How much movement is too much ?

[del mar]

Morning,

Funny clonking noise from front drivers side on W169 Mercedes A class.

Took the wheel off and used pry bar the lower swing arm has some movement.

Obviously two bushes front and rear, the rear one no noticeable play, the front one 4 - 5mm of movement.

Is that enough movement to create the clonking noise ?

Outer cv joint boot is ripped so will change the entire joint.

Thanks

[Mignon]

del mar said:

Obviously two bushes front and rear, the rear one no noticeable play, the front one 4 - 5mm of movement.

Is that enough movement to create the clonking noise ?

Seriously?

[del mar]

I will take that as a yes then ...

This is the first time I have had a failed wishbone bush before, will order the part.

Del

[dontlookdown]

Any play or movement that you can 'feel' in a suspension joint or bush is too much really. If you can see the movement too then it is definitely shot.

Not always obvious how to unload the joints so you can check them properly tho.

But with 4-5mm movement yours is totally forked yes. You must have had the bass cannon turned up to 11 to mask that one!

[del mar]

dontlookdown said:

Any play or movement that you can 'feel' in a suspension joint or bush is too much really. If you can see the movement too then it is definitely shot.

Not always obvious how to unload the joints so you can check them properly tho.

But with 4-5mm movement yours is totally forked yes. You must have had the bass cannon turned up to 11 to mask that one!

Funny you should say that my 8 year old son has found the "bass" controller on the radio is it does tend to be on 10 !!

[JoeMk1]

del mar said:

Morning,

Funny clonking noise from front drivers side on W169 Mercedes A class.

Took the wheel off and used pry bar the lower swing arm has some movement.

Obviously two bushes front and rear, the rear one no noticeable play, the front one 4 - 5mm of movement.

Is that enough movement to create the clonking noise ?

Outer cv joint boot is ripped so will change the entire joint.

Thanks

4-5mm is not an unreasonable amount of movement with a decent sized pry bar. The front bush on the wishbone will be much softer than the rear one as it is a compliance bush. This means that it allows the wheel to move backwards when it hits a sharp input such as a pothole. (The rear bush is harder so that the wishbone pivots around it looking from above, if you see what I mean) If you had no movement here, the car would be very uncomfortable!

Unless you can feel the bush clonking as you pry it, or is is visibly cracked/split, I doubt it's the source of your knock.

[dontlookdown]

Fair point. Should have added that 'play' means movement over and above what should be there. So if it's one of those big void bushes or squidgy ones that is supposed to move a bit, you have to allow for that.

Can be a bit of a cat and mouse game figuring out which bit is causing the clonk.

[Mignon]

JoeMk1 said:

4-5mm is not an unreasonable amount of movement with a decent sized pry bar. The front bush on the wishbone will be much softer than the rear one as it is a compliance bush. This means that it allows the wheel to move backwards when it hits a sharp input such as a pothole. (The rear bush is harder so that the wishbone pivots around it looking from above, if you see what I mean) If you had no movement here, the car would be very uncomfortable!

Unless you can feel the bush clonking as you pry it, or is is visibly cracked/split, I doubt it's the source of your knock.

The simple answer is test the other side in the same way and see if the play is the same. What any given person does with a certain length pry bar and how much force they use is an unknowable variable.

[del mar]

Fitted new CV joint - noise is gone.

Last CV joint that went gave a clicking on full lock, this one just clonked every now and then.

Thanks

Del