I have a feeling those mysterious gear teeth are from a previous catastrophic failure that wasn't cleared out before being replaced, or were left to make a speedy recovery in the field then forgotten about, before being parked.

Those teeth (my guess) are from a starter Bendix gear that was smashed from all that slop in the main bearings. Very interesting watching to dismantle something I'll probably never even see. Thank you Matt

Hey Matt - I worked for a large Caterpillar company in Denver, CO in the early 70’s. (I am 81, now). I worked on a lot of D8 Cats. We changed out the pony motor as an assembly and never got the chance to tear one apart. Very interesting.

BEFORE Diesel Creek I had NO idea what a pony moter was, and never even operated any piece of the sorts of equipment Matt is doing.(I'm a computer guy) NOW I own a tractor, bought a farm, and are fixing all sorts of duhdah's for whatever i need to get by, inspired by Matt and others like him. GREAT content !!

a small gear like that, my guess is that it came from a broken starter that since have been replaced.

I will never, ever need to know any of what Matt tried to teach me today, but strange as that is I could not stop watching this. The flywheel slop was epic. These episodes are why you have 3/4 of a million subscribers.

In all my years of rebuilding engines of all sizes, I've never came across one with that much wear that still ran. AMAZING! Thats why those old Cats just keep on going.

What I love about this channel is how you always steam clean or pressure wash an item before you start to video. That removes the blackened grease/oil sludge from the working surface and allows much better video content.

I believe the teeth were from a failed starter bendix that never was retrieved when they had the initial starter problem Matt. The size and number is similar to the teeth count on the bendix.

Matt, at around the 10 minute mark you explain why you save old junk like this, but there's a neat side-effect of what you and those of use who care about old stuff do: there's a "gap" generation around old equipment where the old codgers who worked with it every day start to retire and pass on and the new kids in the field have new, high-tech fancy stuff and don't need things like pony motors &c., so off they go to collectors or the scrapper. With luck it's to a collector, and with greater luck still it's to a collector that will use it and instruct others in its use--like you're doing right now in this video. When these things pass out of every day use and into the "antique" world, there's a risk that they themselves as well as the understanding of their use is going to disappear forever. Think about steam engines, and how a whole generation of teachers were mostly lost before the nerds picked it back up again. All it takes is a generation of folks going "I don't know WTF that does" to lose that real-world, practical knowledge of the thing. Great example is live steam, which in the UK is SO MUCH more robust than here in North America. Why? The Brits took forever to switch from coal, we didn't. And that switch just so happened to coincide with folks starting to wake up and realize that it's worth saving the old stuff, even if it's not "useful" in a conventional sense anymore. Like a CAT pony motor. :) Thanks for giving a hoot about the old iron, Matt--preservation and conservation is a gift to future generations. There's always "a million of them" out there... until there isn't. Good, old machines deserve to be saved and ought to be put to work. They might be the only things that actually last in our age of emissions equipment and computer-controlled common-rail injection. Cheers, and I hope you and your pod have a happy Easter weekend. 🐇🐇🐇

From an expert ‘ole cat skinner’ who has gone to the dozer home in the sky: after you start the Diesel engine, disengage the pony, but don’t kill it. Turn off the gas and let it run dry. That warms up the pony, drains the carb, and your pony cast iron warms evenly to fight dampness. I pulled down my D7-3t pony and found a shop that could weld up and grind the crankshaft back to spec. We had to bore the cylinders off center to get them round again. My 3T was dry clutch so the previous owner managed to beat on the bendix with the canvas-and-sheet metal links that break in the dry clutch. I found bendix parts from a 2U in a junk yard. Be thankful for your oil clutch and be assured it could be worse.

Regarding the grey/silver sludge, I didn't see that anyone suggested it is actually LEAD from leaded gasoline. We used to call it grey paint. I was an apprentice car mechanic in the 60s when leaded gas was the norm. The grey paint would get so thick in the oil pan it would plug up the oil pickup. When removing an oil pan with that in it, it felt as heavy as if half a crankshaft was there. With the age of that pony engine, it likely ran most of its life with leaded gas.

My take away from watching this is pure amazement with the engineers who designed and manufactured that whole assembly pre computers. I can't imagine the cost to make all the tooling to cast all those different pieces in an economical way. Mind blowing to me.

Fascinating teardown! The crankshaft bearings on these ponies are commonly ruined by a leaky carburetor valve: if the fuel shutoff isn't used and a tank of gas drains into the oil, the oil becomes useless. Just a short runtime with ruined oil will trash the crankshaft bearings.

