NEVER do THIS to your Automatic Transmission Car | The Car Care Nut

[Dr.Kamiya]

tl;dw:

A Toyota Master Diagnostic Technician shares 7 Things you should never do to an automatic transmission.

Folks save your expensive transmission. Never do this to your automatic transmission!

In this video I will go over 7 things you should. never do to an automatic transmission.

First Protect the parking pawl! The parking pawl is a small metal part inside the transmission that locks it when you're in park. Slamming your car into park before coming to a complete stop or letting the weight of the car rest on it is a sure way of risking damage to the parking pawl.

Third Warm up your transmission before take off. Wait WHAT? Most people warm up their engine but in reality modern engines don't need much warming up. It's your transmission that needs a little bit of warm up to get going well.

Fourth Don't use your transmission as a brake! Downshifting intentionally to slow down the car puts extra load on the transmission. Most people do this to save their brakes which cost a fraction of what the transmission costs.

Fifth In snow driving if you get stuck, Don't just rev up the engine and let the wheels spin. This puts a tremendous load on your transmission.

Sixth Protect your Shifter! Accidents happen where we spill things over the shifter, But don't just leave it be. Clean the shifter and dry it up inside to prevent further issues.

Last but not least Don't put your car in neutral in short stops like traffic lights.

Watchu guys think?
There's a few items here that it turns out I'm not careful enough about, like putting it in park too quickly when in a hurry, or putting it in neutral during short stops (didn't know this causes engagement/disengagement of the clutch that causes wear).

[Dr.Kamiya]

*Mods: Sorry if I posted this in the wrong section. Just realized The Workshop / Transmission Talk will be a better fit.

[Motortrend]

tl;dw:



Watchu guys think?
There's a few items here that it turns out I'm not careful enough about, like putting it in park too quickly when in a hurry, or putting it in neutral during short stops (didn't know this causes engagement/disengagement of the clutch that causes wear).

Some stoplights here take 90 seconds to turn green. I usually put it to neutral and put on the hand brake while waiting. I'm not going to leave it in D and step on the brake for that long.

[dr. d]

Some stoplights here take 90 seconds to turn green. I usually put it to neutral and put on the hand brake while waiting. I'm not going to leave it in D and step on the brake for that long.

in my opinion, keeping the AT on D, and stepping on the brakes, while waiting for the red to turn green, is potentially dangerous.
"isang langaw lang yan sa loob nang kotse, can make the driver lose concentration and release the brake pedal..."

an online mechanic's program in youtube recommends D + footbrake, however...

[oj88]

1. Parking pawl - I generally agree... but these are not exactly as fragile as people think they are. However, it will break if it's frequently abused
2. Replace the ATF - I totally agree. Lifetime fluids are a myth to anyone who likes to keep their cars trouble-free
3. Warming up the A/T - Not really applicable in our tropical weather. But don't thrash it either
4. Engine braking - As he says, do it conservatively to regulate speed and prevent brake fade on long downhill roads. It's a safety issue not to overheat the brakes. However, don't do it to slow down the vehicle every time you need to stop. Though, most modern A/Ts would apply light engine braking when you step on or just lightly tap on the brakes. Helps with fuel economy
5. Driving in snow - Again, not applicable to us. The closest equivalent scenario would be doing donuts or getting unstuck on sand. Don't force it or risk overheating the A/T
6. Protect the shifter from spills, physical abuse, etc. - This is self-explanatory...
7. Unnecessary shifting between Drive and Neutral - Again, moderation is key. It's ok to shift to Neutral (+ handbrake) when in a particularly long stop. But don't do it every time you come to a stop

[Motortrend]

in my opinion, keeping the AT on D, and stepping on the brakes, while waiting for the red to turn green, is potentially dangerous.
"isang langaw lang yan sa loob nang kotse, can make the driver lose concentration and release the brake pedal..."

an online mechanic's program in youtube recommends D + footbrake, however...

Yes, that too.

[baludoy]

coincidentally, i also watched this vid earlier today.

i guess the algorithms of every tsikoteer sort of mirrors each other.

