P vs. N

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When driving in very hot weather is it best to keep the gear in N neutral, or P park -- when stopped at a stop light? In order to help keep the automatic transmission/transaxle cooler.

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On 23 May 2005 18:40:07 -0700, snipped-for-privacy@yahoo.com wrote:

LMFAO bwhahahahahahahahahaha
get some certification
HURC ast
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Putting a car in park and neutral are the same thing, except in park, the drive shaft is locked when the car is in park.
The answer is leave it in D. You won't build up much heat in the transmission when it is in drive and you are completely stopped. And if you change the gear, you are more likely to accidentally put it in reverse and whack the car behind you.
Jeff
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Think this over again. Driving around in 120 Degree weather. 120 feels like to the skin. It gets that hot in Oklahoma, you bet.
Knowing that heat is what kills transmissions. Wouldn't you want to shift into Neutral whenever you can in order to help aid in transmission cooling? The less heat the better in there. Of course the best thing is an oversized transmission cooler. And I know I'll install one as soon as I get the chance to. We are heading into summer now.
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The heat mostly builds up when you are driving, especially under load.
do a search on the web for transmission + cooling + stopped or something like that. Notice how there are no sites recommending this. Or try looking in your owner's manual. Does it say anything about putting the transmission in neutral?
Jeff
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Check out the Aamco site. It recommends such practice.
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On 23 May 2005 21:57:16 -0700, snipped-for-privacy@yahoo.com wrote:

EVERYONE used to recommend that. Don't hear it as much anymore, but your transmission does build up heat while stopped and in gear. The rule of thumb some years ago was if you were going to be stopped for more then a minute, put it in Neutral (or Park), otherwise don't worry about it. I treated cars both ways, that is, put in Neutral at every stop, and didn't do that hardly ever on other cars... didn't seem to make any difference to how long the transmission lasted, they all seem to last forever for me.
As to your original question, ... at a stop light, just put it in Neutral, not park, it's much more trouble to move it in and out of park and since you have to put your foot on the brake on any of the newer cars you might as well just use neutral and keep your foot on the brake.
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wrote:

If you've gotta keep your foot on the brake anyway, why bother shifting gears at all?
Truth be told, if you're *that* worried about heat buildup, wouldn't shutting the engine off at redlight be just as sensible? Even with the trans in N or P, it's still going to build up heat sitting there.
I'm no expert, by any means, but I've never had a problem with just leaving it in drive, and holding the brake at a stop.
Hell, the way I see it, regular fluid changes and a good external trans cooler (bigger is better) would do far more to prolong transmission life than shifting into N or P at a stoplight will.
-LMB
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Neutral is a good choice.
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snipped-for-privacy@yahoo.com wrote:

Neutral is a terrible choice. Leave the bands & clutches engaged, idle in "Drive". Much less wear than dis-engaging & re-engaging all the clutch packs, bands & servos. The only slipping/stalled component at idle in (D) is the fluid connection at the converter... leave it that way. With electric fans, the cooling system of the vehicle is more than adequate.
Rob
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On Tue, 24 May 2005 16:06:48 -0400, trainfan1

It really makes no difference unless you are going to sit a long time.
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wrote:

Aamco recommends this only when you are sitting still for an extended period of time. It says doing this for normal driving situations could be an unsafe procedure, given the extra shifting required and the potential for error (like putting the car in reverse and slamming the car behind you when you start).
So my answer is correct. It is best to keep the car in gear at a stop light.
Jeff
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Jeff wrote:

Well I agree with you for general driving. However, if you are going to spend a lot of time stopped, or idling around on a very hot day, shifting to park might be a good idea. I would never do it in normal traffic, or even heavy stop and go traffic. However, I did severely overheat a transmission on my farm truck one day when I was observing some activity in a field. It was 100 degrees and I was moving occasionally and then sitting stopped with my foot on the brake for an extended period (and the AC was on full blast). The actual load on the transmission was minimal. Unfortunately this truck did not have an auxiliary transmission cooler.
Ed
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wrote:

Not to mention the extra stress you'll put on it by changing gears, mainly in the clutches and bands in there. (I.E. In gear, they're applied and holding, when in neutral, they're allowed to return to their "at rest" positions... each time an apply device is applied, it generates wear and tear on it.)
-LMB
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If you are that concerned, I would recommend installing an extra cooler in line with the factory installed cooler.
If changing gears will help ease your mind, I would recommend selecting the gear that the fluid gets checked in.... this will ensure that fluid is flowing through the torque converter (where most of the heat is generated) and into the cooler lines.
Other heat reducing measures you can take. Avoid using the gas pedal to hold the car on inclines. Avoid using overdrive in stop and go or low speed driving. Avoid using overdrive in towing applications. Have the transmission serviced at it's recommended interval and keep the radiator cooling fins clean.
HTH

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Re: P vs. N Group: alt.autos.ford Date: Tue, May 24, 2005, 6:21am (EDT+4) From: snipped-for-privacy@tenalpsulet.net (JimWarman)
Avoid using overdrive in stop and go or low speed driving.<<<<<
Why? OD dosent kick in until 40mph on my car.
Eric
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It has something to do with the way the bands and gears mesh together.
Honestly I'd by 1,000 times happier if my car were equiped with a manual 5 - Speed gearbox instead of the dumb slush box that I honestly don't care for. My car isn't even sold with the 5 Speed. The North American car market is about as dumb as it gets. For the most part, American car consumers don't know how to select the better cars.
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On Tue, 24 May 2005 05:09:52 -0400, snipped-for-privacy@webtv.net (Eric Toline) wrote:

If your vehicle's equipped with a transmission/transaxle like the AXODE, you can 'switch' overdrive off and on (the tranny will still shift into all 4 gears with OD "off" but, with it on, with the conditions right (crusing, brakes off, engine warmed up) the torque convertor will enter lockup (meaning a pressure plate inside the convertor case will engage, creating a direct mechanical linkage between the engine and transmission, instead of the fluidic coupling normally used. ) If you leave it engaged during stop and start, that pressure plate will be applied and released fairly often, building up more heat, and causing more wear on it.
-LMB
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Louis M. Brown wrote:

Close, w/ OD off you only get 3 forward gears, + lockup in 3rd.

OD on or off won't matter too much, except lock-up may actually occur earlier as it will happen in 3rd gear only. Newer (E) trans converters are modulated, too, computer controlled, and will lock up in 3rd before even getting to 4th under some conditions.
Rob
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On Tue, 24 May 2005 16:13:45 -0400, trainfan1

? I could have sworn my cousin's windstar had all 4 forward w/OD off,

Which is why I prefer the older vac modulated / TV cable driven trannies...no computer deciding if you're allowed to manually downshift or not (which, in theory, sounds good... it'll possibly prevent damage to the trans, but what happens if the computer fails / glitches out? AFAIK, you'd be limited to 2nd gear, if lucky, )
And yea, I know convetor lockup is now computer controlled (didn't used to be in the oldTV based AOD (RWD) and AXOD (FWD) trannies... Or in the C5, for that matter (it used centrifugal lockup, so it'd literally lockup in all 3 forward gears, if the RPMs were high enough...)
Back to the original subject, I, myself wouldn't bother putting the vehicle in Neutral at a stop. If I was going to be there long enough to get my foot tired from holding the brakes, I'd just shut the damned engine off.
-LMB
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