How not to do a deal.

[Thotos]

I would check you don't have a series 3 axle from a super fitted to your car. As noted above they are slightly different.

I'd second that. I see no reason to have different axles for LHD and RHD cars and I never thought there was such a difference. The diffs on the 131 Sport are notoriously weak (I've wrecked a few of them  ) so it's likely that many 131 Sports have had a differential or axle change in their life.

[Sev131]

Need pictures of your axle. Later type are longer. I would keep hold of the lsd.    when i get back, i will post some pics.

[longhamrob]

I would not know how to tell the difference between a series 2 or 3 axle without dismantling and measuring it and that would be to me a massive job probably with a very likely negative result.
 When my axles were dismantled, three of them over the last year, they all looked identical and crucially two had the correct diff ratios 39/10 and one was 41/10 which is my spare axle. As far as i can see from data sheets the series 3 axles, regardless of which model, did not have these ratios. I would think it unlikely that my car had a diff swap then someone managed to get an original diff back in.
Bearing in mind the Bacci diff had different splines and a different driveshaft width it also was not going to sit central in its casing i assume the diff casing would be visibly different from the outside.
If anyone has external pics of a series 3 axle (the centre part) i would be able to compare.
Thankyou to everyone who contributed to this topic.

[kev131]

Here are the best pictures that I have from my S3 Super 2000. Hope they help....

[TOAD]

I thought the only difference was,  one is a little wider which can be measured from the outside.

[longhamrob]

Thank you kevin for getting those pics on line so quickly.  That is a very tidy 131 underside!
 To be honest i cannot visually tell any difference. However it may be worth noting some time ago when i had the 1st axle dismantled i bought a new 131 axle cover gasket from a foreign, probably italian, ebay site. It cost only a few quid but when i gave it to the axle fitter this did not fit either. I still have that gasket and this could well fit a series 3 or a european 131 racing but it definetly did not fit mine.
I note on Kevins pics there appears to be some numbers stamped into the main body casing.
I shall look at mine later and report what number sequence i have.
   Thanks to all concerned....

[Sev131]

The only difference is the casing is a little wider which can be measured from the outside and the bevel gear splines where the halfshaft end splines meet.

S2 Sport etc diff plate cover has an indentation in it, where as the S3 is all sought of oval.

Have some pictures, will load up tonight.

[longhamrob]

I cannot make out hardly any of the numbers clearly but from looking at both my identical 131r axles these numbers are definetly different so further examination is meaningless.
I hope sev's pics may give more information....

[Sev131]

I had both diffs out today and both will fit either series 2/3 casings. It's the halfshaft fitment that you would have a problem. On the series 3 diff, the splines are a lot bigger and the shaft is longer. If the diff does not fit at all then I would say it is wrong. Send it back for an exchange. They must of sent it wrong.