Dangerous difference.

[IanR]

Lately the n/s lower ball joint on my M49 has been getting noisy. The replacement arrived today so I set about changing it. The old one was a bitch to get out of the pinch clamp (no surprise there) but the new one went in surprisingly easily. Too easily to be true,  Citroen jobs never go like this, thought I, there's bound to be a a catch here. Yes, there was.  

Turns out there are two sizes of pin, 18mm and 16mm, and I'd been given the wrong one.

I was lucky to spot this, otherwise I'd likely have had a suspension collapse on the road, as the pin was not properly secured at all in spite of the clamp being tight.

Don't like pinch bolts anyway, but making two versions with slightly different pin diameters of a safety-critical component that are hard to tell apart.. Man, that's braindead design.

Anyway, heads-up on this one, that's if it hasn't been posted already.

[jj9]

Yes,  I've always thought that was a very bad design idea having the two so close in size that they can be mistaken as the same, it does make you wonder who gave that the go ahead doesn't it  


.

[geoff]

Probably a case of the manufacturer standardising components accross model ranges for big savings.

I don't think it is a bad design more a case of an inexperience person failing to notice not only an obvious visual size difference but also not knowing that the ball joint should be tight in the receiver and not like a c*ck in a sock. The worst thing is the trying to tighten up the split clamp to an undersize pin.

Aplogies for being hard on you but such things are beyond being schoolboy errors and border on the positively dangerous.

[jamesg]

Oh yes, has exactly the same thing on the 306 a while ago! Fitted the 16mm ball joints when should have use 18mm. Opening the pinch clamp up again was a pain as it was squeezed right up. Grrr.

[ffrenchie]

The pinch bolt should also locate in a groove on the stem of the joint to stop it pulling out, it doesn't just rely on the clamping force.

[jamesg]

The pinch bolt should also locate in a groove on the stem of the joint to stop it pulling out, it doesn't just rely on the clamping force.

Indeed, that was one of the factors that made me realise it was the wrong part. Should have compared the new to the old properly. My bad, but not something I'd have expected.

[geoff]

Oh yes, has exactly the same thing on the 306 a while ago! Fitted the 16mm ball joints when should have use 18mm. Opening the pinch clamp up again was a pain as it was squeezed right up. Grrr.

Well having chastised IanR in a previous post :

( such things are beyond being schoolboy errors and border on the positively dangerous )

I'm amazed you actually made this admission I'd have kept my keyboard quiet out of embarrassment ...

Note to self - must improve my shaming technique !

[jj9]

Well having chastised IanR in a previous post :

( such things are beyond being schoolboy errors and border on the positively dangerous )

I'm amazed you actually made this admission I'd have kept my keyboard quiet out of embarrassment ...

Note to self - must improve my shaming technique !

Try.... Note to self - must stop being a smart arse! 



.

[IanR]

Geoff, I posted this thread because I saw a possibility here for an inexperienced home mechanic -or even a rushed professional- to have a serious incident with this. I didn't have to come here and post this, in fact I gain nothing from doing so as I have already identified and solved the problem. If you think I shouldn't post a warning about a part identification oversight which could result in a wheel-off situation if not spotted, then you are indeed a sick person. Or a troll. (Is there any difference there...)  

I have been maintaining my own vehicles since the original Mini Cooper was the trendiest thing on the streets. How long have you been in this trade? If, you are in the trade at all, that is.

[geoff]

For general interest :

I rebuilt my first 2 stroke motorcycle engine 46 yrs ago - Villiers 2T
My first 4 stroke motorcycle engine 42 years ago - Triumph Tiger 100
My first motorcycle gearbox rebuild was on a BSA A10 44 yrs ago
I rebuilt my first car engine 38 yrs ago - Morris 8 Tourer
My first car gearbox rebuild was on a Rover 60 nearly 35 yrs ago.
I've done lots of other makes since then as well and none have blown up.

I've only ever twice put a car in a garage for any work to be done, once for key coding and once for some welding when my welder broke down.

I've totally rebuilt several vehicles over the years and these include Berkeley SE492, Land Rover Series 2 and Triumph Dolomite, all work done by myself. I can even lead load and spray cellulose to a standard where I've had vehicles winning best in show.

I've also spent almost all of my working life in Mechanical Engineering.

I can appreciate you wanting to advise others of pitfalls nothing wrong in that as anyone can make a mistake but lets be honest here it is a schoolboy error.

Oh yes the trade - I'm not in any trade now by the way I'm retired.