123 dozer conversion

[William Adams]

As I stated earlier, there's a laundry list of weird stuff to work through. I need to poke away at the engine some more. It runs really well but off-idle carburetion is still an issue. Starts pretty hard and falls on it's face going from idle to high speed. I haven't been too fixated on that because I'm running a cheesy plastic gas tank that is barely safe enough to use. I have an NOS Kohler tank in the mail somewhere between here and Indiana so I'll wait until I'm sure I have enough fuel flow before fixing the carb issue. I am also having the devil's own time getting the right generator belt. Weird pitch belt. After running and driving it a bit, it's clear that the hand control for the hydrostatic drive just won't do. Too many hands needed! To that end, I am massaging a foot control. It's working well but is a pretty crude parody of linkage. I've gotten the linkage ratios and throws worked out and have just added a "return to center" spring assembly. As it turns out, when sitting at idle without a positive centering device for the foot pedal, it likes to sort of "wander off". Not good or safe. Besides, without any spring return, the foot pedal has absolutely zero pedal feel. With boots on, it was hard to know where you were at on the pedal. The new pedal return to center linkage is pretty simple and working great. I just need to bush the pivots and clean up the "dogpatch" looks.

 

[Gage mcdaniel]

thats what i would do when that is happeing

 

[William Adams]

As a project guy, two of my favorite things are metalwork and wiring. I try to prioritize and stay mostly on task, but occasionally I'll wander off into my fun stuff. Both my son and wife voted to keep the o.e. look hood and grille, but for reasons of aesthetic and weight saving, I took the road less traveled. For one, the freaking o.e. grille must weigh 50 pounds! The height of the hood was also an issue for me. It just looked spindly and enormous.

In addition, there was a good amount of rust damage on the hood nose and wallowed out mounting points.

To that end, I built a new front grille frame from 2"x2"x16 gauge tubing. I cut the slag off the hood, then made some surgical incisions to enable me to add the rake. I welded it all back together and it's working well.

I also cut out the old, rotted dash and welded in new (from scavenged 18 gauge commercial shelves) metal. I also strengthened and welded up a number of cracks in the console at the frame mounting points. It's nice and solid.

I made a battery box to move the new auto-sized battery to the back. There's a full frame under that sheet steel. The sheet steel is also structural. Here, I'm messing around with a plow mount that my son wants. Lots of gusseting and finish work to get this stronger...

 

[PACub100]

Well, that's it...I just canceled Netflix. Why bother when I can follow this for free??

 

[kharvey]

On the carb issue check the wear in the throttle shaft if you think it's sucking air.

 

[William Adams]

On the carb issue check the wear in the throttle shaft if you think it's sucking air.

The carb is new so throttle shaft is tight. It acts like a plugged passage as adjusting the idle screw has zero effect. I suspect some manufacturing chum in a passage somewhere but the right thing to do is take it off, disassemble and be thorough with a good inspection and ream all the passages out with fine copper wire and carb spray. Also, a bit of gasket sealer on the intake and a new air cleaner. When this air filter was made, dirt hadn't been invented yet.

 

[William Adams]

A description of the subframe is in order.
I started by building the track carriers. I simply took some lengths of 2"x4" 11 gauge steel tubing and cut slots in each end just wide enough for the idler sprockets to slide into. I don't have a lot of tools so I bought a tabletop drill press from HF just to note all the holes in the carriers. I slotted the front holes so I'd have 2" of track adjustment possible. I added 4" 11 gauge flat stock under the front bearing flanges and then welded angle iron to the end of that to act as sliders for the front bearing flanges. For adjustment, I'm currently using 1/2" all-thread. We'll see if it needs springs as testing continues, but it's working quite well as is. There is enough slack in the tracks to allow them to digest whatever gets in there. I much prefer to not have sliding hardware on springs as it would be difficult to maintain bearing flange alignment if they floated. If need be, I'll add two more 5" idlers that will push up on the track immediately behind the front idler sprockets. That assembly "could" be spring loaded. Not sure how it would look, but form follows function.
Back to the frame description:
For the subframe, I wanted to be able to split the tractor top and bottom. I built a very simple subframe with "2"x4" 11 gauge steel tubing. There are two crossbars under that. One right behind the engine, another just ahead of the transmission oil filter. I made tabs to bolt the subframe to existing bolts in the tractor frame sides. To support behind the differential, I made a separate cross frame that attaches to the bottom 3 bolts where the hitch attaches to the differential.
Once all the bits were built, I slid the track carriers under the drive sprockets and aligned them to the sprockets. To get my height, I installed the chains around the sprockets and idlers and jacked the tractor up and down until I had the track tension and alignment I wanted. Then I cut the spindly legs to go from the subframe to the carriers in front and welded it all up.
It is my hope that for maintenance, I should be able to just break the tracks, remove the 7 bolts holding the subframe to the tractor and pick the tractor frame straight up off the subframe with a cherry picker. We'll find that out soon enough. There's no linkage, lines or wiring between the two halves other than the battery cables. The battery box is attached to the rear subframe so that'll need to be disconnected first.

