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Old 03-15-2010, 09:56 AM   #1
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Coasting in neutrel

Ok, so I have been reading about people coasting in neutral and some have said that you shouldn't do it in an automatic tranny vehicle, but I did it all day yesterday in my automatic Ford Ranger and it worked great. If my tranny seems to not mind it could I still be messing something up?
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Old 03-15-2010, 10:29 AM   #2
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There's nothing wrong with neutral coasting in an automatic, as long as the engine is still running. That strategy can save quite a bit of fuel. When you shift back into Drive, you should rev-match, which will reduce the amount of work your transmission has to do. Rev-matching just means giving it a little gas so it's already at the right RPM rather than making the transmission bring the engine up to the right RPM.

If you're doing it with the engine off you're likely to damage the transmission from overheating and/or underlubrication. Most automatic transmissions have their oil pump driven by the engine and depend on that oil circulation.
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Old 03-15-2010, 10:37 AM   #3
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Holycow- Thanks again for the info. This is great news, because it seemed like my truck was just fine with it and it made sense that it had to be saving gas!
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Old 03-16-2010, 06:07 PM   #4
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I know it's popular here to shift into neutral in their automatics and I have been at times guilty of doing it as well but I should warn you that there really is a risk to damaging the transmission.

Read this thread about the volvo:http://www.volvoxc.com/forums/showthread.php?t=11149
http://forums.swedespeed.com/zerothread?id=127972

Basically Volvo cars made between '01-'03 maybe earlier and maybe later had a feature where the car would shift into neutral when you press on the brake and come to a stop in order for the car to save fuel. The car would then shift back into gear when the driver let up on the brake. The problem is, these cars' transmissions would go bad after only 40K miles so Volvo patched the transmission software so that the transmission would always stay in gear and this seems to have resolved the issue with Volvo transmissions prematurely failing.

So just keep in mind that doing such a thing really could cause one's transmission to grenade. The thing I didn't mention though but is in the threads I linked to was that part of the problem was that since it didn't shift into gear until the brake was let up on was that you could get into a situation where the car thinks you want to slow down so it shifts into neutral but then you surprise it by asking to accelerate after a brief moment of deceleration, so it hastily shifts into gear, causing a notorious "clunk" in the transmission to be heard. Despite me being pretty sure my car's software is patched, I've heard this clunk under numerous occasions though it's usually heard when shifting out of reverse and into drive or shifting at the wrong time with the Geartronic. So chalk it up to software or an undersized transmission, fact is, you could put a lot more extra wear on the transmission by shifting back and forth into neutral and drive.

All I can suggest to you is to tread lightly and be able to accept the fact that you may very well damage the transmission or reduce its useful life.
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Old 03-16-2010, 07:22 PM   #5
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FWIW, I've been doing this with a Geo Metro automatic and (knock on wood) have had no problems in the last 65k miles. OTOH, I have an '84 Lincoln Town Car and an '83 Cad Eldorado sitting in my driveway right now with dead transmissions...
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Old 03-16-2010, 07:40 PM   #6
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Did you neutral coast in the Town Car and Caddy?

My GMC hasn't had a problem in nearly 20,000 miles since I started neutral coasting, now with a total of 194,000 miles on it, even though the 4L60E is claimed to be failure-prone in the full size pickup.
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Old 03-16-2010, 08:00 PM   #7
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From time to time, yes I did. Actually, I EOC'd the Town Car some...should have known better...guess it was a case of "bad brain". Never EOC'd the Cad, and rarely neutral coasted it after I discovered it had DFCO, figure it just died a natural death, but can't say for sure...
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Old 03-16-2010, 08:02 PM   #8
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Well hey, we can't know if something is bad unless we've got somebody to test it. It's better to trash an older vehicle than a newer vehicle, though it's going to suck to have to replace those transmissions.
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Old 03-24-2010, 04:30 AM   #9
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transmission shmansmission

http://providence.craigslist.org/pts/1652156001.html

maybe the volvos don't rev match say like the nizzan 370x


by the way my not so bright x-landlord used to try to put it in nuetral in his maxima at lights "to save gas"

I pointed out that his rpms were higher than when he had the car in drive..

he said he always got bad mileage

I love the guys who are too umm, lets say smart, to stop their cars all the way before they put them into gear(automatics when reversing) and slam it right into drive like they won an award at doing that at the cool olympics. I just laugh at this. cause there's usually no convincing them other wise
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Old 03-24-2010, 08:15 AM   #10
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In my younger days I would replace my own transmissions. That is no easy task. I've replaced transmissions in my Buick and my 74 Chevy.

I remember that hardest one was replacing the transmission in my 74 Chevy pickup. I had to get somewhere that evening, and I had no help. I put a THM-350 transmission (purchased used for $20) on my chest, and slid under the truck. Then I had to kinda bench-press it into place, and support it while I tried to get the bell housing bolts started. Not an easy task. Being a poor college student I pressed on though.

Maybe I'm getting a bit old, but I would never try to do this on my own again.
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