begins with lifting the engine cover and securing it with the control arm on the passenger side and the prop rod on the driver's side. More on that matter in a bit.

Next comes the removal of the shift knobs, releasing the clip for the control lever for the winch power take-off control lever, placing the trans brake lever to the engaged position (straight up), removing the boots for the transmission and trans-brake controls.

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Then comes the removal of the various access panels from the tunnel. These panels are not generous in terms of their size, particularly when on is kneeling on the deck of the compartment. It is my understanding that these were not part of the original design. If that were the case, these would be a retrofit. It is highly likely this particular USMC Goat was one of the original batch that went directly into storage when design inadequacies were brought to light.

The matter of routinely checking and possibly having to add fluids could not have been a popular task. The job was not impossible, mind you, but I can assure you it was no one's favorite thing to do. With the seats removed there would be adequate space for these tasks but there are all sorts of things sticking up on the deck which make getting down on all fours a bit of a dicey proposition.

I'm guessing the solution the maintenance guys came up with was a wood decking plate they could toss in there; one that had some wood supports so as to allow the floor to lay over all those things that were sticking up. Such a thing would make a temporary work surface that made the floor flat, smooth and unobstructed. This is pure conjecture on my part but if I were spending a lot of time working on these, having one for each side would be a huge bonus and so, creating such a thing is on my to-do list. Imagine inadvertently kneeling on one of the seat tracks. OUCH! No thank you!

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Next is the removal of the transverse member of the rear bulkhead of the crew compartment. It has many fasteners for the canvas cab roof (which are fragile). Four bolts with fasteners incorporated into the member are so located that they are easily accessible by standing alongside the vehicle.

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Lift the transmission tunnel up and out. This is a one-man lift. The tunnel is 37" long and 20" wide and very easy to handle without assistance.

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[m3a1]

Thanks for commenting, Jim. The real theme of the Gama Goat that seems to have gotten lost over time was that it was expected to be able to keep up with tracked vehicles and big guns. And yet, that that idea seems to have gotten lost over time as the M561 fell into more mainstream use.

For a moment, imagine the Gama Goat as a vehicle that had no need to swim. If it had been relieved of that sole requirement, much of the hull that made the Goat so difficult to maintain would not have been there and, noise notwithstanding, if had only been a dry-land critter, then they would have really had a machine that everybody wanted to have... and the Goat would have an entirely different reputation.

[m3a1]

I know Rick has been waiting to see this so I'm going to post this one photo and get back out there. This rest & relaxation period has gone on far too long.

I know this looks complex but it's really rather simple...

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[m3a1]

Well, the old girl is all sorted out. I don't know exactly what I did but whatever it was, it seemed to fix things. It would be nice to know...but some of these gals like to keep a few secrets to themselves.

So, I got a drive in around the neighborhood this evening and rattled a few windows. I'm sure everyone is properly all in a tither. It will be fun to get the horn working, just to add to the noise.

Hopefully tomorrow I will get the power washer out. lay on the degreaser and clean out the carrier and try to sort out the oil spots from the spare engine. The tractor can remain greasy down in the bilge, for all I care. Just think of it as a layer of anti-corrosion. Big, or little, Detroit Diesels are notorious slobberers. Oil draining into the engine's air box has to go somewhere! I'm okay with that because, after all, Gertie is dirty....bless her heart.

I promised to get back to the matter of the engine cover so this will be straight and to the point. Early production Gama Goats came with an engine cover constructed of aluminum. Mine is one of those early Goats. The engine cover is a square-edged, rather boxy affair and not nearly as racy-looking as the later stamped steel ones with the radiused corners. Those are far better looking and far stronger. Aluminum is nice stuff but it is rather brittle which brings us to the matter of how to open, and secure an aluminum engine cover.

No matter how light-weight aluminum is, get enough of it in one place and it becomes rather heavy. Designers added a torsion rod to assist in the lifting.

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But, if not properly supported, even the most artfully constructed aluminum box will begin to crack at various stress points. There is some minor reinforcement at the corners but notice that there are no gussets. Add to this the weight of the windshields which store in a special storage box which has been skillfully worked into the design of the engine cover and now we're talking about some real weight. This cracking was a problem with early Gama Goats...so much so that Uncle Sam and the Commandant of the Corps directed that the process of opening engine covers on Gama Goats was to be a two-man job.

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And, with the engine cover up, now we have the issues of torsion in the box if left unsupported on both sides over long periods, not to mention the vagaries of weather because, while open, the engine cover is a great big sail. In order to stabilize the cover while up, a prop rod was provided on the driver's side.

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A lot of weight was trimmed from the Gama Goat, particularly in those areas above the center of buoyancy. Evidence of the designers efforts to keep the weight low as well as centered on the machine can be found everywhere. This contributes to stability on land as well as stability in the Gama Goat's second home - the water.

By the way, I made good on my comments about making the decking a place easier to work on... Far better than stomping all over those seat brackets, let me tell ya!

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But at the moment, it's bed time for Gertie. She definitely needs her beauty sleep!

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Cheers,
TJ
"This is my Gama Goat. There are many like it, but this one is mine."

[12Bravo]

The horn used to work , ignition switch must be on. Spray it down with WD 40

[rickf]

And I see already how you access the throwout bearing. Great as long as you only have to reposition it but replacement looks like a bear to do.