EcoModder.com

EcoModder.com (https://ecomodder.com/forum/)
-   Hypermiling / EcoDriver's Ed (https://ecomodder.com/forum/hypermiling-ecodrivers-ed.html)
-   -   Can driving in neutral damage transmission? (https://ecomodder.com/forum/showthread.php/can-driving-neutral-damage-transmission-22657.html)

Atheria 07-20-2012 12:42 PM

Can driving in neutral damage transmission?
 
Hello everyone. I have an automatic 2008 Scion xD named Bob that I love very much. I've been "hypermiling" with him for months now, getting his rated 26 city/32 hwy up to a combined average of 35-36 mpg. Besides driving slower (which kills me...but I'm doing it) one of the main things I do is throw the car into neutral as much as possible. I was just talking to a mechanic at Toyota/Scion and he was a little concerned that what I'm doing might wear out my neutral gear sooner than it should. Is that possible? I do not want to do anything that might harm Bob's transmission.

Thank you,
Atheria

Fat Charlie 07-20-2012 01:03 PM

Check and see what the owner's manual says about towing it. If it wants you to be on a flatbed, stop doing it.

ksa8907 07-20-2012 01:19 PM

im not an expert, but as long as the engine is running, there should be no problems as the pump is still lubricating the gears.

you may have to do some digging, but after searching for my car i discovered that it has a different shift schedule for neutral depending on speed. like, above 8mph it idles at 1000-1200rpm and won't actuate certain solenoids until the speed is below 8mph.

Atheria 07-20-2012 01:26 PM

Towing
 
UH OH. It says it should not be towed with all 4 wheels on the ground. I pray I have not damaged anything! I've been doing what I've been doing for months! Thank you for the information. Now I'm wondering if I should pay the $150 fee to have Toyota take a look at my transmission while it's still under warranty for a few weeks "just in case".

Atheria

rmay635703 07-20-2012 01:30 PM

My Dodge in Neutral idles between 500-600rpms in Drive it Idles 1000-1200rpms.

My Dodge really isn't supposed to be "flat towed" but I coast in neutral all the time and even with the engine off, no issues. (Deep in the manual even though dodge strongly discourages flat tow it does admit up to 25mph for 10miles)

But then again my low mileage clean and perfect Dodge is worth the salvage value only so I don't care if I destroy the thing since I can't sell it.

That said, YES your transmission may wear slightly faster (make more heat) if your idle speed changes in neutral versus in gear because the pump is pumping more slowly.

Thing is, this is over such a short distance and the temperature gain is so small unless Toyo purposely did something nefarious I can see no way that it will lead to a statistically significant increase in failure rate.

Cheers
Ryan

Atheria 07-20-2012 01:30 PM

Solenoids?
 
Quote:

Originally Posted by ksa8907 (Post 317880)
im not an expert, but as long as the engine is running, there should be no problems as the pump is still lubricating the gears.

you may have to do some digging, but after searching for my car i discovered that it has a different shift schedule for neutral depending on speed. like, above 8mph it idles at 1000-1200rpm and won't actuate certain solenoids until the speed is below 8mph.

I don't even know what a solenoid is. :-) I was reading the 109 tips just now and do see that it's BAD to turn a car off and coast if it's an automatic transmission, but my engine is indeed on when I coast in neutral. That might be my saving grace. All I need is to get an extra 5 mpg by trashing my transmission...ugh.

Thank you,
Atheria

Atheria 07-20-2012 01:35 PM

Ummm.....I coast A LOT.
 
Quote:

Originally Posted by rmay635703 (Post 317887)
My Dodge in Neutral idles between 500-600rpms in Drive it Idles 1000-1200rpms.

My Dodge really isn't supposed to be "flat towed" but I coast in neutral all the time and even with the engine off, no issues. (Deep in the manual even though dodge strongly discourages flat tow it does admit up to 25mph for 10miles)

But then again my low mileage clean and perfect Dodge is worth the salvage value only so I don't care if I destroy the thing since I can't sell it.

That said, YES your transmission may wear slightly faster (make more heat) if your idle speed changes in neutral versus in gear because the pump is pumping more slowly.

Thing is, this is over such a short distance and the temperature gain is so small unless Toyo purposely did something nefarious I can see no way that it will lead to a statistically significant increase in failure rate.

