Noise and slight jerk when downshifting from 2nd to 1st

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#21

01-09-2019, 11:49 AM

Cee Jay

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Quote:

Originally Posted by amcdonal86

It seems to be a misconception that the car defaults to starting in 2nd gear. I can assure you, at least on my 2007 model, whether in D or S mode, it always starts from 1st at a stop. All you have to do is count the shifts to 6 to realize it!

What I think is being misconstrued here is that with the transmission in MANUAL, the car will shift down to second gear at a stop by itself while also staying in Manual. That's a damage-avoidance thing.

When in Automatic, yes, it goes into first.

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#22

01-09-2019, 12:04 PM

Brewtech

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Quote:

Originally Posted by Cee Jay

exactly!

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#23

01-09-2019, 01:16 PM

u102768

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Quote:

Originally Posted by Queen and Country

So yours is not going into 7th gear?

On my 5.0 XKR, always going to 1st would be unpleasant and unnecessary.
I have found it depends on how much throttle I apply. In other words I have to request the 1st gear.

If you use SDD to monitor the current gear like I did on both my '07 and '10 XKR's you will find that they drop in to 1st every time as you come to a halt in auto mode.

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#24

01-09-2019, 01:36 PM

Queen and Country

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Quote:

Originally Posted by u102768

you will find that they drop in to 1st every time as you come to a halt in auto mode.

How about on acceleration?

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#25

01-09-2019, 02:47 PM

u102768

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Quote:

Originally Posted by Queen and Country

How about on acceleration?

Here is a video I shot when I first got my '10 XKR. It was mainly done to show the opening and closing of the active exhaust valve but has the current gear displayed as well:

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#26

01-09-2019, 03:07 PM

Brewtech

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Guys... lets be clear... it does go into 1st while in D or DS. Thats not what were discussing. It doesnt go into 1st if you drive in Manual Mode. If youre in D or DS, yes, it will go into 1st. In Manual it will only drop down as far as 2nd. You have to select 1st if you want to The computer is better at selecting 1st and back to 2nd and back to 1st better than you can manually, so in order to avoid user error, it will not drop into 1st unless requested, and if requested, theres a chance that you will shift while at too high speed and you will be in 1st at 5k RPM. So yes, the computer will shift into 1st, but when left to the driver, it wont.

Last edited by Brewtech; 01-09-2019 at 03:14 PM.

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#27

01-10-2019, 03:05 PM

u102768

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Quote:

Originally Posted by Brewtech

Guys... lets be clear... it does go into 1st while in D or DS. Thats not what were discussing.

That is actually what most of this thread is about...

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#28

01-10-2019, 03:22 PM

Brewtech

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Quote:

Originally Posted by u102768

That is actually what most of this thread is about...

oh yeah.

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#29

09-01-2019, 03:23 PM

trkyam

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Just an update,

I did solve this problem..

The transmission was learning to down shift to first prior to coming to a stop due to my aggressive driving style.

Thanks to all the information everyone provided I decided to stop manually downshifting to first as it is unnecessary wear on the
drive train and clutches and also trains the transmission to shift to 1st prior to stop on its own!

Downshifting to first at speed was putting a lot of force on the transmission mounts and drive line causing movement and noise.
I don't think the transmission mounts are designed for that type of shifting.

Last edited by trkyam; 09-01-2019 at 03:31 PM.

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