[carxynogen]

in my opinion, keeping the AT on D, and stepping on the brakes, while waiting for the red to turn green, is potentially dangerous.
"isang langaw lang yan sa loob nang kotse, can make the driver lose concentration and release the brake pedal..."

an online mechanic's program in youtube recommends D + footbrake, however...

That's the purpose of auto-hold feature in some vehicles na naka EPB.
I am always using the auto-hold feature.
If sa traditional hand-brake naman, no choice but to switch to P (switch to N+handbrake before going to P) if mataas pa time ng stop signal for safety reason.

If sa N daw kase, umiikot pa yung gear ng transmission mo na naka freewheel rotation.
Kaya daw not recommended to switch to N if long stop.
Mas better pa raw naka D dahil naka lock yung gear so hindi siya moving as long as nakatapak sa brake/EPB.

[Walter]

Use P only when parking ... not a smart idea to use when at a stop light ... there's a reason it's labeled as P = Park ...

[oj88]

If sa N daw kase, umiikot pa yung gear ng transmission mo na naka freewheel rotation.
Kaya daw not recommended to switch to N if long stop.
Mas better pa raw naka D dahil naka lock yung gear so hindi siya moving as long as nakatapak sa brake/EPB.

Wrong. Neutral is where the A/T is most "relaxed". Everything is free-wheeling, including the torque converter.

When in Drive and with the brakes applied and/or auto-hold activated, the torque converter is engaged, adding load to the system. Specifically, the impeller (engine side) is constantly trying to transfer power by pumping ATF to the turbine (transmission side), which is held stationary due to the brakes being applied. This constant churning of the ATF (stuck between a hard place and a rock) can raise the ATF temp somewhat. And because there's that viscous interface in the torque converter adding load to the engine, it increases fuel consumption.

Notice how the idle sags ever so slightly when you shift from Neutral to Drive? The torque converter is engaging and trying to move the car, but the brakes (or auto-hold) is preventing that from happening. This is like half-engaging the clutch while in 1st gear on an M/T with the brakes applied.

So, feel free to shift to Neutral during long stops. You're doing your A/T, engine, and yourself a favor.

[Walter]

Also thought this was the case before ... but they did a test and fuel consumption is the same when in Neutral or Drive at a stop light ... when you search online, most will advise leaving it in Drive and not shift to Neutral ... trying to understand why this is the case ... just doesn't make sense ... might have something to do with auto brake hold being more available nowadays ... for practical and safety reasons, still shifting to Neutral at a stop light for safety ...

Maybe it's also due to the new generation drivers shifting to Neutral every time the vehicle stops ...

[Motortrend]

Wrong. Neutral is where the A/T is most "relaxed". Everything is free-wheeling, including the torque converter.

When in Drive and with the brakes applied and/or auto-hold activated, the torque converter is engaged, adding load to the system. Specifically, the impeller (engine side) is constantly trying to transfer power by pumping ATF to the turbine (transmission side), which is held stationary due to the brakes being applied. This constant churning of the ATF (stuck between a hard place and a rock) can raise the ATF temp somewhat. And because there's that viscous interface in the torque converter adding load to the engine, it increases fuel consumption.

Notice how the idle sags ever so slightly when you shift from Neutral to Drive? The torque converter is engaging and trying to move the car, but the brakes (or auto-hold) is preventing that from happening. This is like half-engaging the clutch while in 1st gear on an M/T with the brakes applied.

So, feel free to shift to Neutral during long stops. You're doing your A/T, engine, and yourself a favor.

This makes sense.

[Verbl Kint]

Use P only when parking ... not a smart idea to use when at a stop light ... there's a reason it's labeled as P = Park ...

I wonder how much force a parking pawl can take when you get bumped from behind at a traffic light.

[oj88]

Also thought this was the case before ... but they did a test and fuel consumption is the same when in Neutral or Drive at a stop light ...

Oh, but they do. Though not that significant, but they do add up.

I've done this experiment on two vehicles.... my old Civic 1.8 and my Innova 2.8 Diesel.