I am an IT guy from Germany. So I could not be further removed from this topic, but yet still I love watching these videos. Keep up the good work of reviving old steel that others have left to die. Also very nice to see your channel frow over the years, almost at the 1 million mark now, great :D

I agree with the mystery teeth coming from a previous starter catastrophic failure. I have never been in a position where my (and possibly my family's) next meal depended on me getting a piece of equipment operating so I could finish a job and get paid. The pressures of life and the mindset of someone who doesn't perform recommended oil changes and would also leave gear teeth inside a gear case is something I cannot relate to in any way. Matt has clearly established that neither the motor or the gear case received recommended maintenance and that the carnage occurred because of the wear on the engine main bearings which was due to oil that was filled with abrasive particles. Maintenance is not done for various reasons. I know/have known people that can always find money for beer and smokes but can never find money for oil changes. If every machine owner put maintenance high on the list of important things Matt wouldn't have a channel. Without so many mistreated machines we wouldn't have such entertaining videos illustrating the effects of that mistreatment.

Wild guess s those teeth were from a part that was replaced? Something stripped the teeth off, maybe the starter? They replaced the starter but didn't pull the whole thing open to gett he bad parts out

Love how you can drop a pony on your ‘new’ bench with a forklift and it doesn’t even flinch 👍

20:16 Look at the flywheel teeth. That's where the "gravel" comes from. Thanks for sharing !

I own a tree service company and am from the city so naturally without much mechanical knowledge I would just send my trucks and machines to my mechanic, after watching your videos for the past year I always try taking a crack at it myself now, saved myself so much money and have learned so so much from your channel, thanks for the awesome content Matt, love and respect from southern Ontario, Canada!

Wouldn't be hard to braze up that gear case. Worth saving. Doesn't have to be difficult. Prep the weld seem. It doesn't have to be huge. A 3/16 v is enough. Drill holes at each end of the crack. Build a nice big wood fire and get it all hot in some coals. Keep it in the coals while you heat up the joint and braze it up. Finnish by building up the fire a bit to bring it all up to an even heat. Cover it all with the coals and ashes when it dies down so it cools slow. Leave it till the next day. It sounds like a lot, but really isn't. Most of the effort is building a bonfire and watching it burn.

That pony motor was rebuilt 5 months before I was born. My parternal Grandfather ran those Cats back then, but in the other side of the country. He was about my age then too.😊

Absolutely amazing! Thinking of the time when this dozer was built and the machinery they had to work with, it always amazes me with their final product. Today we have modern CNC equipment that can do amazing things but back then it was a lot of ingenuity, that can only be admired!! Keeping in mind this was only a small part of this dozer!!!

The gearbox assembly is toast, but what about doing a full rebuild on the motor unit? What about a colab with the other awesome UKposts JimsAutomotiveMachineShop? Would be amazing to see that motor brought back to fresh!

I'm so glad you posted a video today, because the 10th. of this month I was on my death bed, but I barely pulled through and it seems that each day now is a Blessing, but I'm still very weak and very limited mobility from this awful Flu I caught from my Grandson that he got at the Daycare. I hope I get to see more of your videos .

The gear teeth look like they may have come from an old starter Bendix that might have dynamited at some time. Most likely from the flywheel being as it is. Amazing that this engine still cranked over. Love the old iron, they are almost indestructible. No engineered obsolescence.

After rebuilding starters and alternators for the last 40 years that appears to be the remnants of an opinion that came apart from a previously installed starter

Love the baby T-Rex shadow on the work bench around 10min mark

"new" forklift??? Did I miss that video? 🤔🤔🤔

I had a cat12 grader with a 2 cyl boxer pony. Pony threw a rod, broke some pieces out of the bottom of one of the cylinders, so I left the bottom oil ring off on reassembly. CAT dealer didn't want to mess with it which they told me by offering a ridiculous amount of $$$ to even look at it. Also got into a contention between CAT and auto shop as to who broke the end housing getting it off the crank, but CAT made it good with another from their boneyard. New pistons, rings, rods and bearings and it ran like new. Thank goodness for their boneyard, I also needed a steering knuckle for that machine. Apparently it's common for the spindle to fatigue crack, because mine cracked through, and the first one they got me was also cracked in the same place. The first spindle failed a bright early new year's morning, then broke the spindle on my case 580B trying to get the CAT12 off the runway, all before noon. Which goes to show you don't do ANYTHING before eating your black-eyed peas New Year's morning!

I’m thinking those teeth are remains of an old starter or gear that failed at some point and was replaced. Just shrapnel that was left behind. 🤷‍♂️ I sure do enjoy watching these videos and appreciate you bringing us along. Thanks Matt.

A friend of mine, when he knows he is replacing parts that have cotter pins in them, he does not even bother with pulling the pins. He makes sure they allow his socket onto the nut and he spins them off with an impact or breaker bar. He doesn't care what kind of damage the pin may cause because, the part is being replaced. If he is not replacing the parts, then he will be careful and he uses a new pin every time. I tend to remove pins just to keep a running inventory of what came apart and what needs to go back together.

