shifted into reverse accidentally driving automatic

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Originally Posted by clinebarger
Originally Posted by tookien
Originally Posted by clinebarger
Originally Posted by tookien
Upon some further research, would the transmission control unit not detect this change at that speed keep it at neutral?



On a lot of units....Reverse actuation is 100% Hydraulic, No electronics involved.



doing some research it seems they added Reverse inhibit to transmissions in mid-90's and up which is electronically controlled.


Who's "They"?



car companies.
 
I used to hyper mill on cars with carbs in the 70's to 80's. Whether it really saved any gas....I don't know? My favorite coaster was a 1964 Buick Wildcat with the 400 ci engine and a highway cruiser gear. That thing would hit in the 90's coasting down some moderate hills. Stopped doing this altogether in the 1990's when I inadvertently slammed my '85 Ford Ltd into Reverse at about 40-50 mph. It stalled. It continued running fine until it was sold a couple years later. Once was enough.

Using 2 feet on an automatic? I do it all the time on my automatic sedans. I use the same two feet on my manual 6 speed too. Any time I'm slowing or might have to slow in an instant, my left foot is hovering over the brake pedal by about 1/2"....while my right foot is feathering the accelerator pedal. Who knows when you might need to accelerate or break out of a situation that occurs unexpectedly? I also like to give 5-7 car lengths on the highway but most others won't let you drive with that wide a safety margin. You can bet that when on the highway in tighter traffic (1-4 car lengths caused by someone else) I have both pedals ready to react until a 5 car length cushion is re-established. I never touch the brake pedal unless I'm purposely braking.

Been doing this for 20-25 yrs now and never a hiccup. In my mind it's a safer set up than having to remove your right foot off the gas and then drag it over to the brake pedal....which wastes time. Now if you're used to driving heel/toe you can cover both pedals to some extent with the right foot....though meant specifically for manual transmissions when down shifting.
 
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Originally Posted by PimTac
There is no reason to put the transmission in neutral going downhill, absolutely none. It's sounds like you got lucky. It's a bad habit that should be stopped like using both feet for throttle and brake.


Actually using both feet for gas and brake is not all bad... NASCAR drivers have done it a whole lot. And I bet irl drivers have too.

I had to learn how to use my left foot and leg by itself while driving. Because my right leg would hurt so bad from my illness that I just couldn't take it anymore. I did this learning while out on Rte 17 where no one else was really around at all. I had to sit facing the middle of the car. That way my left foot would not hit the brake pedal. I generally have not had to use my left leg and foot often. But it is nice to be able to do this.
 
I did that once with a 1965 Delta 88 and the car rear wheels locked up and I put it back in drive and had no problems. I doubt you hurt your vehicle. Do not use neutral to coast downhills with automatic transmission cars since most are not made for it and you will ruin your transmission over time. The only vehicles that should be thrown in neutral are the ones that say it's ok to tow them and it should be stated in the owners manaual. People with RV's that tow vehicles behind them often pick vehicle that can be towed in neutral without removing any drive shafts or any other parts.
 
Originally Posted by bbhero
Actually using both feet for gas and brake is not all bad... NASCAR drivers have done it a whole lot. And I bet irl drivers have too.
I think driving style between track racing and street driving is just a wee bit different so I'm not sure all techniques cross over. In much of racing, they are either on the throttle or on the brake and want to eliminate even miniscule delays in moving their foot from one pedal to the other, hence using two feet.
 
Originally Posted by emg
Originally Posted by spk2000
It is called hyper-miling trying to get super duper fuel economy which is not always the safest thing to do.


How would that work? In neutral, the car is burning gas to keep the engine idling. In drive in most (all?) modern vehicles, the engine is burning no fuel if your foot's off the gas.

Respectfully, this is incorrect. If you hook a Scangauge (or other similar device) up and drive with it, you will see that the engine does in fact consume fuel while decelerating or idling (foot off pedal). It does so in Neutral as well, as you suggest. For the record, I keep this hooked up to the Prius normally, but I've tried it on my wife's Avalon as well, which is strictly conventional. I suppose there might be other conventional vehicles set up differently. These are the four variables I keep up on the display (there are quite a few others from which to choose). GPH on the lower left is, of course, gallons per hour (a/k/a fuel flow). Also, display values here are an anomaly. It's on the Prius here, and occasionally it gives this 0.04 gph reading instead of dead zero. When on the Avalon, and decelerating, there's actual fuel flow showing.
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Originally Posted by Linctex
absolutely nothing