Civic 1.8 idle fuel consumption (Liters per Hour or LPH) when in Neutral vs Drive and with the A/C compressor engaged and disengaged:


Innova 2.8 Diesel idle fuel consumption when in Neutral vs Drive:
Neutral: 0.7 LPH

Drive: 1.0 LPH


So in both cars, gasoline and Diesel, the added fuel consumption is roughly 30% when you leave it on Drive when idling.

when you search online, most will advise leaving it in Drive and not shift to Neutral ... trying to understand why this is the case ... just doesn't make sense ... might have something to do with auto brake hold being more available nowadays ... for practical and safety reasons, still shifting to Neutral at a stop light for safety ...

Maybe it's also due to the new generation drivers shifting to Neutral every time the vehicle stops ...

The choice to shift to Neutral at a stop depends on the circumstances. Short stops, leave it on Drive. Long stops, put it in Neutral. Whether your stop is to be considered Short vs Long is subjective, but personally, I consider 90 seconds or longer to be "long enough" to warrant a shift to Neutral. It's not a hard rule because, again, it depends on the actual circumstances.

[carxynogen]

Use P only when parking ... not a smart idea to use when at a stop light ... there's a reason it's labeled as P = Park ...

That's why I shift to N first and engage handbrake before going to Park.
So that all the loads are not in the P but on the handbrake.
2-3 mins sa stoplight, medyo ngalay na tapak brake.

I am still contemplating to shift to N, after oj88's explanation make sense.

[dr. d]

as someones already explained,
idle at D, with the brakes engaged, and the engine crankshaft rotates against a resistance. the brakes are also stressed.
idle in N, and the crankshaft rotates against a significantly lower resistance, and the breaks are not stressed so much.

[Walter]

The choice to shift to Neutral at a stop depends on the circumstances. Short stops, leave it on Drive. Long stops, put it in Neutral. Whether your stop is to be considered Short vs Long is subjective, but personally, I consider 90 seconds or longer to be "long enough" to warrant a shift to Neutral. It's not a hard rule because, again, it depends on the actual circumstances.

This summarizes it well ... to add to this ... if you see the stop light just turn from green to red, then shift to Neutral ... when there is already a long line waiting at a stop light, leave it in Drive since chances are that the light is about to turn green ... unless there's a gridlock ...

From Drive, foot brake then Neutral then parking (hand) brake then release foot brake ... but do not shift to Park ...

[ice15]

just sharing...

ako din, I will always put the vehicle in neutral (then handbrake) kapag matagal akong maghihintay.

pero with our Zenix...

naka-pila ako to enter the parking (it was full) kaya I decided to put it in "N" tapos handbrake ako... when the engine was about to start, nag notify yung car to put the car in D... personally, di ko maintindihan why that happened... never experienced that before kapag nasa P yung shifter ko

[Motortrend]

Oh, but they do. Though not that significant, but they do add up.

I've done this experiment on two vehicles.... my old Civic 1.8 and my Innova 2.8 Diesel.

So in both cars, gasoline and Diesel, the added fuel consumption is roughly 30% when you leave it on Drive when idling.



The choice to shift to Neutral at a stop depends on the circumstances. Short stops, leave it on Drive. Long stops, put it in Neutral. Whether your stop is to be considered Short vs Long is subjective, but personally, I consider 90 seconds or longer to be "long enough" to warrant a shift to Neutral. It's not a hard rule because, again, it depends on the actual circumstances.

30% is a significant difference. And yes, it adds up.

[labayds]

just sharing...

ako din, I will always put the vehicle in neutral (then handbrake) kapag matagal akong maghihintay.

pero with our Zenix...

naka-pila ako to enter the parking (it was full) kaya I decided to put it in "N" tapos handbrake ako... when the engine was about to start, nag notify yung car to put the car in D... personally, di ko maintindihan why that happened... never experienced that before kapag nasa P yung shifter ko

Hybrid? If so, the hybrid battery cannot charge if the shifter is in N. It has to be in D or P for it to be able to charge.