Cheers
Ryan

Hi Ryan,

When I pressed the mechanic and said, "Well, if I'm using neutral more, aren't I also SAVING the other gears by not using them as much?" And he said that was true. He didn't seem OVERLY concerned about what I've been doing and said the transmission should last 150-200,000 miles, but I am a bit "nervousy" and don't want to jeopardize anything. The thing is, I coast a lot. I sometimes coast at 65 mph on the freeway. I don't just coast to stop signs. I can go a mile at a time in neutral if the street is slightly downhill. You did make me feel a little better though.

Thank you,
Atheria

Fat Charlie 07-20-2012 01:51 PM

I wouldn't bother, or even worry. Toyota's a fine manufacturer and you've only been doing this for a short time. Worst case, maybe there's a little more wear on some of the innards than there otherwise would be. Maybe someday you'll need an overhaul somewhat sooner than otherwise.

Note- I'm not a tech, or an expert on what exactly gets damaged by running in neutral.

Phantom 07-20-2012 03:31 PM

Neutral gear? If it is in neutral it is not in gear. You will be fine as long as the car if running when rolling in neutral as the engine keeps trans fluid pumping. If the car is off trans fluid does not flow and then parts get hot and issues can start. RVs will flat tow cars that do not allow it by adding a transmission fluid pump to keep the parts that are moving with the wheels lubed.

Ford Man 07-20-2012 04:18 PM

As others have already stated, I don't think it will damage the transmission as long as the engine is running and pumping fluid.

Frank Lee 07-20-2012 04:42 PM

"Wear out the neutral gears"? I'd be inclined to not trust that mechanic anymore.

night9 07-20-2012 05:16 PM

I think the real concern is not the coasting in neutral (as long as the car is running) but actually putting the car back in gear from nuetral at speed repeatedly that may wear components on the transmision faster. Any thoughts on that?

Frank Lee 07-20-2012 05:21 PM

If it's a gentle re-engagement I'd say it's fine and if there's a clunk, grind, or lurch I'd say it's not.

Atheria 07-20-2012 06:00 PM

To clunk or not to clunk...that is the question.
 
Quote:

Originally Posted by Frank Lee (Post 317916)
If it's a gentle re-engagement I'd say it's fine and if there's a clunk, grind, or lurch I'd say it's not.

Thank you EVERYONE for responding. Since my tranny only has a warranty on it for less than a month, I'm panicking. Brake Masters said there was some metal in my transmission fluid, which IS concerning IF true. I did eventually have them change the fluid during my recent oil change.

Regarding putting the car back into drive after coasting in neutral at 40 mph or whatever, USUALLY I am good at it and know how to "feel" so that I go smoothly back into gear with no clunking. I will admit I clunked it a few times when I was getting used to switching back and forth. But the vast majority of the time I do it perfectly. I noticed the transmission can clunk even if I stay in drive, for example, if I have been coming down a hill to an intersection and have to slow way down to turn and then speed up again. If I hit the gas too hard, sometimes it'll clunk. Gentle is the name of the game...which, of course, also helps gas mileage, which is my goal.

:-)
Atheria

Frank Lee 07-20-2012 06:18 PM

SOME metal- depending on what and how much there is- is normal and not automatically a cause for alarm.

user removed 07-20-2012 06:53 PM

In most conventional automatic transmissions the primary pump is driven off of the torque converter. As long as the engine is running you have pressure for lubrication and to activate the bands which clamp down on planetary gear sets for power to the wheels.
Never coast engine off in any conventional AT because you have stopped all lubrication.

I would not even risk it if the owners manual said flat towing was OK. Cars have data recorders that show what you were doing and that would allow the manufacturer a way to deny any warranty claim.

I coast my 2011 Fiesta in neutral regularly, but it is a salvage rebuilt vehicle with no manufacturer's warranty. I have reengaged drive as high as 75 MPH without issues. The transmission control unit apparently detects vehicle speed and picks the appropriate gear when I re-engage drive. It usually goes to 6th (highest) gear then to a lower gear if my speed is below 40 MPH.

My powershift 6 speed is an automated manual transmission, completely different from your Toyota. I have coasted in neutral in my 06 Corolla without issues. I think you should be fine, but then take any advice at it's value, which in my case is.

