nortrac 3500 no steering

Are you referring to the arm on top of the case or pedal travel?

Do you have the pedals that go through the floorboards, or the pendulum style mounted on the sides of the instrument console?

Do you have the operators and parts manuals? The adjustment instructions are included.

If the machine has not operated for a long period of time and has set out in the elements there’s a very good chance the steering clutch plates are just rusted together. Sometimes they can be free’d up just by trying to exercise them while pulling or pushing the tractor. The clutch discs are not cerro-metallic as advertised, but rather a sintered bronze much like what you would find in marine and industrial transmissions.

You might get lucky.   :yes:

Yikes! Better get those stud/bolts back in with Locktite. It does sound like you will have to pull the finals.

Nice going Thomas. Are you working on a concrete floor? At this point a pic of your work would help a lot. A transmission jack can save you a lot of grief here. You can attach the sprocket flange and “slide” the final drive out as a unit once all the interferences have been removed. I’ll show a pic of my transmission jack setup tomorrow.

Separate final drive from transmission? Why? Are you getting into the bevel gear case for some reason?

This is my fault because I still use “Catspeak” sometimes (old habits are hard to break). What I call Final Drive, they call Final Transmission. What I call Bevel Gear Case, they call Central Transmission. So yes, you are correct. Sorry for that.

Thomas Andrews wrote:

Not a problem, I’m just delighted that you are staying with me and checking me. I believe that I’m heading down to the shop and try moving the “shovel bracket welding” unit (I’ve heard it called a ‘c frame’) ahead a couple inches. Any idea how much the final drive and steering clutch box might weigh? And I still haven’t quite got the swing shaft/clutch box clearance situation figured out. Will the undercarriage frame assembly move sideways?

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The “shovel bracket welding” unit/‘c frame’ is colloquially referred to as the “wishbone”. 🙂

The track “swing” frames can be moved once they are disconnected from the crossbar and equalizer bar under the engine. This will require extra blocking. Remember that the tractor frame pivots on the equalizer bar, so be careful.

The final drive/steering clutch assembly will weigh around 275 lbs.

Here is the pic of my transmission jack setup. The uprights bolt directly to the sprocket flange.

This is the big Harbor Freight transmission jack. If you go that route you will have to counterbalance it with a solid concrete block (not pictured).

I don’t remember if there is room to get a drill in there for the transmission studs, but if you can it’s an easy fix with Keenserts or Heli-Coils. Sounds like that dozer was really abused. Maybe dropped from a plane?

You bought it for a dollar? You can then spend $4k on it and still be money ahead.

There are eight bolts that hold the steering clutch case to the bevel gear case. They are accessed through the top of the bevel gear case. You will have to remove the seat and the three point hitch lift box (arms can come with it).

With that done the assembly should come loose, but machinist’s wedges may be necessary to break the gasket loose. This is where it can get tricky if the splines are worn inside the brake drum, and the clutch plate teeth are stuck in them. It might take some rotating the assembly back and forth while pulling.

I remember doing a similar job on a Cat D6 back in ’65. Another mechanic and I had to pack our tools half a mile back into the woods. I was 22. :yahoo: You couldn’t pay me enough to do it again. 😥

Great news! Circle G Tractor should have most of the parts you will need. Also, bearings and seals can be sourced locally by measurements/specimens through NAPA or your bearing house, or online.

https://www.circlegtractorparts.com/yuchai-bulldozer-parts

You need to be able to slightly rotate the transmission input shaft while applying some slight forward pressure. You don’t want to loosen the pressure plate because that might let the clutch disc fall and then you would have a problem aligning the pilot into the flywheel. You may be able to get away without pulling the engine, but if not what you will need then is a clutch aligning tool. The clutch housing can only be removed after the flywheel is removed.

A clutch alignment tool is available here:

https://affordabletractorsalesco.com/cart/sub_catalog_gallery.php?cid=3359&catid=106&picid=4538&category=Parts%20Center&sub_category=Clutch&scid=116

Every time you do something like this you learn a little trick or two that makes it go easier and quicker, and before you know it you’re good enough to open up a tractor repair shop. B-)

I thought about linear actuators but deemed they would be too slow acting in this application, so I engineered a simple cable and pulley system that has better sequencing and works very well, and has the feel of power assist. And now I can’t find the file. I’ll keep looking.

Here is the general idea. This was made up for a member that had the pendulum pedals so some of it doesn’t apply, just the blue lines. I’ll keep hunting for the mod that I did on my own dozer.

I found my file pictures if you’re interested, Thomas.

It’s a very simple setup; a length of 1/4 wire rope with an eye swaged at both ends (sorry, do not have the measurement), a 2′ Harbor Freight sheave, two 1/4″ forged shackles, one 1/4″ long shank forged eyebolt (for adjustment). I’m still hunting for the diagram, but I fear it’s lost.

Fifth pic.

NOTE:

In my considered opinion, the “fix” described here by Bob Rooks addresses THE worst feature of these 1950-era equivalent technology dozers. I’ve had my dozer for 10 years, and could not get the left brake-clutch to work, but noted that i COULD use it if I left the floorboard off, allowing the pedal twice it’s usual range.

I did not understand the silly thing at all, until I decided to sell it, and got serious about making it right for the buyer.

After I wrapped a strap around the conflicting hoses and pulled them together and up a bit, and cleaned the linkage area up, I fiddled and cursed and got nowhere.

Finally, I pulled the cotter pins, which took me damn near 2 hours, so i could FEEL the movement inside the cases. It was only then that I started to “see the light”.

BECAUSE my left brake is about SHOT, the instructions as to where the pin should be in the sequent slot before applying the pedal will not work, and the brake would NEVER get involved.

Rather, you have to feel where the brake arm begins to engage, and set things so that the front of the sequence slot is at THAT position, to effect the timing of clutch release and brake engagement in accord with the instructions.

Now this is STILL a rather delicate adjustment, and the penalty for getting it wrong may be what I May HAVE TO HAVE DONE which is pull the track, bull wheel, saddlebags, and other stuff I’ve no interest whatso-fn-ever in doing:
just to replace a brake band. (I had read that you didn’t have to do that to replace a brake band, but Mr. Rooks disabused me of that hope: and I do regret to note he ain’t been wrong yet,afaik!)

So, what Bob has show above is a way to “isolate” the brake function from the hazards of incorrect adjustment, by giving the brake actuation stroke twice the distance it would normally have to effect engagement.

So kudos, :good: :good: plaudits, encomiums, and HuZZAS to Mr. Bob ROOKS! :yahoo:

I might add that my cable and pulley system not only addresses the shortcomings of the original linkage system, it also requires much less effort to apply the brakes. The pulley is anchored in the original  “Power steering”, if you will. Here the system is used on pendulum pedal equipped dozers.