Putting car in 'park' at long traffic lights...
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In auto's I do neutral all the time, even for a few seconds.
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
Sitting in drive isn't good for anything, unless you're trying to warm up the drivetrain in the cold of winter (which is when I'll leave it in gear, brake-torque a bit)
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
Sitting in drive isn't good for anything, unless you're trying to warm up the drivetrain in the cold of winter (which is when I'll leave it in gear, brake-torque a bit)
Originally Posted By: jrustles
In auto's I do neutral all the time, even for a few seconds.
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
So, you obviously have one of those new-fangled torque converters that magically disengages the input when the gear selector is put in Park...
I have bad news, folks... no matter whether the transmission is constrained by the parking pawl or the brakes, it has the same net effect.
In auto's I do neutral all the time, even for a few seconds.
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
So, you obviously have one of those new-fangled torque converters that magically disengages the input when the gear selector is put in Park...
I have bad news, folks... no matter whether the transmission is constrained by the parking pawl or the brakes, it has the same net effect.
When I got my motorcycle license they said to never take the bike out of gear at an intersection. Even though it can rest your clutch hand you never know when you may need to get out of the way, either to avoid a wreck or for emergency vehicles. The same principle applies to cars.
Originally Posted By: glock19
When I got my motorcycle license they said to never take the bike out of gear at an intersection. Even though it can rest your clutch hand you never know when you may need to get out of the way, either to avoid a wreck or for emergency vehicles. The same principle applies to cars.
Been driving for 25 years, and never had to get moving so quickly that I couldn't take a moment to put the manual transmission in gear first. Release bearings don't take kindly to having the clutch held for long periods. I had to replace the one in my MG, and even on a little car like that there are hundreds of pounds of force being applied to disengage the clutch. You'll have to pull the transmission and/or engine to replace it, not a trivial job. Even if it's not the release bearing that wears out, some cars, like my MG, have weak thrust bearings in the engine that have to endure that force against the clutch springs.
When I got my motorcycle license they said to never take the bike out of gear at an intersection. Even though it can rest your clutch hand you never know when you may need to get out of the way, either to avoid a wreck or for emergency vehicles. The same principle applies to cars.
Been driving for 25 years, and never had to get moving so quickly that I couldn't take a moment to put the manual transmission in gear first. Release bearings don't take kindly to having the clutch held for long periods. I had to replace the one in my MG, and even on a little car like that there are hundreds of pounds of force being applied to disengage the clutch. You'll have to pull the transmission and/or engine to replace it, not a trivial job. Even if it's not the release bearing that wears out, some cars, like my MG, have weak thrust bearings in the engine that have to endure that force against the clutch springs.
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Originally Posted By: leeharvey418
Originally Posted By: jrustles
In auto's I do neutral all the time, even for a few seconds.
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
So, you obviously have one of those new-fangled torque converters that magically disengages the input when the gear selector is put in Park...
I have bad news, folks... no matter whether the transmission is constrained by the parking pawl or the brakes, it has the same net effect.
Agreed, the hydraulic pump is always running, and it's pumping fluid through the cooler in the radiator, so the fluid is getting hot one way or another.
Originally Posted By: jrustles
In auto's I do neutral all the time, even for a few seconds.
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
So, you obviously have one of those new-fangled torque converters that magically disengages the input when the gear selector is put in Park...
I have bad news, folks... no matter whether the transmission is constrained by the parking pawl or the brakes, it has the same net effect.
Agreed, the hydraulic pump is always running, and it's pumping fluid through the cooler in the radiator, so the fluid is getting hot one way or another.
Originally Posted By: leeharvey418
Originally Posted By: jrustles
In auto's I do neutral all the time, even for a few seconds.
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
So, you obviously have one of those new-fangled torque converters that magically disengages the input when the gear selector is put in Park...
I have bad news, folks... no matter whether the transmission is constrained by the parking pawl or the brakes, it has the same net effect.
With the trans in park, the output side of the converter is spinning freely (trans is in neutral with the park pawl engaged to lock the output). In drive, the converter is being forced to slip more, as the output is locked at 0 rpm. It does make more heat in drive because of that.
Originally Posted By: jrustles
In auto's I do neutral all the time, even for a few seconds.
Many years ago, I started out debating heavily between neutral-drive engagement "wear" and using engine power to generate heat, to destroy the fluid and eventually settled on the former.
So, you obviously have one of those new-fangled torque converters that magically disengages the input when the gear selector is put in Park...
I have bad news, folks... no matter whether the transmission is constrained by the parking pawl or the brakes, it has the same net effect.
With the trans in park, the output side of the converter is spinning freely (trans is in neutral with the park pawl engaged to lock the output). In drive, the converter is being forced to slip more, as the output is locked at 0 rpm. It does make more heat in drive because of that.
