DM3 Gears

[Rottentooth]

How does gearbox in DM3 work? What prevents the gears in gearbox from grinding when changing gears? Is there a clutch that disengages automatically when throttle is set to 0 (grinding in-game happens if throttle is applied)? I'm not familliar with DM locomotives, if anyone can explain how changing gears with no clutch works or have any materials that explain this, I would be very thankful. I hope the question is understandable, English is not my first language.

[pitty3878]

Reduce throttle to zero before you change gears.
There is also a diagram of the sequence just under the gear change mechanisms.
Also I suggest you play around in sandbox mode until you get used to the gear changing.

[Rottentooth]

I was afraid the question will be misunderstood. Not a gameplay question, but I don't even know what to google to get an answer. In a manual car, you press a clutch to disengage the engine from the transmission, than switch the gear and then reconnect the clutch. How does that work in DM3- like locomotives? Is the clutch automatic or what is this system called. It's not like you're jamming the shift sticks forcefully while engine is connected to the gearbox or am I wrong?

[AoFA | FightDrug *-* [GER]]

^this and i would suggest to let the gear B allways on the top when you ride light fright trains or drive empty so you dont need to change the gears so often and so fast

[Knsgf]

Instead of a dry clutch, the engine power is transferred to gearbox via variable-fill fluid coupling. The pump, which fills the said coupling, is driven by the engine, so the amount of oil inside the clutch and therefore its slip depends on engine RPM - when tachometer is close to idle, the fluid coupling is only filled partially and will readily slip, allowing a driver to switch gears safely.

[AoFA | FightDrug *-* [GER]]

Originally posted by Rottentooth:

I was afraid the question will be misunderstood. Not a gameplay question, but I don't even know what to google to get an answer. In a manual car, you press a clutch to disengage the engine from the transmission, than switch the gear and then reconnect the clutch. How does that work in DM3- like locomotives? Is the clutch automatic or what is this system called. It's not like you're jamming the shift sticks forcefully while engine is connected to the gearbox or am I wrong?

ohh that you mean no idea sry

[Rottentooth]

Originally posted by Knsgf:

Instead of a dry clutch, the engine power is transferred to gearbox via variable-fill fluid coupling. The pump, which fills the said coupling, is driven by the engine, so the amount of oil inside the clutch and therefore its slip depends on engine RPM - when tachometer is close to idle, the fluid coupling is only filled partially and will readily slip, allowing a driver to switch gears safely.

YES! thank you very much, I didn't know what it's called, fluid coupling. Here's how it works if anyone else is interested https://www.youtube.com/watch?v=11Q4g-oOLr8

[Tiretracker]

So theres a fluid coupling on the Diesel Mechanical clutch; I presume the same principle applies for the entire Diesel Hydraulic drivetrain, right?

I can only imagine the fluid pressures involved in towing 300 tons.

[Kimo]

Originally posted by Rottentooth:

How does gearbox in DM3 work? ...

If you're interested in the gearbox itself:
https://www.youtube.com/watch?v=tfT7Vrv71J0

[Kimo]

Originally posted by Tiretracker:

So theres a fluid coupling on the Diesel Mechanical clutch; I presume the same principle applies for the entire Diesel Hydraulic drivetrain, right?

Diesel-hydraulic (DH) drivetrains have no "clutch", but hydraulic motors.
Diesel-mechanical (DM) drivetrains got a fluid coupling.
There are different ways to build drivetrains.

[ling.speed]

Originally posted by Kimo:

Diesel-hydraulic (DH) drivetrains have no "clutch", but hydraulic motors.
Diesel-mechanical (DM) drivetrains got a fluid coupling.
There are different ways to build drivetrains.

A semantic quesion: how come DH drivetrain is supposed to have hydraulic motors, when it can operate operate at full power when stopped (at zero flow). Couplings can do it because they operate on slip, motros like pumps operate with fixed volumes. No flow, no power.

Maybe DH has both coupling and motor? But then motor would be redundatnt...

[pitty3878]

Originally posted by ling.speed:

Originally posted by Kimo:

Diesel-hydraulic (DH) drivetrains have no "clutch", but hydraulic motors.
Diesel-mechanical (DM) drivetrains got a fluid coupling.
There are different ways to build drivetrains.

A semantic quesion: how come DH drivetrain is supposed to have hydraulic motors, when it can operate operate at full power when stopped (at zero flow). Couplings can do it because they operate on slip, motros like pumps operate with fixed volumes. No flow, no power.

Maybe DH has both coupling and motor? But then motor would be redundatnt...

Diesel–hydraulic locomotives use one or more torque converters, in combination with fixed ratio gears. Drive shafts and gears form the final drive to convey the power from the torque converters to the wheels, and to effect reverse.

[ling.speed]

Originally posted by pitty3878:

Diesel–hydraulic locomotives use one or more torque converters, in combination with fixed ratio gears. Drive shafts and gears form the final drive to convey the power from the torque converters to the wheels, and to effect reverse.

Yeah, between DM and DH it really comes down to where the torque/speed variation is created.
For DH its at the torque converter and for DM at the gearbox, and beyond that both have gear reductions and power transfer through a work fluid.

[pitty3878]

Well I think we all learnt something.... Hope your ready for your test 😉