 

[gary noblit]

William, I'm sure I speak for others also,we are enthusiastically watching your progress..Probably most of us wish we had your talent .Very impressive use of "old iron"

 

[William Adams]

William, I'm sure I speak for others also,we are enthusiastically watching your progress..Probably most of us wish we had your talent .Very impressive use of "old iron"

Thanks Gary,
I appreciate the kind words. I enjoy the sharing but also want to show folks what can be accomplished without a lot of tools. I have a wire feed welder, an angle grinder that I use for just about everything and a basic set of hand tools. I did, as I mentioned above, pick up a small drill press to drill all the holes in the track carriers, but that will come in handy for lots of other home projects. I have trolled YouTube for lots of ideas as well and wait breathlessly with popcorn for Frank's weekly bulldozer build episodes. But at the end of the day, I go my own way on things. One of my favorite mantras is from Teddy Roosevelt:
"Do what you can
With what you have
Where you are"
Very often, if we do our homework, we find that things needn't be nearly as complicated as we think they are. You'll be surprised at how many problems can be solved more easily by sitting quietly with a cup of coffee just staring at something....and thinking it through....

 

[William Adams]

A detail photo of the slotted front track carrier....

 

[William Adams]

Here, my son Will is holding a "stock" hub in his left hand and a modified one in his right. The weld in sprocket hubs are too wide to fit inside the carriers so we cut them down.

Here's my homemade lathe that we used to cut them. Will spun the drill while I cut them with an angle grinder.

Before and after. No machine work needed. It took about 15 minutes each to cut them in half.

 

[Robert Shingle]

Excellent work and ingenuity. Where there is a ”Will” there is a way. (pun intended)

 

[Cubbie]

Brilliant. Thanks for sharing.

 

[IHinIN]

Amazing work you’re doing with minimal tools

 

[William Adams]

Let's try this. It usually takes about 57 tries to post a video link...

 

[William Adams]

As you can hopefully see, I got a few issues sorted. The carb was plugged on the idle circuit. It's working much better. As to the hard starting.....well....
Note to self:
Push the "clutch/hydro" pedal in...
Starts first time every time. I guess that means I should secure, and read, an owners manual.
I can't wait to find out what else I don't know....

 

[mhomrighausen]

I LOVE IT!!!

 

[PACub100]

As you can hopefully see, I got a few issues sorted. The carb was plugged on the idle circuit. It's working much better. As to the hard starting.....well....
Note to self:
Push the "clutch/hydro" pedal in...
Starts first time every time. I guess that means I should secure, and read, an owners manual.
I can't wait to find out what else I don't know....

Reminds me of my removing the shield, cleaning out my mower deck, greasing everything, putting it all back together, putting the deck back under the tractor, hooking everything up and while gathering up my tools, wondering what the belt was laying by the rear tire. It was that Homer Simpson "Doh!" moment when I realized that I hadn't put the belt back on the deck....

 

[lelder]

William, your one of few to adress the hands needed to operate a hydrostatic cub, I agree. Somewhere on this site are photos of my foot conversion I installed on my 129 about 10 years ago, it has not been touched since and works perfectly. Good luck with a nice project especially working with your son.

 

[William Adams]

Took a light day today. I made up a test for a support roller/tensioner I've had in mind. Of course I didn't have the right fasteners. Also need to spend some time looking for just the right tensioner assembly. I'm kind of leaning toward a small coilover shock of some sort.
Retracted:

Extended:

I only made one side for now. I might make another if I'm in the mood. Otherwise I'll wait until I find some shocks.
The blue support rollers are the same diameter as the road wheels at 5". I might want to step up to a 6" for these. There will be two per tensioner, inside and outside the track chain. They ride on full width roller bearings.

On a separate note, I got done putzing and took it out of the garage so I could sweep and clean up. It started right up and runs pretty well cold now. A huge difference from the cranking and cranking. Starts now in two or three revs.
I also replaced the footpedal centering springs with the same length 3" inch but in a lighter .054 spring weight. Much nicer now. Doesn't take a couple guys to push the pedal and still goes immediately back to neutral and stays there.

As the poet said: "Bird by Bird"