Race Engine Forum UK

GUYS,

NEED HELP WITH PARTS IDENTIFICATION

( As you my quickly notice I am far from being an expert on diffs !!!

I HAVE THREE SETS OF C&P ( ALL ARE FACTORY SETS) :

# 1 SUPPOSEDLY FOR 131 ABARTH (8/43) # 2 SUPPOSEDLY FOR 131 ABARTH (10/43) # 3 SUPPOSEDLY FOR 124 SPIDER (10/41) QUESTION:

The #1 and # 2 ( supposedly for 131 abarth) seem to have different grooves along the back of the shaft. They also differ in length and different diameter for the end screw.

How to interpret this (for different models? Not for abarth ? Which one if for 131 abarth?

How come the shape of the grooves on # 1 and # 3 is exactly the same ?

How come all the pinions are of different length ?

Can anybody provide guidance ?

Miro

The lower one certainly seems to be 124 CSA, it has a much shallower taper between the bearing journals, plus it looks exactly like the one in my 124CSA manual.

The grooves - splines I think you mean - may just be same because the 124 and 131 share the same input hub?

G

Boys
The things are very simple. 124 and 131 Rally shared EXACTLY the same differential. Only change happened was the output shafts of the later 131 were much thicker.
Back to your photoes now. The only abarth ratio is picture #2 10/43.
The pic #1 has wrong type of shaft "teeth " profile . It should be thicker as per photo #2.
The pic #3 has not visible bolt holes on p .It should be as per pic #2.
No doubt that you have only 10/43 Abarth rally ratio.

Achy

Simple, ah?

First thaks a lot for explaining it. You are the only one that knew (or responded) and the post was there for a while. So this is not common knowledge !

Second, the differences between them were too big for all of them to fit 124/131 abarth - thus my question.

Actually I bought the 8/34 (picture 1) from the same guy who sold me the abarth diff, and I thought he knew wht he ws selling . I will contact him for xplenation.

So I understand that :

- 10/43 ( picture 2) is definitly 124/131 abarth
- 8/34 (picture 1) unknown but definidly not 131/124 abarth
- 10/41 (picture 3) not 124/131 abarth (I believe this is regular 124 but not sure which model if they were different. I have a 1980 124 CS0 hope it fits.)

What do you mean by "BOLT HOLES" ?

One more qustion :

Can I safely unscrew this nut ( in red circle ) to see if the shatf has the same teeth ? There is no oil in the diff !

"safely" = not upseting any adjustments in the diff

Thanks gain

Miro

Guys,

One qustion remains : what is behind curtain # 1 (picture 1).

Could it be from Fiat 2300 or Fiat 241 (small truck) which reportedly used "the same" parts.

Miro

OK Maybe not so common but now I think that you have something to walk on.
No it is not safe to unbolt just as simple. You have to mark the nut so you put it on the
same place or check the 124 csa manual for the Ntm you need.
I can tell you right away that you will see the same teeth profile on the shaft.
Now the tricky point : 241, 2300,Dino used the same internals. I believe that
short ratios are from 241 (you need it on trucks) also they short ratios have
old part numbers
- 8/43 n 4273586
- 8/39 n 4163801
- 9/40 n 4207724
- 8/37 n 4157132
- 7/43 n 4273579

From dino you can get 8/39 AND LSD ( I do
not know of 2300 had LSD- 241 did not)

Achy

I was not very clear on my previous reply , Pic 1 is NOT 2300 or 241 as these were identical to rally parts.
And bonus pics (Dino internals 8/39 and LSD)

I just wanted to remove the shaft hub (to see what groovs it has) but not it is pointless and since risky I will no try it .

But more importantly:

Could you possiby , by any chance, be persuaded nicey to part with these Dino internals ?

Miro

Good of you to help here Achilleas!

Nice to see two forum members working together on a very technical issue.

Well done, a good example to all of us.

GC

Guy,

This is the very raison d'être of an elite group like this.

Thanks Guy !
Thanks Achilleas !

Miro

PS : In fact I was so cooperative as to offer taking the budren of having the Dino LSD and diff internals from Achilleas (for a fair price that is) , but so far all he offered was pictures (LOL).

Miro:

"Can I safely unscrew this nut ( in red circle ) to see if the shatf has the same teeth ? There is no oil in the diff !"

Yes you can.

I'll leave you to 'haggle' over trade between you and Achy - but do it offline!

GC

Thanks a lot ,

Miro

(re: off line : will do !)