Is coasting bad on my Automatic transmission?

[99metro]

When shifting from N to D, you ought to be shifting close to the speed that it would normally shift. For example, a lot of vehicles will shift into overdrive around 37 mph - that is where you should shift back to Drive. It's only a suggestion, not an OMG-the-world's-coming-to-an-end thing.

[Cd]

I have a '93 Civic auto that I've made a habit of coasting in N, but with the engine on.
I have found that shifting back to D at anything under 45-50 mph results in the rpms jumping way up as the car suddenly slows to get into gear. This can be bad if I have a tailgater riding behind me as I coast, since the car will engine brake and suddenly slow.
A couple of days ago I was surprised that I accidentally shifted into R instead of D while coasting along at around 35 - 40 mph. Nothing happened , but I thought this wasn't possible without some sort of damage.

[Cd]

I should add that I had my VSS ( vehicle speed sensor ) go out on the transmission.
Not sure if this has anything to do with any of the N coasting.

[Thymeclock]

Originally Posted by 99metro

When shifting from N to D, you ought to be shifting close to the speed that it would normally shift. For example, a lot of vehicles will shift into overdrive around 37 mph - that is where you should shift back to Drive. It's only a suggestion, not an OMG-the-world's-coming-to-an-end thing.

Please tell us why you suggest this.

Also, please tell us what you think might happen if you don't do this.

[PaleMelanesian]

If you give a little gas as you shift it back into D, you can match the little blip it automatically adds, but with out any added drag. Then ease off the gas as it drops into top gear lockup.

Being a Honda automatic, it probably has the usual "35 mph max" flat-towing specification. I don't EOC on the highway with my Odyssey, but in town I do. Consider that you're getting ~200 mpg at highway speed with the engine idling. That still does a lot to your average.

[afahey]

I do the same thing with my 93 honda dx, it has a auto trans and I find that shifting from N to D at 25mph in urban areas to be nice an smooth. When I shift from N to D between 25 and 45mph I get the down shift. I do find that slightly touching the go pedal while shifting back into D at these speeds to help. When I am shifting into D above 45mph its a smooth shift. I don't EOC but ever since I have discovered this site I have been doing a lot of Engine on Coasting. I hope to see an improvement on my next couple of tanks, from all the coasting I have been doing.

[Thymeclock]

Originally Posted by afahey

I do the same thing with my 93 honda dx, it has a auto trans and I find that shifting from N to D at 25mph in urban areas to be nice an smooth. When I shift from N to D between 25 and 45mph I get the down shift. I do find that slightly touching the go pedal while shifting back into D at these speeds to help. When I am shifting into D above 45mph its a smooth shift. I don't EOC but ever since I have discovered this site I have been doing a lot of Engine on Coasting. I hope to see an improvement on my next couple of tanks, from all the coasting I have been doing.

When you do this, and you feel the jolt (or call it whatever you please), what part of the A/T absorbs what you feel?

[mcrews]

I have had a toyota Avalon(1997) and Infiniti Q45 (2002) for the last 8 years.
So i can only speak to those to makes.
Both of them were perfecvtly fine coasting in neutral. the rpm in the Q45 drops to around 600 which is the dead idle.
the avalon had 215k when I got rid of it (only because the Q45 came along cheap)
the Q45 has 245k on it. Neither tranny has any problems

as a note : I drove a 200x taurus for a customer for a week. It did not like being in neutral while moving. rpms stayed in the 2000 range

[user removed]

I EOC (engine on) the Altima all the time, even at 70 MPH shifting back into drive is a non event. The torque converter does not lock up until you give it some gas. It takes about two seconds for it to re-engage the "gears" (CVT). I have shifted back into drive as high as 80 MPH and even at that speed the RPM after re-engagement is only around 2000.

regards
Mech

[mcrews]

I 'think' that (from my expereience) the Nissan/Infiniti products do fine.