golf 1, jerking when reaching high speed or selected 5th gear

[cliffmotsamai]

Good day guys

my golf 1, is having issues when driving above 90km/h especially when engaged 5th gear, along the way when speed increase it keeps jerking then i have to lower the gear down for a while then shift back to 5th gear,

[Neuk]

Have you checked timing, fuel supply, spark?

[cliffmotsamai]

Hi yes i have checked all that, when that happens its like a knock on the right hand side of the car, as if there is a problem with a drive shaft ,i even tried to change Inner CV thinking its worn out