My car feels unstable in a straight line at speeds of 60mph -80mph. It’s had 4 new tyres, new rear shocks, new front bottom arms and drop links and a 4 wheel alignment done and still when you drive in a straight line on the motorway and go to overtake the back end feels wallowy and on long left hand corners the traction control light flickers randomly. Does anyone know what it could possibly be and what could cure the handling problem? When you just gently turn the steering wheel at speed the back end feels like it’s all over the place before it nips. I know it can’t be anything major but I can’t for the life of me figure out what’s causing it. Please help!!!

Very likely one or more rubber bushes in the rear suspension is soft or disintegrating. It would be worth renewing all of them before getting the rear tracking checked.

Thank you. I’ll get it back on the lift and replace them. 👍🏼 

What make shock absorbers did you fit Dan?
Perhaps rather than wading in and renewing any bushes, it would probably be well worth giving them a couple of coats of inspection before doing anything else. 
Regards,

Gareth. 

Monroe. I thought this would cure the problem as the old ones were stock from new but it didn’t cure it at all. The same flirty back end at speed 🤷🏼‍♂️ 

Should be alright with those then Dan. 
Always difficult to try to help from afar with this sort of thing.

Clutching at straws here, and no doubt you have checked:-

Bottom suspension pans at rear OK? Very prone to rust and weakening. Quite a lot of links on the back, and all with rubber bushes.

Was rear wheel camber checked and adjusted via eccentric bolt? 
Daft question, but tyre pressures set to book and reputable tyre brands for new tyres? 
Your symptoms sound like the tail is wagging the dog, as we used to say.

Regards,

Gareth. 

 

It’s like when you go round a corner the car takes a while to settle before finally gripping. The not knowing what it is is driving me insane as normally I can figure out pretty much any problem a car has. The rear control arms are rust free but I’ll have to get it on the ramp and check the rubber bushes as if they’re perished I would imagine it’s causing this issue. I’ll replace both bottom control arms if that’s the case and put new springs in whilst I’m at it. If that’s doesn’t cure the problem I’ll have to go back to scratching my head 🤷🏼‍♂️ 

You said you had a 4 wheel alignment done. Did that include a check and adjust of the rear wheel camber? 

Sorry I said four wheel alignment but I meant they just tracked the front wheels up as they were well out. They used a laser to set them shining a laser on plates on the back wheels. They never checked the rear camber. Maybe that’s what’s causing it? I wonder if the back wheels are pointing inwards slightly. It feels like they are the way it’s handling 

The rear suspension alignment certainly needs to be checked, but that would be pointless until any slop is removed from the links.