C5 X7 ball joint part numbers.

[Lenny]

I've come across two different part numbers for a genuine C5 X7 front upper ball joint.
It looks like they both fit pretty much all models, all years and plenty of Pug 407s too so does anybody know the difference between a 3640.57 and a 3640.74 please?

All aftermarket suppliers list their part as being equivalent to both part numbers and there's no visible difference between the two genuine parts.

[perrye]

I don't think there are any. In SB it does not show price for 3640.57 (only stars ***) so it is not been sold anymore and it is an "old and replaced" number of that part?
And as you wrote every aftermarket manufacturer I checked uses both numbers in their products.
So I'd say it is same part, only different numbers.
EDIT:
looked more:
In mine (Peugeot) it is shown in parts list like this (in new SB):
3640 74
RP 16 357 718 80

But it shows no 3640.57, even in 2013 versions of servicebox. Not in Peugeot 508 or Citroen C5 X7.

[Lenny]

Yep, it's an odd one, thanks for trying to help.
I'm planning a front suspension overhaul and I always prefer to use genuine parts where possible.
I managed to get a 364074 for £8 but I'm struggling to find another for anything less than ten times that but I can get a 364057 for £22.
Cheers,
Lenny.

[Lenny]

Well, if anybody ever needs an answer to the same question then the simple answer is that there is no difference.

I now have two identical ball joints - one came out of a citroen parts bag marked 3640.74 and the other from a bag marked 3640.57.
The actual ball joints are exactly the same in every detail.
They are both have a tiny Lemforder logo on them and several identical numbers on both the rubber cover and the threaded cast base.