Have a beautiful Easter everyone!.

Hello Matt, One of my most watched channels (after yours) is 'Squatch253'. He is a Caterpillar nut. He has rebuilt many pony engines from scratch always with great care and finesse. I know that He could help you to either repair or replace all things Caterpillar. He has always amazed me when it comes working on any project that he endeavors. Give him a shout. Sad to see the results of a neglected engine. Great video, Thanks.

That gearbox case looks like an ideal candidate for you to practice cold stitching on. Check out the guys from Tinkering with Tanks and see them repair a cast iron block. You never know when you might come across a really rare engine that you can't just swap out casings on. Love the content Matt

It's pretty awesome when you find metal that's the consistency and texture of CLAY under a gasket.. WOW 16:10

Nice morning, Coffee and Diesel Creek with Matt.

Matt , the time and investment in your super heavy duty work bench sure has paid off! It handles the weight of that Pony motor like it was nothing at all.

The engineering that went into that motor alone must have been huge. Glad Matt took it apart for us mortals to see.

Thanks Matt, I enjoyed your exploration of the pony motor. Add that to your knowledge, you already are a master of your craft!

loosely assemble it back in the case for storage, protects and takes up less space than all the bits spread out.

I have a difficult time imagining how the heck the design engineers come up with the designs to make these things work together.

It's the wizbanger gear connected to knuten slide shaft. Really look at side of the gears.

Great video love see how the old machines work. Glade to see your still interested in keeping them working good job

Hey Matt. I’m quite sure if you match those pieces up to some of the existing intact gears you will find the origin. My guess would be the starter drive. What I’m trying to say is that the pieces have been laying in there from some previous failure that you wouldn’t have any way of knowing about. There’s no telling how many starters have been on that pup over the years.

Thank you for putting the diesel creek sound track back on

Very cool little motor and the machining that goes into building those engines back then is just plain awesome!!

Best Shop Teacher for Heavy. Thanks for the lessons!

Semi SuperVillans knock it out of the park with their music !! LOVE the opening music!!

You need to have that workshop crane installed. Look forward for the video 🙂

This is my go-to channel alongside Marty-T from New Zealand, Ants Pants from Estonia and Kris Harbor Natural Building from GB. Aways makes my day when these guys are dropping new content.

Compare the shrapnel gear to a starter Bendix gear. At some point in its life it may have had an Old exploded starter from the crank bouncing around, The starter being replaced and you running it long enough to free the parts up from the sludge.

Nice way to showcase all your new toys! I have been watching for years. Happy for your success. Thanks for the in depth view of the pony motor starter system.

Drill both ends of crack with oh 5/16 drill bit. Then preheat case to 450 then weld with nickel rod then but case right back in oven still on 450 then over hours slowly bring temp down slow slow if to fast it will crack

As a retired truck mechanic 32 yrs. I have never seen a crank with that much play in it. Hard to believe that it was running that way. Great vid, love your content.

Now it's nice and clean it seems a shame not to rebuild it. Use those gear teeth to cast a new cog and a bit of gaffer tape around the crack on that housing, and grease up those bearings. It'll be good as new.

Good times. Lunchtime in the UK with Diesel Creek. Epic.

I really enjoyed the tear down of the "Pony Motor." It's really great seeing you use your newly built shop whilst you do this kind of work. Well done, Matt!

Thank you matt, another great view into the guts of a motor, none of that looks too bad, the bearings havn't run through to the case, metal paste I just wear and lack of oil changes. The spare teeth look to be starter motor sized. In the past with units like that, that I have kept for parts I loosely assemble the unit so it's all together with grease on the good bits and a list attached. Sometimes a stand so it's easy to move. I would keep the gearcase to and let someone practice fixing it. Bye!..

I had to re -shoe a caterpillar pony once , so many legs by the time i finished I had to start again 😅🍻

Matt, If you choose to weld that cast iron here's a tip. My Dad a fleet diesel mechanic who would be 102 ys now, would take an acetylene cast rod, strip a elecrtical 14 ga wire, wrap it in 1/4 inch wraps, drill both ends of crack, rose bud the cast then dip flux and weld one inch strips from each end till welded. This allows hot welded cast to be softer and more flexible. This is especially good for manifolds. Don't forget to bolt down a manifold so it doesn't warp. Hope this long winded story helps you some where along the way.

Thanks Matt for the tear down on the pony engine 👍 Old F-4 Shoe🇺🇸

Great show! I like seeing how things [used to] go together!

That babbitt bearing was probably a poured lead job which would explain why the metal in the bottom of the pan is so fine.

