OMG, you don't want much do you ..?
First up, IMO you need to know (or be told) what symptoms the machine is displaying. If someone expects you to even have a shot at diagnosing a drive train in a dozer without access to gauges or a Service Manual then they need to tell you exactly how it is behaving.
Some examples could be: -
1. No drive in all forward speeds.
2. No drive in all reverse speeds.
3. No drive in a single speed (say 1st) in both directions.
4. Converter oil overheating when pushing against a full blade.
5. Engine coolant overheating when pushing against a full blade.
1, 2, & 3 are likely transmission problems.
4 & 5 could be either converter or possibly engine.
Assuming it is a "conventional" machine with a torque divider/torque converter and powershift transmission (not hydrostatic, they're a whole different kettle of prawns) you need to know enough about the machine & its' systems to decide if a stall test is even possible without access to test gear. Some electronically-controlled machines can't be stalled at all without a laptop and going into "Test" mode.
Here's how I would stall test a converter, assuming it's a conventional tractor. Let's say it's a Cat D10R, I can give you some numbers for that. If you're really cheeky you could say you'd get into the Monitor System and be able to check the turbo boost pressure while you were testing the machine. We're assuming here that none of the conditions 1, 2, or 3 as described above are present that would point straight to a transmission problem: -
1. Start up engine, allow all systems (engine & power train at least) to warm up to operating temperature.
2. Accelerate the engine to maximum RPM on no load (trans in neutral) & note how many RPM this is. For D10R should be around 2110 +/-20.
3. Apply the service brake & release the park brake.
4. At Low Idle engage 3rd speed forward. If transmission has more than 3 speeds use top gear whatever that is. You should "feel" the transmisssion engage.
5. Accelerate the engine to the maximum RPM it will give you with the converter stalled while still holding the service brakes on. This will be less than above, probably about 400-450RPM less. Note the RPM. For D10R should be 1646 +/-20 RPM.
6. Note how fast the TC temperature gauge rises. When the High TC temp alarm goes off, select neutral and keep the engine at High Idle RPM with no load to cool the power train until the converter temp gauge comes back into the normal range.
If the tractor had good drive in 3rd speed (this means transmission clutches are not slipping) but stalled at comparatively high RPM (say 1700+) compared to High Idle I would be looking at the converter.
If the tractor had good drive in 3rd speed but stalled at comparatively low RPM (say <1600) compared to High Idle I would be looking at the engine, maybe the turbo boost boost pressure would be the first point to start.
The time taken for the TC to generate a high temp alarm can also give an indication of converter slippage.
Having said all the above I think my answer on a test paper to such a question would be something like - "If you want this machine troubleshooting correctly & completely and not just opinions then I need to have the correct tools for the job". That would be especially true if Head Office was going to use your findings to send out whatever major component might be needed to fix this tractor .........
