G.Knight
New member
- Joined
- Oct 11, 2021
- Messages
- 2
- Reaction score
- 0
- Points
- 1
- Genesis Model Year
- 2015
- Genesis Model Type
- Genesis G80
Greetings.
I'm a new member here
Hope i can be up to the task on giving as much helpful information as possible considering my issue.
Ok let's start first about my history with my G80 which was bought used from the dealership.
First:
My car was bought used with too many issues which wasn't covered by the dealership before i bought it, but the good thing is that it was still under warranty.
The car driven distance when bought was about 25.000+ miles or specifically about 55.000+ Kilometres.
Second:
After i bought it - my first major mistake is that i didn't take my time to test the car before buying it because i was in a hurry after i sold my previous car.
After driving it for sometime - i noticed a strange funny noise behind me.
It sounded like this:
Waowaowaowaowao.
After i asked about it - i was told that it could be a pull or ball bearing issue.
I took it to the factory then they fixed it under warranty.
Later on - i noticed the transmission kicking me when downshifting at about 50MPH / 80KPH.
I took it to the dealership then they also replaced my transmission under warranty.
The problem seems to be solved but later on it went back again.
When i asked & debated with the mechanic - he told me that it is a normal thing on all V8 Genesis G80 5.0 models.
To be honest my mind was boggled from his statement.
I took it to an outside garage ( not dealership ) then when they checked the transmission shifting behaviour under parking mode - the mechanic responded with this:
Your back axle needs to be checked or fixed.
I think he is referring to a certain part which is connected to the transmission so pardon me if i got the part name wrong.
Until now i didn't attempted to fix it yet ( i think because i didn't gave myself the time to check on it )
My cousin told me that it could be related to the transmission seats ( It's a local term where i live so pardon me if i wasn't clear on my term ) which i think is something which works like an isolator for the transmission vibration.
Third:
Now i'm having another issue which is the main issue as written on the thread title.
The car shakes at speeds over 60MPH / 100KPH at 7th & 8th gear.
Me and my cousin had tried to diagnose the problem by giving the car a certain tests on the road.
We tried the following:
1- Switched off Eco mode into Normal mode.
2- Tried to use automatic & manual shifting modes.
3- Checked all the wheels.
4- Checked all tires pressures.
5- Tested the braking behaviour.
6- Tried the 7th & 8th gear driving at over 60MPH / 100KPH with Drive mode under stable acceleration speed & deceleration with also shifting to Neutral while the speed was at 60MPH / 100KPH.
Finally:
After all of the tests above we've reached the conclusion that the issue isn't related to the wheels - tires or brakes.
It could be a transmission issue.
We believe it could be related to the transmission seats or it could be the engine isolator part ( Harmonic balancer correct ? )
The frequency of the shaking is stable even if we increased the speed ( the shaking doesn't become faster in frequency but based on my experience it is a stable shaking but can gets rougher on higher speeds )
Is it the correct assumptions ?
Thanks in advance.
I'm a new member here

Hope i can be up to the task on giving as much helpful information as possible considering my issue.
Ok let's start first about my history with my G80 which was bought used from the dealership.
First:
My car was bought used with too many issues which wasn't covered by the dealership before i bought it, but the good thing is that it was still under warranty.
The car driven distance when bought was about 25.000+ miles or specifically about 55.000+ Kilometres.
Second:
After i bought it - my first major mistake is that i didn't take my time to test the car before buying it because i was in a hurry after i sold my previous car.
After driving it for sometime - i noticed a strange funny noise behind me.
It sounded like this:
Waowaowaowaowao.
After i asked about it - i was told that it could be a pull or ball bearing issue.
I took it to the factory then they fixed it under warranty.
Later on - i noticed the transmission kicking me when downshifting at about 50MPH / 80KPH.
I took it to the dealership then they also replaced my transmission under warranty.
The problem seems to be solved but later on it went back again.
When i asked & debated with the mechanic - he told me that it is a normal thing on all V8 Genesis G80 5.0 models.
To be honest my mind was boggled from his statement.
I took it to an outside garage ( not dealership ) then when they checked the transmission shifting behaviour under parking mode - the mechanic responded with this:
Your back axle needs to be checked or fixed.
I think he is referring to a certain part which is connected to the transmission so pardon me if i got the part name wrong.
Until now i didn't attempted to fix it yet ( i think because i didn't gave myself the time to check on it )
My cousin told me that it could be related to the transmission seats ( It's a local term where i live so pardon me if i wasn't clear on my term ) which i think is something which works like an isolator for the transmission vibration.
Third:
Now i'm having another issue which is the main issue as written on the thread title.
The car shakes at speeds over 60MPH / 100KPH at 7th & 8th gear.
Me and my cousin had tried to diagnose the problem by giving the car a certain tests on the road.
We tried the following:
1- Switched off Eco mode into Normal mode.
2- Tried to use automatic & manual shifting modes.
3- Checked all the wheels.
4- Checked all tires pressures.
5- Tested the braking behaviour.
6- Tried the 7th & 8th gear driving at over 60MPH / 100KPH with Drive mode under stable acceleration speed & deceleration with also shifting to Neutral while the speed was at 60MPH / 100KPH.
Finally:
After all of the tests above we've reached the conclusion that the issue isn't related to the wheels - tires or brakes.
It could be a transmission issue.
We believe it could be related to the transmission seats or it could be the engine isolator part ( Harmonic balancer correct ? )
The frequency of the shaking is stable even if we increased the speed ( the shaking doesn't become faster in frequency but based on my experience it is a stable shaking but can gets rougher on higher speeds )
Is it the correct assumptions ?
Thanks in advance.