Violent Shaking

[terryhaakman]

Everytime I take the car past 60 km\h the rear end starts to shake, and I mean violently shake! As soon as she comes down below 60, she smoothes right out.

Any ideas?

 

[malcolm]

Hi, welcome to the forum. It'll be air inside the rear dampers. If you jack the wheel off the ground you'll find there is maybe 30mm of travel that doesn't have any damping.

I've had the same problem on a new pair of dampers after driving quickly down a rough road. The dampers are horizontal, so if any air does get in it can't bleed out again.

The best solution is to fit gas pressurised dampers at the rear. Delphi DeCarbon were fitted to a lot of Renault 4s originally by Renault. If you rarely drive on rough roads then ordinary dampers should be OK, or you might improve your dampers by removing them from the car and compress and extend them a few times in a vertical position to bleed the air.

 

[terryhaakman]

Is there any chance that it could be related to tire pressure or wheel balancing?

 

[malcolm]

You could always try swapping the rear wheels with the front ones to see if the problem moves to the front of the car.

The wheels have a resonance at about 60mph caused by out of balance - Might also be a lump of mud inside the wheel or out of round tyres.. The dampers control that resonance, so if it's very bad the dampers probably need to be replaced. It's a common problem. See http://www.renault4.co.uk/tech-dampers.htm

 

[terryhaakman]

I'll have a gander at the dampers - thanks for the advice!

 

[angel]

I bet wheel balance, and as Malcolm said, mud on the inside of the wheel.
I have always mounted bent, unbalanced etc wheels on the rear and never had any problems with vibration (I admit that my dampers were always above average). So I suspect it is something more serious...

 

[terryhaakman]

Turns out that is was the rear, outer suspension mountings. The driver side mount was rusted all to crap. It's sitting a a bodt shop now waiting to be jimmied back together. The guy has 2 other R4's on his lot which gives me the impression that he knows exactly what to look for and how to fix it up. He's going to check the passenger side as well and do some minor work on the front end.

If his work holds up and I don't have any other problems by mid summer I just might have to get all the rust patches taken car of followed by a fresh coat of paint!

I'm telling you, it is so frustrating to deal with the mechanic types in this region. Everyone I go to tells me that I'm wasting my money, I should never have bought an R4, I should just through it away and buy a Golf. Well, I bought a Golf for my wife and I'm keeping the R4 DAM IT!

 

[angel]

A friend of mine had a Golf, then got a R4 and now he is thinking about selling the Golf...

 

[french four]

I sold my mk5 golf and kept my r4

 

[Melc]

Me too

I got a Golf for my wife, good trade hey?
But I still kept the R4. Maybe I can get a 4 for the children.


" An R4 will get you through times of no money, a lot better than money will get you through times of no R4"

Louis Renault (posthumously)