"I ain't paying for your broken transmission!"

regards
Mech

mcrews 07-20-2012 07:58 PM

I had a totota avalon that I engine on coasted in neutral....alot. never had a problem sold the car at 216,000 miles

GRU 07-20-2012 10:39 PM

The owners manual will say the car should not be towed with all wheels on the ground because the engine is not running if you do that

Atheria 07-20-2012 10:43 PM

You've all made me feel better, thank you. Now I am "nervous" though and don't know if I should go back to driving like a "normal person" full-time or what. I drove in gear all day and hated it. I miss my coasting in neutral! In gear, it seemed like the car was always being held back when on a hill. Pfffffffffft.

:-)
Atheria

UltArc 07-21-2012 12:35 AM

I am by no way a professional at all, but I have a little experience that may help.

My 89 S10 Blazer, in 2007, had its tranny taken apart by my mechanic, a Jehovas witness. He aaid there were metal shavings, and he wiped them out, and it was fine. From his account, a series of gears constantly rotating is supposed to do that. That sounds like brake masters wants to break your wallet.

In most newer vehicles, no throttle in gear is better han coasting in neutral. I do not know this for FACT in ALL situations, but It was explained to me that the computers now know how to coast in gear, and when we people think we know better and put it in neutral, the tranny and engine are thinking 'oh crap, what's going on' and use more fuel to be ale to adjust faster.

Example: if you are on the highway, 55 mph. In gear, you can coast and use little fuel not accelerating. If you are in neutral, the tranny may be expecting you to suddenly drop to 2nd, 1st, whatever.

But I'm sure it varies. Just DON'T go off of rpm to judge. When I shift into 1st to go down a steep hill at 35, I approach 5000 rpms. But my mpg are not the 3-7 mpg I get when I am at 5000 rpm getting on the highway in first gear lol, rather 45+

my point is, every car is different, and you can only believe half of what you see, and nothing that you hear. I hope you find your answer and some peace :)

ksa8907 07-21-2012 01:04 AM

For shifting back to drive while at speed, just give it some gas to match the rpms to whatever speed it should be turning when in gear, like a manual.

Metal powder from the gears is normal, shavings and excessive clutch material is not.

Xist 07-21-2012 01:10 AM

How much does your transmission needs to be lubricated when you are in neutral?

Atheria 07-21-2012 10:45 AM

But I'm RPM obsessed. :-) They drop down SO much when I'm in neutral I have to be getting better mileage. Well, actually, the car's built-in "avg. mpg" sensor clearly shows my mpg increases when I'm in neutral. And then there is the whole issue of "gear resistance" where the car just doesn't roll as easily or as far when in gear as opposed to neutral. Oh the dilemma!

I do have a feeling that Brake Masters was exaggerating the metal in the transmission fluid thing. They showed it to me quickly but I don't recall major chunks of anything.

Atheria

user removed 07-21-2012 02:36 PM

A 2.5 liter 4 cylinder engine uses about .25 gallon of fuel idling. My 02 Insight (1 liter 3 cyl) used .11 GPH idling. Your Toyota probably uses between .15 and .20 GPH while coasting in neutral with the engine running as long as you do not have the AC on.

If you are coasting at 60 MPH and using .2 GPH then your mileage in that instant is 60/.2 or 300 MPG. That will bring your average back up very quickly.

regards
Mech

Atheria 07-21-2012 02:53 PM

MPG sensor
 
Quote:

Originally Posted by Old Mechanic (Post 318022)
A 2.5 liter 4 cylinder engine uses about .25 gallon of fuel idling. My 02 Insight (1 liter 3 cyl) used .11 GPH idling. Your Toyota probably uses between .15 and .20 GPH while coasting in neutral with the engine running as long as you do not have the AC on.