Interesting, and pretty much what I expected, including having about six minutes of unnecessary blabbering and about ten seconds of worthy "testing." It was interesting how the rear-view camera came on and the Parking Assist activated, though. Poor computer -- did its job protecting the fool from himself, but got a little confused while doing so.
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it all depends on the trans and the engine. older hydraulic trans will engage and pull on the engine, stall it, maybe even spin it backwards a few revs. I've seen this. On on a simple chain drive cam, you can restart it. Saw this in an E250 a couple of years ago. A newer chain or belt cam with tensioners may skip time leaving you with a repair bill or a really big repair bill. In some cases at highway speeds, gearbox carnage can happen. Plenty of evidence of that. Most newer cars with electronic controls have means to protect the trans.

An automatic is an automatic. I'd leave it in gear and stop putting wear on the clutches. If you want to have real control, you can't beat a nice manual.
 
On every vehicle from my 06 Santa Fe forward my scangauge will show "Open Loop" status and will turn off the injectors when coasting as long as the RPM isn't too low which is basically anything above ~1000rpm or so (varies on the vehicle). So putting it in neutral would actually waste fuel coasting instead of letting the engine coast in gear keeping the RPM's up.
 
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Originally Posted by StevieC
On every vehicle from my 06 Santa Fe forward my scangauge will show "Open Loop" status and will turn off the injectors when coasting as long as the RPM isn't too low which is basically anything above ~1000rpm or so (varies on the vehicle). So putting it in neutral would actually waste fuel coasting instead of letting the engine coast in gear keeping the RPM's up.

Next time I get home (I mostly 500+ miles away for the next few months...), I'll recheck the Avalon. Don't recall seeing open loop, but I don't leave that reading visible usually anyway. I recall small fuel flow while coasting. Didn't give it much thought, but I assumed it would keep the engine at a controlled rpm and keep the cats from cooling down to where they can't do their clean air magic. Now I'm curious!
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I feel an OCD attack coming on. . .
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Originally Posted by emg
In drive in most (all?) modern vehicles, the engine is burning no fuel if your foot's off the gas.
Sounds like you're confusing hybrid vehicles with non-hybrids. An automobile engine requires fuel to run, even at idle.
 
Originally Posted by ekpolk
It was interesting how the rear-view camera came on and the Parking Assist activated, though. Poor computer -- did its job protecting the fool from himself, but got a little confused while doing so.
The rear-view camera comes on because of the gear-selector position, nothing more. Not sure about the Parking Assist feature though.... As for that "fool", that video has put quite a bit of money in his bank account. He did it for monetary reasons only, not educational ones !
 
I have a 2016 Dodge Ram with the 8 speed German trans. the selector is the round knob , right beside the round selector switch for the heat/ac fan speed.

twice, I have switched the trans into reverse at 50+ mph.

not paying attention and just wanting to change fan speed. 20,0000 miles and 2 years later, seems no harm done and looks like the engineers anticipated dumbazzes like me.
 
Originally Posted by hallstevenson
Originally Posted by ekpolk
It was interesting how the rear-view camera came on and the Parking Assist activated, though. Poor computer -- did its job protecting the fool from himself, but got a little confused while doing so.
The rear-view camera comes on because of the gear-selector position, nothing more. Not sure about the Parking Assist feature though.... As for that "fool", that video has put quite a bit of money in his bank account. He did it for monetary reasons only, not educational ones !

I'm very well aware of how that works. I imagine he'd disagree with my characterization of him. It seems that you do -- that's entirely your business. As for me, I'm standing by my assessment, thank you. . .
 
it seems no damage was done to the trans as I was driving all day and carefully checking the shifting, as well as in reverse.

drives exactly the same as before. it seems the computer was smart enough to prevent engaging in reverse and simply kept it in neutral.
 
My understanding of my 2010 Corolla 1.8L engine is that, when the instant MPG meter goes to 99.9 MPG, it's free-floating the valves and not burning any gasoline. I got that off of a Toyota forum, so it may not be correct.
 
Originally Posted by StevieC
On every vehicle from my 06 Santa Fe forward my scangauge will show "Open Loop" status and will turn off the injectors when coasting as long as the RPM isn't too low which is basically anything above ~1000rpm or so (varies on the vehicle). So putting it in neutral would actually waste fuel coasting instead of letting the engine coast in gear keeping the RPM's up.

