I was wondering if it'd normal for the gear stick to have a slight movement when it's in 3rd or 4th gear. It moves about 8mm with acceleration and deceleration. 

I replaced 2 engine mounts, the third one (under the battery) seemed ok so I decided not to replace. 

The gear stick still have a bit of movement. I'm wondering if I should replace the third engine mount and if it would make any improvements or this is normal thing with nissan cars. 

Definitely sounds like movement in the transmission so there should be a brace type mount to limit the movement between the body and the gearbox

On 8/24/2023 at 11:03 AM, Dejan said:

I was wondering if it'd normal for the gear stick to have a slight movement when it's in 3rd or 4th gear. It moves about 8mm with acceleration and deceleration. 

I replaced 2 engine mounts, the third one (under the battery) seemed ok so I decided not to replace. 

The gear stick still have a bit of movement. I'm wondering if I should replace the third engine mount and if it would make any improvements or this is normal thing with nissan cars. 

As far as i know this gear shift movement is "common" at all QQs. Mine is also moving the way you descride. I asked and told me, its common issue and not a problem.