Today I gave the D2 5U an oil change; and then had my first opportunity to go out and play around, pushing some brush and stuff.  Although I’m a pretty fair operator on my excavator and rubber tired tractor/loader, this is my first real experience on a dozer.  So I’ve got a lot of learning to do, but the controls are pretty intuitive and it’s a blast!  My place is kind of steep with little draws and ridges, and lots of brush & trees, so it adds to the challenge.  I knew it was going to be a bouncy experience, tricky to manage the blade, but I’m actually surprised at how comfy the factory seat is!  I’m lucky it appears to be re-upholstered.
One thing that surprises me is that for a 5 speed, it’s not lower geared.  I mean for a CRAWLER this thing doesn’t exactly crawl in first gear!  I found myself feathering the main clutch, and I’ll bet that’s a bad habit to get into?
It came with a homemade brush rake made from RR rail, and it works pretty good.  I’m really quite impressed with the machine, it will really push pretty damn good!  It’s really everything I was hoping it would be.
Wondering about putting the larger front idler’s in it…. Is that an “easy” swap?  And if so are the idler’s hard to find?  Is it worth it?
It looks like my track pins are pretty worn.  My tension adjustment is all the way extended.  I’m guessing that’s gonna be a pretty big job?
Anyways, I’m stoked to have entered the dozer world!  Thanks everyone for your advice and inspiration!

Bigger idler would require extra track links. There are a few 5 roller machines out there; It might help a lot to have some counterweights at the rear as well.
A tidbit: D2 running gear hard to source new; some of us use retired John Deere rice Harvester tracks. They are actually Caterpillar links, pads, rollers and idlers.
Hence, sometimes you will see a D2 with off color yellow UC (JD yellow!).
Any chance you have optional tall gears on yours? I have a 4U SPG that is much faster than stock transmission. Mainly used in grape vineyards.
Glad you got to play! JM

I think there have been posts on this forum in the past about D 3 chains fitting on D 2’s without huge modifications. Others will either confirm or deny whether this can be achieved. It is great fun driving these little machines around.

Set the governor control (throttle) open just enough to do the work at hand. Let her lug some. I'm sure you're not trying to set any production records especially if your just trying to enjoy your new machine.

I would agree with Potato on the D2 speed ranges. We just use ours around the farm for small grading jobs, cutting paths through the woods, etc. on hilly terrain. For this type of work, 1st is too fast. I can't imagine who would ever use 4th or 5th gear - the tracks would fly off! I wish Cat had shifted all the gears ranges lower, so 1st was ultra low and most work would be done in 2-3. I am a rank amateur operator as well, so I am sure the professionals on a job would be using the higher gears. The D2 sure is fun to use for these little jobs though, even if with my skills, the "grading" tends to look like a washboard when I'm through with it!

Multi use general purpose machines are never the best at anything. The D2 was a multi purpose machine that you can use lots of places and jobs. We have a member that has D2 pulling a grain drill, and shared pictures. I would guess he is using the higher gears. Then in " Show us your D2's " thread on page 8 we have 6 in a vineyard. I would guess those use the higher gears as well. Looking over the pictures in the show your D2's it looks like more without a blade than have one.

Many old timers as dozer operators have told me the smaller the tractor the harder it is to make a nice smooth pass. They also talked of the further ahead of the tractor the blade is the harder not make "speed bumps". Also longer tracks helps keep them from pitching and bucking.

My very limited experience says the dirt can make you look the expert or a fool. With California's very mixed geology there are all kinds of mixes within feet of each other. I can be cleaning grass off roads thinking I know what I am doing. All smooth and nice behind me. To making the biggest mess of speed bumps possible. One pasture I rent the owners has guy with road grader scrap the roads. In adobe dirt that gets big cracks it will pull large clods up and make nasty speed bumps too.

Thanks everyone for the great feedback. Just think how cool it would be if someone offered rubber replacement tracks for these old machines!

The main reason I picked up this machine is that I’m into old tractors, and have been kind of yearning for a crawler for a while. I wasn’t seeking one out though, and just kind of lucked into this and got a good deal on it. But it’s low hours (4700), runs good, and I might as well make good use of it right? I plan to use it to clear some brush, build some more tractor trails, and do some forest cleanup.
I like the idea of adding counterweight at the rear, I hadn’t thought of that and it makes a lot of sense. Otherwise, I probably ought to just leave it as is, take good care of it, and try to make good use of it without breaking it or investing a lot into it.
On the other hand…. I’m vulnerable to ideas.

Hi, Potato Wilson.
The D2 was basically designed as an agricultural tractor with gearing set up for that sort of work, which is usually done at somewhat higher speeds than dozer work.

Glad that you enjoyed your experience.

Yes, larger front idlers would help quite a bit but, as mentioned above, you do need to add an extra link per side to accommodate the extra circumference of the large idler.

Just my 0.02.

 Add on surplus rubber pads are out there. Member John Souza still makes them to order I believe.
Nice to have. I’ve got a couple sets on machines here.
I used to use my D2 with rubber pads to do quite a bit of retrieval for implements that I would purchase.
A couple of machines I’ve come across with full rubber tracks, but not impressed. Heard it outweighed the value of the machine too. JM