I hope you have at least some experience of "hand cranking" engines ! The use of the starting handle is probably the first introduction to the workings of the motor car, that those of us born in the fifties had ! I got my practice in, on my father's Rover 14, in the " here, you have a go !" basis. Later I found that 4 cylinder motor motors were easier. In my twenties I was still at it with decrepit small lorries on building sites,and dump trucks etc. If you are not used to hand starting motors you have missed out on learning how to wheeze and cough properly, such fun...

Hey, Matt, as always, it is fantastic watching your videos and seeing what new "projects" you are working on!

Previous starter gear teeth could be the broken parts. Also the spring that you pulled out looks like what would be found on the end of a starter to retract the gear.

Hell yeah Matt, keep this stuff going , keep all that's salvageable , these analogue pieces are important, all this digital controlled crap is expensive and complicated to fix. Analogue can be fixed by anyone with tools , brains and experience

Another informative video Matt. You would make a fantastic instructor because you have a way of explaining how things work even to a mechanical novice like me. Keep up the good work.

It's pretty cool to see you do a video like this. When I first started watching your channel. You were tearing something along these lines. About a year or so. 😊

RIP Pony. Congratulations on 3/4 million subs Matt.

Love the New Intro Matt 0:02 Freaking Awesome @Diesel Creek

the intro music keeps getting better and better! and im impressed that engine ran at all, let alone for as long as it did!

That gear case is repairable actually, if it is made of cast steel it will be easier to weld than if it is made of cast iron, but even cast iron is weldable if it is heavily pre heated to a couple of hundred degree's first and then covered and allowed to cool very slowly after welding. Years and years ago when I first started in the trade it was an accepted part of the job and we refurbished many a block / gearbox casing/ and rear axle this way, that block is also repairable in the same manner, weld up the webs on the crank and have them turned back to spec by a crank grinder and do the same for any out of spec rotating surfaces and the rebuilt engine will be as good as new........important since as you said they are getting rarer than hens teeth now........there will come a day there wont be anymore left at all and you will be glad you didnt bin it. once they are gone there isnt any way back.

Old things are great, repair as long as possible and when no longer possible to repair, strip off every reusable part to keep other old things working.

Great tear down Matt! Thank you for sharing 😀

Great video. That case is probably fixable. You do so much great stuff with all this old equipment . Glad somebody takes the time to save it.

I miss the Saturday videos, became a ritual for a while. BUT, YOU do what works for YOU! You're a busy man. I'm going to watch the videos no matter WHEN you post them!!!

While we missed the "new forklift" vid, we can agree this teardown was well worth the wait! Great work, Matt.

Thanks for the video Mat, enjoyed the tear down, now you know what you have to work with.

Hey Matt, I really enjoy your videos. I bet it was a hell of a lot of fun visiting with Peg! Take care man.

Great video as always love the sound track ❤👍🏻great watch on a Easter Sunday afternoon here in the uk 🇬🇧 keep them coming, Happy Easter Matt and everyone else 🙂👍🏻🇬🇧

Yup.... Matt's getting slick with his videos, has "new stuff", doesn't show us, until way later on....😂 It's ALL good, we know how you be with the auction..... awesome as always 👍💪

i agree that you have the pieces of of a previously shattered bendix drive gear. I also thought I saw the snap ring that would retain the bendix drive on the shaft. My dad had a chevy when i was a teenager that liked to destroy it's starter in the same way.

Keep up the good work. It's a pleasure to see you, and other sites like yours, keeping the old stuff running. So much stuff today has planned obsolescence built into the design. Not too many things that you own can be repaired with a cell phone. Sometimes you just need to get your hands dirty.

DC: sees silver paste "oh, its probably ok" Every Mechanic on the Planet: nope, nope she's pretty well screwed.

Yay Sunday video, thanks Matt. Happy Easter man!

I love this version of the intro song! The old timey out of tune stuff grinds my gears.

You know the old engineer saying: "Everything was fine until it exploded." 😁😁🤘🤘

I am thinking that those extra gear teeth came from an earlier repair. They fished out the broken gear and the easy to find chunks and put it back together. Leaving the small chunks for you to find later.

morning all you DC boyz got your coffee?

Thanks for sharing Matt😊

Really glad you took the time to post this video. I'm in the process of trying to save an old Cat D7 cable dozer with a pony motor from the scrap yard. It's a long shot since it's been sitting 20+ years. Getting the pony running is going to be a challenge.

It’s a amazing how cluttered the new massive shop is now! Soon it’ll be filled like his garage at the house! Time to build another shop Matt and get that one filled up. LOL LOL

BELLEVUE HILL NSW AUSTRALIA HAPPY EASTER DC! 🐰🥚🍫

Thanks for the video Matt. Happy Easter!

I would've pressure washed the whole thing before starting. Great content! I liked the variety vs the other videos (which already have good variety.)

When you hear the intro music you know you're in a good place!!

That BYH (Big Yellow Hammer) is becoming a favorite, isn't it?

That was cool 😎 thanks for letting me watch.