Corolla Knocking when Slow over bumps

[jono987]

Hi everyone,

At the moment when im driving slow in my corolla over bumps there is a nocking which seems to come up through my steering wheel.
Turning dosent seem to effect it happening or not and when driving over a certain speed it is ok.

Steering wheel also vibrates over 80mph not sure if this is related?

I asked them to look at it in the garage when i had it MOT'd and Serviced but they said everything looked ok and there were no problems.

Thanks for any help!

[oldcodger]

If the mot did not detect any joint play it could be brake pad rattle.

If you go over a bump and you hear the noise, do it again but this time brake slightly, does the noise stop, if so brake pad rattle; given everything else is ok with all the brakes.

Also you could have some wear in the antiroll bar rubber bushes or drop links, they are said to be common causes of such  knocks when a little wear sets in, though no first had experience of it and the mot might not pick such early wear up.

Vibration at over 80 a bit more unusual, if it was wheel balance it normally comes in at at 60 upwards , sometimes settling down above 80; never discount the balance of the rear wheels.

What about when you brake at high speed, does it improve or worsen the vibration.

Do you do your own servicing, is that garage who did your mot one use use regularly and trust.

When did the vibration and knocking begin, any work done in those areas recently .

[jono987]

Hey Codger, thanks for the detailed reply.

It recently had some work done in the garage. Before it nocked really really bad when braking heavy. The garage found that the discs were badly warped. They changed these and the pads and it no longer happens under braking. 

Garage is one i and Dad has used for  around 30+ years, always been good with us before. The vibration at high speed i believe started after i curbed the car quite badly. After curbing it, i took it straight to the garage who looked over it for a good while and said they couldnt find anything obviously wrong with it. 

I found an article where someone has had a similar issue, apparently theres a bolt in the steering rack that comes loose? Apparently Toyota replaced the full rack on peoples Corollas not realising it wasnt such a major issue.

My Girlfriends dad is a mechanical engineer who fixes cars in his spare time. I am going to take it to him tomorrow and ask him to give it a good look. 

Car is coming up to 100k miles now and has never let me down in any respect. Hopefully i can find the cause the the little niggles as dont mind spending some money on here to keep her running nicely.

[oldcodger]

Hi,

Likewise, mine has just passed 100k without any real problems, though everyone keeps telling  me to get a new car .... but it goes so well ....

Did you replace the curbed alloy with your spare wheel to see if that highlights the fault ?

Often a curbing will damage the tyre or wheel , though perhaps not visibly, and  also knock the tracking out; typical symptoms uneven tyre wear and steering pulling.

Not sure about loose steering bolt  ?  - any links /details ?

[jono987]

This is the article i found on this site:

 

Never replaced the curbed alloy. I actually went sideways onto a roundabout  So it would be both front and rear left wheels lol. 

[oldcodger]

Seems I did ask the question ,Which Bolt, though no clear response, cannot see toyota replacing the whole rack just for the two rubber support bushes/bolts as that post implies.

Even if you did bang both f and r wheels, worth trying your spare on each in turn, it might quickly isolate the problem  and / or  place both  'good' offside wheels  on the fronts and then the rears to  see if that makes any difference.

Though as I understand it, there is no adjustment to the rear axle/suspension, so if you still have problems, then it might be worth having a full front and rear alignment check.