If you are coasting at 60 MPH and using .2 GPH then your mileage in that instant is 60/.2 or 300 MPG. That will bring your average back up very quickly.

regards
Mech

I usually keep my sensor set at "avg. mpg" and not "mpg" but when I've peaked while coasting or driving super efficiently I've seen it read 99.9 but I think that's as high as it can handle. :-)

Atheria

Cd 07-21-2012 03:03 PM

Any advice on keeping a transmission alive that already has internal damage ?
I removed my metal bellypan that was flush with the transmission, as well as the grille block.
I notice my transmission seems to shift ok till it heats up after around 10 minutes of driving at freeway speeds.
Would a more heavy duty transmission cooler keep my transmission alive for a while ?

mcrews 07-21-2012 09:47 PM

Quote:

Originally Posted by ksa8907 (Post 317976)
For shifting back to drive while at speed, just give it some gas to match the rpms to whatever speed it should be turning when in gear, like a manual.

Metal powder from the gears is normal, shavings and excessive clutch material is not.

I have to question this advise.
I have owned may different cars (automatics) and have NEVER rev'ed up when going back in gear.
The tourgue converter then has to compensate and that is BAD.

ksa8907 07-21-2012 10:31 PM

I suppose it would depend on the transmission, but I know mine will jerk above 40mph if I don't rev the engine to about 1500rpm. Im not suggesting holding the pedal down, just give it a tap and shift to drive. Do whatever you want, this is what works for me.

Xist 07-22-2012 02:22 AM

Minutes after buying my first car someone pulled in front of me, I hit my brakes, and they squealed, so I went to Brake Masters, that advertised $99.88 for four wheels, in most cases. They came back and said that the brakes would be that price, but that I needed to replace all of these other things, and the total would be around $450. While I waited they told countless other customers exactly the same thing, so I had a bad experience with that chain.

Do you do all of your business there?

Fat Charlie 07-23-2012 09:16 AM

Those chains make their money on the upsells. It's not unethical, it's just using advertising well. They know that by the time your car is old enough that pads and rotors all around for $100 is something you're in the market for, they're not going to be able to touch it without half of the underbody disintegrating- your shiny new pads and rotors aren't going anywhere with that brake line pouring fluid on the floor. It's on the lift and you can either pay for the upsell or pay them to put it back together in nearly undriveable condition.

I've seen ads for cheap mufflers with lifetime warrantees. Nothing else is cheap ot warranteed for life, and everything else is going to need replacing with it. It's easy to give away a muffler or pad set at cost if it brings in someone who needs a lot of work done.

UltArc 07-23-2012 10:02 AM

Quote:

Originally Posted by mcrews (Post 318055)
I have to question this advise.
I have owned may different cars (automatics) and have NEVER rev'ed up when going back in gear.
The tourgue converter then has to compensate and that is BAD.

I had a 97 Ford Escort, and it did need extra throttle before going in gear or it would lurch more. I remebered it happening, and was thinking what car was it, yea, it has happened with an automatic with me. I mean, that was at highway speeds, 65+, but I think that what you guys were talking about.

Mustang Dave 07-23-2012 08:56 PM

Since you're a psychic medium, YOU should be able to tell US what kind of damage you could do to your transmission by coasting in neutral. I (for one) am completely unconvinced concerning your psychic ability. Why haven't you won the lottery every time?;)

Xist 07-23-2012 11:39 PM

I have never lost the lottery. Who is the psychic?

rmay635703 07-24-2012 02:13 PM

Quote:

Originally Posted by Xist (Post 318356)
I have never lost the lottery. Who is the psychic?

I had never lost the lottery either until I played for the first time last week, I guess I was psychic all these years, never again.

Mustang Dave 07-24-2012 09:26 PM

Quote:

Originally Posted by Xist (Post 318356)
I have never lost the lottery. Who is the psychic?

Look at the OP's profile. I'll crawl back under my rock, now. :)

jtlemon 07-24-2012 11:06 PM

The transmission will be fine
 
I am not an expert on toyota's however I am an ASE certified master technician and a GM master technician and here is my two cents:
1- Automatic transmissions do not have a "neutral gear" when they are in neutral none of the clutches are applied and everything is basically freewheeling. what wears in an automatic transmissions is the clutches, and they only wear if they are slipping (ie low hydraulic apply pressure), or during the brief moment they slip as they they are applied, until they are fully applied and the assembly is now rotating at the same speed. the only wear you are doing to the transmission is the additional shifting, which is nothing to be too concerned about.
2- the manufacturer will not deny a warranty claim because you have been shifting into neutral. i have seen GM warranty transmissions that were physically broken in half from abuse. the vehicle data recorders that are on the vehicles give us a snapshot of up to 2 min of data when a dtc occurs, and it is a pretty limited amount of data we have.
3- as long as the engine is running, the transmission pump is providing lubrication. chrysler in particular does not run the pump in park, but all transmissions run the pump in neutral and will be lubricated.