Some people are shifting into park while others are shifting into neutral. Does this make a difference?
If a person shifts their transmission 5 extra times per day trying to reduce wear: 5 x 365 days = 1865 more shifts x 5 years = 9,125 more shifts. Is there extra component wear from these 9,125 extra shifts that negate the "savings" vs. just sitting in gear with brakes on??
If a person shifts their transmission 5 extra times per day trying to reduce wear: 5 x 365 days = 1865 more shifts x 5 years = 9,125 more shifts. Is there extra component wear from these 9,125 extra shifts that negate the "savings" vs. just sitting in gear with brakes on??
Has to be extra wear. Question is, does it matter? Normally one puts a vehicle into drive twice a day (going to work and coming home). Let's say they go up to 12 times (5 stops on each way). Six fold increase in wear. But what wears in doing this? The shift cables/rods, some solenoids in the transmission, some u-joints. What takes out a car usually? Worn clutches in the transmission, rust or accident. Or it's traded off before it's had a chance to break.
I've heard of few vehicles having worn out shift linkages, at least not since three on a tree's went away.
I have to think that, for start/stop cars, they probably are doing the same thing at every stop light. Will have to see how start/stop cars fare as the years go by.
I've heard of few vehicles having worn out shift linkages, at least not since three on a tree's went away.
I have to think that, for start/stop cars, they probably are doing the same thing at every stop light. Will have to see how start/stop cars fare as the years go by.
Originally Posted By: rslifkin
With the trans in park, the output side of the converter is spinning freely (trans is in neutral with the park pawl engaged to lock the output). In drive, the converter is being forced to slip more, as the output is locked at 0 rpm. It does make more heat in drive because of that.
Thank you. I was confused by the replies to my comment, but then came to accept that they did not know/forgot how a torque converter works.
Originally Posted By: doitmyself
Some people are shifting into park while others are shifting into neutral. Does this make a difference?
If a person shifts their transmission 5 extra times per day trying to reduce wear: 5 x 365 days = 1865 more shifts x 5 years = 9,125 more shifts. Is there extra component wear from these 9,125 extra shifts that negate the "savings" vs. just sitting in gear with brakes on??
The component wear would be roughly the same as repeated 1-2 shifts, which many fleet vehicles can make hundreds of times a day...
HEAT is what kills ATF and automatic transmissions, not shifting usually.
Also consider that a shift like 1-2 deals with a much larger RPM differential between gear ratios vs an 800rpm to 0rpm N-to-drive engagement. The 1-2 shift also takes longer, meaning more slippage on that clutchpack.
So the 1-2 clutch pack sees much more engagement each day, and it's shifts are slipped more/modulated longer than a quick (often rolling) engagement of the forward clutch.
I'm a convert; I used to be about just leaving in it gear, but eventually realised using fuel to further stress the transmission truly makes no sense.
With the trans in park, the output side of the converter is spinning freely (trans is in neutral with the park pawl engaged to lock the output). In drive, the converter is being forced to slip more, as the output is locked at 0 rpm. It does make more heat in drive because of that.
Thank you. I was confused by the replies to my comment, but then came to accept that they did not know/forgot how a torque converter works.
Originally Posted By: doitmyself
Some people are shifting into park while others are shifting into neutral. Does this make a difference?
If a person shifts their transmission 5 extra times per day trying to reduce wear: 5 x 365 days = 1865 more shifts x 5 years = 9,125 more shifts. Is there extra component wear from these 9,125 extra shifts that negate the "savings" vs. just sitting in gear with brakes on??
The component wear would be roughly the same as repeated 1-2 shifts, which many fleet vehicles can make hundreds of times a day...
HEAT is what kills ATF and automatic transmissions, not shifting usually.
Also consider that a shift like 1-2 deals with a much larger RPM differential between gear ratios vs an 800rpm to 0rpm N-to-drive engagement. The 1-2 shift also takes longer, meaning more slippage on that clutchpack.
So the 1-2 clutch pack sees much more engagement each day, and it's shifts are slipped more/modulated longer than a quick (often rolling) engagement of the forward clutch.
I'm a convert; I used to be about just leaving in it gear, but eventually realised using fuel to further stress the transmission truly makes no sense.
I wonder how many WATTS of power are consumed by mechanically shearing fluid between the torque converter's turbine and stator?
It surely has got to me more than the oil pump and alternator, perhaps as much as AC- maybe 3-600 WATTS? Just a guess.
It surely has got to me more than the oil pump and alternator, perhaps as much as AC- maybe 3-600 WATTS? Just a guess.
Why do you shout the word 'watts'?
Originally Posted By: leeharvey418
Why do you shout the word 'watts'?
