Wheels/Tyres: Front end bounce

[eggie]

hi all

got some new tyres fitted 235 / 40 / 18 continental contisport sp 3's and now i experience front end bounce as if my tyres are bouncing of the road and some vibrations expereinced in acc pedal and steering wheel. Mainly when driving over 40 mph.

Any help appreciated.

Thanks
Eggie

[Paul Wildsmith]

presume you've checked the tyre pressures?

[eggie]

hi

yes the tyre pressure is what stated on fuel flap 38 psi all round on half load and states 41 psi full load but i only use 38 psi.

thanks
Eggie

[prm36]

Check they've been balanced properly

[eggie]

got the balanced checked twice already and fine, the garage did say the front driver alloy buckled abit so i changed it to rear, but problem still there, i also fitted some universal 5mm spacers today, made sure rust all taken off with wire brush on both front hubs and copper greased the hubs before fitting spacers, the reason why i fitted spacers was the front passengers catching wheel arch, so that isnt the real issue.

the real issue is front wheel bouncing if i go over 60 or 70mph quite awful seems the car gonna take off. i also was told by another person on here that changing one shock and strut and not other could be dangerous, is it ? or could that be the cause of my problems as one shock new and one old.?

Any info gladly appreciated

Thanks
Eggie

[davew]

I am not a mechanic by no means but do know general mechanical principles.

A shock is also called a damper, because that is exactly what they do. They are desigend to dampen the bounce on the springs. If you didnt have them and hit a bump it would take forever for it to stop boucing up and down.

By just replacing one damper that means one side of your car will be more efficent at slowing the bounce. Try runining down the road with one spring tied to the bottom of one foot and you will see what I mean.

[stevo48]

Dampers or shock absorbers should ALWAYS be replaced in pairs, if one of your shocck absorbers loses the ability to absorb potholes etc then it usually follows the other shock absorber will also be at the end of its working life as well. Replacing one damper only will upset the balance of the car and cause strange behaviour such as you are experiencing.

[eggie]

hi

thanks for your replies dave and stevo. so basically it could be down to the shocks not being replaced in pairs, i got the pass left shock done not the spring as mechanic said spring ok, so seems i will have to replace the driver side and c what happens.

do i need to buy original volvo shocks as at present i have an oem on left, and also do i need new springs to go with shock ? or old spring ok as mechanic told me.

Thanks
Eggie