Shifting into neutral

[Falcon_LS]

I have a habit of shifting into neutral and applying the parking brake whenever I stop at a traffic light. I also shift into neutral if I'm stuck in a traffic jam for a good couple of minutes. I do this to reduce load on the engine, and let it idle more freely.

Somebody was telling me the other day that this is hard on the transmission - not shifting into neutral, but shifting into drive from neutral. Just wondering if there is there any truth to this, and is it better to just apply the brakes in drive?

Thanks!

 

[whip]

If it was me, I'd leave it in drive. The engine/transmission are designed to idle in drive.

 

[SrDriver]

I am sure that would cause wear.

When I lived in Korea vehicles would shut off their engines and lights at red lights.

 

[demarpaint]

Leave it in drive, unless you plan on sitting at a light or in traffic not moving for a long time. It causes wear on linkage, and shock on the drive train every time it is shifted back into gear. As already mentioned the transmission was designed to stay in drive even when stopped at a light or in traffic.

 

[Falcon_LS]

Thanks for all the input.

Time to change my driving habits slightly.

 

[The_Jeff]

Also the parking brake cables stretch pretty easily. They are usually a flimsy mechanism. You could at least use "park" instead of "neutral" and save wear on the e-brake.

If you're going to go from neutral to drive, do it when you're ready to roll with the brakes off so the car's movement soaks up some of the (soft) bang into gear.

 

[Falcon_LS]

Originally Posted By: eljefino
Also the parking brake cables stretch pretty easily. They are usually a flimsy mechanism. You could at least use "park" instead of "neutral" and save wear on the e-brake.

If you're going to go from neutral to drive, do it when you're ready to roll with the brakes off so the car's movement soaks up some of the (soft) bang into gear.


My Grand Marquis has an automatic parking brake release, so whenever you shift into drive, the e-brake is released. On the others, I often release the e-brake before shifting into gear, but now that you mention it...

I also have a habit of applying the e-brake whenever I park (even on a flat surface). Whilst shifting into park locks the transmission, I feel it's better to have the weight of the car resting on the parking brake vs. the transmission. Although now it doesn't seem like such a good idea, considering the cable stretches, given the temperatures it sees here.

 

[demarpaint]

Using the parking/emergency brake to park is a lot different than using it every time you stop at a light. Don't use it when you stop at lights, use it when you park. Or use it only when you park on an incline or decline. The cables do stretch, but in normal use it isn't going to be all that bad.

 

[JHZR2]

We do this on all our MT and ATs. We've yet to have to do an AT rebuild... and have >>200k on multiple toyota and MB ATs.

 

[Spazdog]

In some older cars with automatic, I had to use a lot of force to get the car off the parking pawl if the car was left resting on it. Doesn't seem as difficult on more modern cars.

If I'm going to be stopped for awhile, (like in a drive-thru or something) I'll shift to neutral. I always figured the extra "shock" on the drivetrain was less than just leaving it in drive and generating more heat. Plus there's less chance I'll not be paying attention and roll into the car in front of me. But for a traffic light, I just leave it in Drive.

 

[The motor guy]

I would leave it in drive. If you put it in neutral and set the parking brake then you probably don't have your foot on the brake so people aren't going to see your brake lights and could cause you to be rearended due to the fact that they might think you are starting to move when you are really just sitting there.

 

[bluestream]

As mentioned, shifting causes more wear tha leaving it in drive. I have learned myself and no longer do that..

 

[Craig in Canada]

There's nothing wrong with the theory of shifting to neutral when waiting at a light, but don't do it too soon. Remember that you'll be unable to avoid a rear end collision if someone behind you doesn't stop. If you're talking about steady state after a group of cars has stopped, then it's probably safe.

Personally, I wouldn't bother with the p-brake. Why aren't you using the normal brakes in this instance? The only reason I can think of avoiding it is to avoid hotspotting the rotors and/or creating pad deposits by leaving hot pads clamped in one place. If you're not driving "hot" and your braking system isn't under-designed then this really shouldn't be an issue. You also want to keep the back of the car lit up clearing showing that you're stopped.

It's better that you're a frequent p-brake user than someone who never uses it. Those are usually the people with seizures and cable breaks. There is such a thing as over-use, though. On a lot of cars replacing a p-brake cable is a truly epic PITA. As for routine stretch, I think most can be coarse adjusted at the p-brake and fine-adjusted at the lever - not a big deal until it breaks.

I believe that shifting to N is a lot fewer moving parts than shifting to P. Do you know much of the specifics about your transmission? For instance I know that in P a ZF A5S440Z (BMW E39 V8) sends an enormous amount of ATF through the heat exchanger while in N it's a significantly slower flow. Whether that is actually going to matter to anything is another matter.