To get the attention of people still operating under
'netiquete circa 1993...
Why do you shout the word 'watts'?
To get the attention of people still operating under
'netiquete circa 1993...
Originally Posted By: jrustles
Originally Posted By: rslifkin
With the trans in park, the output side of the converter is spinning freely (trans is in neutral with the park pawl engaged to lock the output). In drive, the converter is being forced to slip more, as the output is locked at 0 rpm. It does make more heat in drive because of that.
Thank you. I was confused by the replies to my comment, but then came to accept that they did not know/forgot how a torque converter works.
Originally Posted By: doitmyself
Some people are shifting into park while others are shifting into neutral. Does this make a difference?
If a person shifts their transmission 5 extra times per day trying to reduce wear: 5 x 365 days = 1865 more shifts x 5 years = 9,125 more shifts. Is there extra component wear from these 9,125 extra shifts that negate the "savings" vs. just sitting in gear with brakes on??
The component wear would be roughly the same as repeated 1-2 shifts, which many fleet vehicles can make hundreds of times a day...
HEAT is what kills ATF and automatic transmissions, not shifting usually.
Also consider that a shift like 1-2 deals with a much larger RPM differential between gear ratios vs an 800rpm to 0rpm N-to-drive engagement. The 1-2 shift also takes longer, meaning more slippage on that clutchpack.
So the 1-2 clutch pack sees much more engagement each day, and it's shifts are slipped more/modulated longer than a quick (often rolling) engagement of the forward clutch.
I'm a convert; I used to be about just leaving in it gear, but eventually realised using fuel to further stress the transmission truly makes no sense.
So just to clarify is it better (in terms of wear on the transmission) to shift into neutral or into park?
Originally Posted By: rslifkin
With the trans in park, the output side of the converter is spinning freely (trans is in neutral with the park pawl engaged to lock the output). In drive, the converter is being forced to slip more, as the output is locked at 0 rpm. It does make more heat in drive because of that.
Thank you. I was confused by the replies to my comment, but then came to accept that they did not know/forgot how a torque converter works.
Originally Posted By: doitmyself
Some people are shifting into park while others are shifting into neutral. Does this make a difference?
If a person shifts their transmission 5 extra times per day trying to reduce wear: 5 x 365 days = 1865 more shifts x 5 years = 9,125 more shifts. Is there extra component wear from these 9,125 extra shifts that negate the "savings" vs. just sitting in gear with brakes on??
The component wear would be roughly the same as repeated 1-2 shifts, which many fleet vehicles can make hundreds of times a day...
HEAT is what kills ATF and automatic transmissions, not shifting usually.
Also consider that a shift like 1-2 deals with a much larger RPM differential between gear ratios vs an 800rpm to 0rpm N-to-drive engagement. The 1-2 shift also takes longer, meaning more slippage on that clutchpack.
So the 1-2 clutch pack sees much more engagement each day, and it's shifts are slipped more/modulated longer than a quick (often rolling) engagement of the forward clutch.
I'm a convert; I used to be about just leaving in it gear, but eventually realised using fuel to further stress the transmission truly makes no sense.
So just to clarify is it better (in terms of wear on the transmission) to shift into neutral or into park?
Originally Posted By: Nate1979
So just to clarify is it better (in terms of wear on the transmission) to shift into neutral or into park?
Not much difference, except a longer gear selector lever throw, flashing reverse lights (for the guy behind you) and the engagements of 'locking pawls' when put in P.
So, neutral technically would yield the least wear.
So just to clarify is it better (in terms of wear on the transmission) to shift into neutral or into park?
Not much difference, except a longer gear selector lever throw, flashing reverse lights (for the guy behind you) and the engagements of 'locking pawls' when put in P.
So, neutral technically would yield the least wear.
Why bother, the engineers that design auto transmissions in general count on the fact that it will be left in drive while on the road, so I would keep the car in drive at all times during my time on the road. You increase the possibility for premature failure of cables, and shifter mechanisms when you toggle between drive and park or neutral.
Heat is not the killer anymore, poor fluids being unable to withstand heat are.
Our newer cars and trucks either run the trans fluid through the radiator or have a thermostat in their cooler lines or both, depending on model.
Our newest fleet vans run the trans fluid at very high temps deliberately, yet we seem to get extremely long service life from them even in very heavy duty usage...
Our newer cars and trucks either run the trans fluid through the radiator or have a thermostat in their cooler lines or both, depending on model.
Our newest fleet vans run the trans fluid at very high temps deliberately, yet we seem to get extremely long service life from them even in very heavy duty usage...
All auto trans on my vehicles here. I do put them in neutral during long lights and trains with foot on brake. Carrying on the tradition my father taught me. Not worried about bulbs, they are cheap and easy to replace.
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