Strange tranny behavior (I think).

[5280tunage]

Just completed my first major trip, about 6.5hrs of driving. All in all, this thing is great, comfortable, super peppy, great response. Only three issues I had, Sync 3.4 usability, crosswinds that made this thing feel like I was driving an RV, and the tranny. All in all the tranny was comfortable as I'll get out and did great on mountain passes, until.... Was doing about 82mph, 10th gear, had a semi in the right lane that needed to get over for someone merging on. Car was driving via ACC, slammed on the gas, and had this nasty hard shift that basically shook the car. It found 8th gear and accelerated fine, but it scared the wife it was so bad and frankly, I didn't like it much.

I did try searching through the forum and found a few articles, they just didn't seem to be the same situation or experience.

Anyone experience this? Is it normal with this 10speed? Was running in normal 2WD mode, no programming, etc. subsequent slams produce similar responses. Never had issues like this so far, had it since Nov.

On a side note, even with crazy winds, several passes, and cruising above 80mph most of the time (with ACC), I managed to maintain around 21mpg. Well over 50% better than my previous V8 rig with with multi-displacement tech. Very happy there.

 

[Soliyou]

I had a similar experience on a long trip last year in December.

It has been fine since then but also I haven’t had any long trips after that one.

 

[5280tunage]

Thanks for the response, glad I'm not the only one, but forces like that, on a drive train cannot be good. Just didn't seem right, curious if anyone else experienced this and had it looked at.

Also forgot the obvious, tranny temp was as stable as always, no issues there.

 

[Soliyou]

Tranny temp gives the temperature of the fluid at the location of the gage, but there could be a component that doesn’t get enough oil and may overheat. Most of us who got this jolt had it on a long trip after several hours of driving.

I am not an expert though, but I surely hope that this is not the case.

 

[Fozzy]

If you where in 10th gear doing 80+ your RPM’s where nothing. Then you punch it and it drops 2 gears and raises the RPM with a hard shift. Sounds normal. I’m surprised it didn’t go to 7th. (I bet it did) 7 is 1:1. Or it may have gone to 7th and quickly to 8th. That sounds more like it to me with my experience with the 10 speed. Three gear drops and one up is alway pretty aggressive and awkward as it looks for the right gear. I would also bet you don’t drive it very aggressive normally as the transmission adapts to your driving style.


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[5280tunage]

If you where in 10th gear doing 80+ your RPM’s where nothing. Then you punch it and it drops 2 gears and raises the RPM with a hard shift. Sounds normal. I’m surprised it didn’t go to 7th. (I bet it did) 7 is 1:1. Or it may have gone to 7th and quickly to 8th. That sounds more like it to me with my experience with the 10 speed. Three gear drops and one up is alway pretty aggressive and awkward as it looks for the right gear. I would also bet you don’t drive it very aggressive normally as the transmission adapts to your driving style.


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In some ways you may be correct, but I looked down at the bezel a split second after I felt and heard the crazy pop, the bezel showed 8th. Regardless. It was jarring, it scared my passengers which in my 15 or so previous cars did not feel like this. I mean taking a race built Acura from 6 to 4 didn't feel like this and you're talking 8k+ rpm.

Regardless, my normal in town driving is good off the line but soft for normal operation. In a passing scenario I'm not sure I understand why that might lead to a rough downshift.

Just trying to understand if others have experienced n this and if so, have they found issues via service?

 

[wakeboarder]

Running in ECO mode with ACC makes the throttle a lot less aggressive. I know it doesn’t directly address the issue, but it may help prevent it from happening again.

 

[Zig10]

Same thing has happened to me twice. Both in the mountains around 75 MPH, going up a grade. First time it downshifted so hard I swore the transmission case split. The second time (around 8 months later) it wasn't quite as violent, but still was abrupt.

In general I notice much rougher shifts when the vehicle is in eco mode, so I just stopped using it. Seems to be behaving much better now.

 

[5280tunage]

Running in ECO mode with ACC makes the throttle a lot less aggressive. I know it doesn’t directly address the issue, but it may help prevent it from happening again.

So does ACC automatically put the vehicle in Eco mode? I hardly ever change the drive mode, so it was in normal mode originally.

 

[5280tunage]

Same thing has happened to me twice. Both in the mountains around 75 MPH, going up a grade. First time it downshifted so hard I swore the transmission case split. The second time (around 8 months later) it wasn't quite as violent, but still was abrupt.

In general I notice much rougher shifts when the vehicle is in eco mode, so I just stopped using it. Seems to be behaving much better now.

Thanks for the response. I literally thought my trip was over when I felt that. Have to watch it though, there's no way that's good for the mechanical systems.