I also wouldn't worry about the "driveline shock" of shifting to D from N in a fully warmed up, low idling scenario though I guess I'd probably do it after letting go of the brakes, assuming your shift console lets you shift N to D without applying the brakes. Just make sure you don't get on the throttle before it's fully in gear.

Say, that's another reason not to go to P - lots of cars won't shift out of P without pressing the brakes. So at a stoplight you'd be going brakes, P brake, P, off brakes, wait, brakes on, release P-brake, P->D, release brakes and drive. Guh... Compare this to stop, D->N, release brakes, N->D, drive. Or compare to not bothering with N at all.

I drive stick, so I don't do any of this personally...

 

[Towncivilian]

I sometimes do this at very long lights (or shift into park). Probably should just stay in drive now.

I also use the parking brake every time I park; I come to a complete stop, shift into neutral, engage the parking brake, release foot brake, wait for car to settle (i.e. stop the tiny roll one sometimes gets after shifting into park without parking brake), then shift into park. I have found that this makes it significantly easier to shift from P whereas it required quite a bit of force when not using the parking brake. Should I omit the "neutral" step here?

 

[UNC017]

Originally Posted By: Falcon_LS
I have a habit of shifting into neutral and applying the parking brake whenever I stop at a traffic light. I also shift into neutral if I'm stuck in a traffic jam for a good couple of minutes. I do this to reduce load on the engine, and let it idle more freely.

Somebody was telling me the other day that this is hard on the transmission - not shifting into neutral, but shifting into drive from neutral. Just wondering if there is there any truth to this, and is it better to just apply the brakes in drive?

Thanks!



When you shift into drive, clutches apply and so there's definitely a little burst of wear. When you idle in gear, nothing is actually wearing but the fluid in the torque convertor is being sheared and heated. The transmission cooling system can usually get rid of that heat just fine, though.

If it were me, I'd do different things based on time. Idling at a traffic light for 30 to 45 seconds- leave it in gear. Idling in the bank drive-through for 3-4 minutes- put it in neutral, especially in hot weather. Any stop longer than 5 minutes- shut the engine off completely unless its so hot the A/C is mandatory in order to stay in the car.

 

[demarpaint]

Originally Posted By: 440Magnum
Originally Posted By: Falcon_LS
I have a habit of shifting into neutral and applying the parking brake whenever I stop at a traffic light. I also shift into neutral if I'm stuck in a traffic jam for a good couple of minutes. I do this to reduce load on the engine, and let it idle more freely.

Somebody was telling me the other day that this is hard on the transmission - not shifting into neutral, but shifting into drive from neutral. Just wondering if there is there any truth to this, and is it better to just apply the brakes in drive?

Thanks!



When you shift into drive, clutches apply and so there's definitely a little burst of wear. When you idle in gear, nothing is actually wearing but the fluid in the torque convertor is being sheared and heated. The transmission cooling system can usually get rid of that heat just fine, though.

If it were me, I'd do different things based on time. Idling at a traffic light for 30 to 45 seconds- leave it in gear. Idling in the bank drive-through for 3-4 minutes- put it in neutral, especially in hot weather. Any stop longer than 5 minutes- shut the engine off completely unless its so hot the A/C is mandatory in order to stay in the car.



I do pretty much the same things you've outlined.

 

[mechanicx]

I wouldn't bother shifting into N at a stop light and I'd definitely not set the parking brake. Just use the service brake. I don't think shifting into N causes more internal wear. It may cause slightly more wear on the shifter linkage and the manual body, but shifting into N all you are really doing is eliminating line pressure to the forward drive clutch which would be idling when stopped. I think shifting to N makes little difference if any and is waste of time.

 

[Warstud]

As long as the vehicle isn't moving I don't think matters. I do the same thing you do at most stops and only use the brake when I start to roll or shift back into drive.

 

[CROWNVIC4LIFE]

I know someone with a 98 GMQ who always shifts into Neutral at every single red light and believe me there are alot of red lights down...The car has 150K miles on it and so far the transmission is just fine.

I have not used my e-brake on any of my cars since the 70's.

 

[UNC017]

Originally Posted By: mechanicx
I don't think shifting into N causes more internal wear.


Well, as originally said, its the shifting back to drive that causes the wear. Its an absolute fact that engaging a clutch pack and bringing the spinning driven turbine of the torque convertor to a stop DOES cause some wear on the clutch.

Now whether or not it makes any difference whatsoever in the life of the transmission is an entirely separate question. I personally doubt that it does... but there is some tiny amount of wear.