odd clunk when reversing on lock CLK

[moonloops]

Anyone suggest what this could be?

Basically when I reverse with full or nearly full lock applied I get a double knock. Is a strange clunk/crunch sound back to back. Definitely comes from the front of the car. Only other way to describe is if you say ran over a pebble. You can feel movement through steering.

Other than that, no other strange noises or behaviour. Brakes and accelerates straight as a die.. ?

Thanks in advance for suggestions.

 

[Howard]

Mine does this when the a) tyres are nearly worn out and b) when it starts getting cold , when you are reversing slowly round a 90 degree corner.

Started doing it the other day ( in the last coldish snap ) , my fronts were nearly on the stops , so had two new tyres put on , and all is good.

Does it feel like the front 'skips' like on a patch of gravel ?

 

[moonloops]

Mine does this when the a) tyres are nearly worn out and b) when it starts getting cold , when you are reversing slowly round a 90 degree corner.

Started doing it the other day ( in the last coldish snap ) , my fronts were nearly on the stops , so had two new tyres put on , and all is good.

Does it feel like the front 'skips' like on a patch of gravel ?

Fairly new Michelins on mine .

But yes skipping on patch of gravel is exactly what is feels like. Only does it the once per manoeuvre.

 

[Howard]

Sounds the same as mine .

Are the tyre pressures ok ?

If it's any consolation , my old w124 used to do it too.

 

[moonloops]

Sounds the same as mine .

Are the tyre pressures ok ?

If it's any consolation , my old w124 used to do it too.

I'll check pressures and maybe just get the local indy to give it the once over. It's only recently starting doing this so it's not a "feature" of the car as such..

thanks

 

[Howard]

Been having a look and there are a few threads on it , some 5 years old , all different cars too...

http://www.mbclub.co.uk/forums/wheels-tyres/12206-suspension-steering-issue-needs-diagnosing.html

http://www.mbclub.co.uk/forums/wheels-tyres/13304-wide-wheel-tyre-steering-slide-query.html

 

[Mavster]

has your car ever had replica wheels on it?

 

[moonloops]

has your car ever had replica wheels on it?

Nope standard merc 17" from new. I've got it booked in to an indy to have a look at now.

 

[DITTRICH]

"skipping on gravel"?
Happens at low parking speed cornering on full lock.
Tire pressure on the front wheels can influence this.
Rounded outer shoulders on part worn front tires can influence this.
In the wet.
Changing camber of the road when turning onto a road across traffic.
I've noticed mostly when going forwards but I have had it happen once in reverse.
New tires will improve matters.
I just live with this.

 

[chris846]

I have this too - It feels like the 'Jud' out of a 'Judder' (that might make sense to somebody!)
I'm certain it's a combination of tyre profile & type, wheel size, steering radius, slow speed, cold tyre, road surface etc. etc that all means that the tye doesn't slip smoothly as it should do in order to follow a curved path - the sidewall just kicks and jumps instead.

 

[Nasco12]

Steering damper?

 

[moonloops]

It's now double "judding"

 

[moonloops]

OK the problem in my case was that the forward thrust arm ball joint covers were AWOL and therefore crud had got into ball joints.

 

[moonloops]

Put new winter tyres on and as Barry Scott would say - "bang it's gone"

A combination of the worn ball joints and another bush I had to replace two months ago meant the edges of the michelin's had worn "funny" like. Now that the suspension is sorted, aligned and new tyres put on - job done.

 

[lordlee]

Mine does this when the a) tyres are nearly worn out and b) when it starts getting cold , when you are reversing slowly round a 90 degree corner.

Started doing it the other day ( in the last coldish snap ) , my fronts were nearly on the stops , so had two new tyres put on , and all is good.

Does it feel like the front 'skips' like on a patch of gravel ?

This is exactly what mine has been doing for the last couple of days. Wish I had read this first as I am pretty sure that the problem has arisen from me swapping my alloys over for refubishment as the front left tyre is quite low on the inside. I spent a good hour with the front jacked up yesterday checking all the bushes. Everything appears fine which is good as its MOT is this week. Going to put some different front alloys on that have far more tread and see if that eases things slightly.

It seems to do its thing when the steering is being straightened from full lock. I was convinced it was a dodgy bush but tyres sound like a fair shout. I have it booked in for a pre MOT inspection on Wednesday so if I find anything out thats useful I will report back.

 

[andy27168]

Hi,
I never saw this thread originally, i have had the exactly the same issues with both my 202's (208 and 202 exactly the same).
In my experience if checking the tyre pressures doesn,t solve it, it will be the camber/castor bushes in the lower wishbone that are knackered (assuming tracking is ok), the prefered method of repair by garages is to replace the entire lower arm rather than the bushes due to the difficulty of removing/replacing the bushes, and time spent doing this could potentially be more expensive than the replacement lower arm.
When I have done my cars i also replace both lower arms at the same time.

 

[lordlee]

That is perhaps not the answer I was looking for!! Its such a shame that the bushes are so hard to get out as they are only about £12 from memory. I was rather hoping not to have to replace the whole lower wishbone!! Is there anyway easy way to tell whether this is the culprit? I have visually inspected every bush and there are no splits, brittle rubber or any sign of wear that I can see.

 

[BlackC55]

Lever the castor bush over and have a very close look at the bush. How wide are your front tyres?