Technical Car shacking at 85 till 110 km/h

[rgberkhout]

Hi to all, I own a 2007 (140k km) Bravo 1.4 t-jet, last year the driver side support arm is changed due to wear out of the ball joint. In Februari my car started shaking around 85 km/h Usually 4th gear but is also notable in other gears (higher RPN but same shacking). When I loose the throttle it's gone.

Yesterday the car went to the garage and they found out that the rubber in the back was worn-out, they changed it free of charge (for now) as it is warranty.

Today I Aligned the car to it;s proper values and took it for a test drive. At around 85 km/h there is still the shacking especially when I drive upwards although it's far less violent.

There is in the steering rod more then 1 mm of slack on both sides, could that be the cause of shacking and the rubber wearing out or should I look further.

The most possible scenarios for me are:

*slack in stearing rod
*faulty weal bearer
*Faulty disk breaks
*oblique drive shaft
*engine support bearings/rubbers (*edited)



What do you guys think, I do not want to change the support arm again next year..

Furthermore I love my car

 

[glenn2602]

Vibration is usually caused by the wheels being out of balance - they need to be balanced - and/or worn steering joints or bushes.

It's highly unlikely that your brake disks are causing the problem. It's unlikely that a wheel bearing or drive shaft is causing the problem. Wheel bearings and drive shafts, when worn, tend to make a humming/grating noise; sometimes a 'knock' when the car is turning.

 

[1.8Stilo]

Sounds like drive shaft, it's common on the Tjet's ours definitely shaked, it didn't make any noises!

Ours started around 45-50mph, we did all the usual things like having wheels checked for flat spots, re balanced, wheels aligned and it made no difference.

Have a search as there is a few good threads about it

 

[Thomaz27]

I changed almost the whole suspension front and back. Nothing helped to get rid of the vibrations around 70km/h -100km/h. Finally I found that the inner drive shaft cup had dents in it because of grease bean leaking out of the rubber bot. I changed the cup and rubber bot and the chaking disappeared. Check if there is a grease leak on the drive shafts.