It might be an SUV/Truck thing, where the emissions testing protocol allows fuel cutting and the subsequent catalytic converter cooling? My 03 Tracker did cut fuel down to 12-1300 rpm in any gear when your foot was off the gas. My Focus is nuts where it uses more fuel while coasting in gear(~130mpg), than when coasting in neutral at idle(~180mpg)... Just to keep the cat lit up. It will cut fuel decelerating at like 4k+ rpm, but I'm never driving 180 kph where that would be useful in top gear...
The Outback(a CAFE SUV/Light truck) says its cutting fuel on the dash instantaneous fuel mileage gauge, and the CVT will hold the rpms around 12-1300rpm while decelerating so perhaps it actually is. When I tried shifting to N while coasting, it went into a high idle mode and showed fuel consumption so I don't bother doing that anymore.
 
Originally Posted by tookien
it seems no damage was done to the trans as I was driving all day and carefully checking the shifting, as well as in reverse.

drives exactly the same as before. it seems the computer was smart enough to prevent engaging in reverse and simply kept it in neutral.


The U241E has no such electronic control! There isn't really a lot of different methods employed for a 4 speed automatic transmission/transaxle to actuate reverse!
Honda automatics would be the outlier here....They use a shift fork, synchros, & a shift cable just for reverse, It's identical to how a manual trans achieves reverse....Without the clutch part! That's why they whine in reverse if anyone was curious.

There is NO electronic troubleshooting information for a U241E not having reverse. If the ECU was capable of inhibiting reverse.....It can also malfunction & cause a NO Reverse condition.

With the advent of 5,6,8,9,10 speed units.....There was no longer room for single purpose components & simplified hydraulics. Electronic reverse control was a by-product of this.

You could have very well cause Zero damage to the unit.....Though I wouldn't make it a habit as it can & will cause burnt frictions!

The Direct Clutch is what drives the unit in reverse.....Acts as the Input. The Direct clutch is also ON in 3rd & 4th gear., This was the reason it didn't shudder!
The Lo/Reverse clutch was trying to come ON as well......But it doesn't have much leverage against a high speed object with the weight of the vehicle on it.


Someone here mentioned a Trailblazer/Envoy which would have a 4L60E.....This unit will Shudder like mad if put into reverse at speed. Because they have no "Direct Clutch", They use a Reverse Input Clutch to drive reverse. In high gear.....The reverse input housing is held stationary. So engaging reverse will cause a bind with the reverse input clutch having a lot of leverage!
 
I was riding with my boss in a 2013 ford ranger when he stopped , put it reverse, let off the brakes and we coasted downhill going forward at about 30 MPH. He hit the gas and all that happened was the engine stalled. He is an engineer so we don't expect any better
 
Originally Posted by clinebarger
Originally Posted by tookien
it seems no damage was done to the trans as I was driving all day and carefully checking the shifting, as well as in reverse.

drives exactly the same as before. it seems the computer was smart enough to prevent engaging in reverse and simply kept it in neutral.


The U241E has no such electronic control! There isn't really a lot of different methods employed for a 4 speed automatic transmission/transaxle to actuate reverse!
Honda automatics would be the outlier here....They use a shift fork, synchros, & a shift cable just for reverse, It's identical to how a manual trans achieves reverse....Without the clutch part! That's why they whine in reverse if anyone was curious.

There is NO electronic troubleshooting information for a U241E not having reverse. If the ECU was capable of inhibiting reverse.....It can also malfunction & cause a NO Reverse condition.

With the advent of 5,6,8,9,10 speed units.....There was no longer room for single purpose components & simplified hydraulics. Electronic reverse control was a by-product of this.

You could have very well cause Zero damage to the unit.....Though I wouldn't make it a habit as it can & will cause burnt frictions!

The Direct Clutch is what drives the unit in reverse.....Acts as the Input. The Direct clutch is also ON in 3rd & 4th gear., This was the reason it didn't shudder!
The Lo/Reverse clutch was trying to come ON as well......But it doesn't have much leverage against a high speed object with the weight of the vehicle on it.


Someone here mentioned a Trailblazer/Envoy which would have a 4L60E.....This unit will Shudder like mad if put into reverse at speed. Because they have no "Direct Clutch", They use a Reverse Input Clutch to drive reverse. In high gear.....The reverse input housing is held stationary. So engaging reverse will cause a bind with the reverse input clutch having a lot of leverage!




Thanks. that's very informative. I am really interested on the internals of transmissions and will be researching more on this.

All I can say in this case is that there is no obvious damage from my perspective as the car shifts as before and there is nothing out of the ordinary.
 
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