In short, i wouldn't be afraid of damaging a transmission by putting it in neutral, no matter how new or old the car is. modern automatic transmissions are extremely robust and can handle a surprising amount of abuse. To put your mind at ease, I work primarily on oil field trucks that spend most of their time off-road and see more abuse than people can imagine, and it is surprising how few failures we see.

Atheria 08-08-2012 11:35 AM

Brake Masters
 
Quote:

Originally Posted by Xist (Post 318073)
Minutes after buying my first car someone pulled in front of me, I hit my brakes, and they squealed, so I went to Brake Masters, that advertised $99.88 for four wheels, in most cases. They came back and said that the brakes would be that price, but that I needed to replace all of these other things, and the total would be around $450. While I waited they told countless other customers exactly the same thing, so I had a bad experience with that chain.

Do you do all of your business there?

I just saw this question, sorry. I do tend to go to Brake Masters a lot. I've actually had a good experience with this one (and one in Los Angeles I used to go to). I don't trust hardly any service places, to be honest. I went to some indie one way out in the middle of nowhere for a transmission fluid flush and I don't think they ever did it...according to how dirty my fluid was not long after.

Atheria

Atheria 08-08-2012 11:45 AM

Thank you JTLEMON and to all of the mockers...GRRRR
 
Quote:

Originally Posted by jtlemon (Post 318538)
I am not an expert on toyota's however I am an ASE certified master technician and a GM master technician and here is my two cents:
1- Automatic transmissions do not have a "neutral gear" when they are in neutral none of the clutches are applied and everything is basically freewheeling. what wears in an automatic transmissions is the clutches, and they only wear if they are slipping (ie low hydraulic apply pressure), or during the brief moment they slip as they they are applied, until they are fully applied and the assembly is now rotating at the same speed. the only wear you are doing to the transmission is the additional shifting, which is nothing to be too concerned about.
2- the manufacturer will not deny a warranty claim because you have been shifting into neutral. i have seen GM warranty transmissions that were physically broken in half from abuse. the vehicle data recorders that are on the vehicles give us a snapshot of up to 2 min of data when a dtc occurs, and it is a pretty limited amount of data we have.
3- as long as the engine is running, the transmission pump is providing lubrication. chrysler in particular does not run the pump in park, but all transmissions run the pump in neutral and will be lubricated.

In short, i wouldn't be afraid of damaging a transmission by putting it in neutral, no matter how new or old the car is. modern automatic transmissions are extremely robust and can handle a surprising amount of abuse. To put your mind at ease, I work primarily on oil field trucks that spend most of their time off-road and see more abuse than people can imagine, and it is surprising how few failures we see.

Although, out of fear, I have switched back to not coasting in neutral, your response made me feel better, thank you. My boss did say though (but he's also not a mechanic...hahah) that although my automatic 2008 Scion's engine may be pumping some transmission fluid even in neutral, that it wouldn't pump out as much as really needed because the car would "think" it was stopped and not moving at 40-60 mph. Is that true?

And to all of the psychic mockers. :p I am the real deal, but I don't specialize in tuning into my car's transmission. And, psychics are not given things like winning lottery numbers because that is not the right use of our gifts. Also, when I am emotionally attached to the verdict (i.e. hoping to become a millionaire) I have a hard time getting clear information. My desire makes my logical mind get in the way. Warner Bros. tested me on camera and was willing to spend millions on a TV show in 2007, so you can ask them. :p If not for the stupid Fox Network, I'd be driving an Aston Martin right now...not that I don't love my Scion. :D

Atheria

Xist 08-09-2012 07:18 AM

Quote:

Originally Posted by Atheria (Post 320630)
I just saw this question, sorry.

Ah, good to hear from you. I was feeling unloved! :D

Atheria 08-09-2012 10:31 AM

Awwww.....don't be hurt. I love you boys! LOL


All times are GMT -4. The time now is 08:44 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com