Rear diff coupe and avant/sedan capability

[zafra]

Hello, I am trying to find information, I can not find if it is possible to mount the diff of a coupe in a sedan. In my country, to do a legal swap, you need the donor's engine and gearbox. The car is an 80 2.0 16v quattro and the engine is a 3b with its gearbox, but I don't have a diff, I'm looking for options.

[K Simmonds]

If your car is B3 based then yes a Coupe diff is pretty much a straight fit, depending on drive shaft flange sizes and ratios. If it's a B4 then no chance of fitting a Coupe diff, the back end design is completely different.

A 3B gear-box will work with an S2 diff and a 7A one, not sure about the 10V CQ variants off the top of my head. However a V6 one will not work with your 3B gear-box as their different ratios.

[zafra]

it's a b4 competition... dammit. i have to look for a differential s2 or 7a... would nm work? officially looking for rear differential s2 avant or 7a sedan / avant. I suppose that an s4 is not compatible either, right?

[ak139]

3B should have 01A gearbox AKU or AXL with final ratio 4.11

For B4 sedan you can not use B3 sedan or coupe rear diff.

You need rear diff from B4 sedan/avant with 2.3 i5 or 2.6 v6 diff codes AZE/ACZ which are 4.11
Note. 2.0 8v/16v final ratio is 4.556 and 2.8 v6 has 3.89 CAV
Which are locker diffs.

But you can also use B5 A4 sedan/avant rear diff, which are without lock.
1.8 N/A 4.556
1.8T 3.89
1.9TDI 3.89
V6 engines have both 3.89 DAJ and 4.11 DAK

[zafra]

3B should have 01A gearbox AKU or AXL with final ratio 4.11

For B4 sedan you can not use B3 sedan or coupe rear diff.

You need rear diff from B4 sedan/avant with 2.3 i5 or 2.6 v6 diff codes AZE/ACZ which are 4.11
Note. 2.0 8v/16v final ratio is 4.556 and 2.8 v6 has 3.89 CAV
Which are locker diffs.

But you can also use B5 A4 sedan/avant rear diff, which are without lock.
1.8 N/A 4.556
1.8T 3.89
1.9TDI 3.89
V6 engines have both 3.89 DAJ and 4.11 DAK

Is 2.3 i5 10v 4.11??

[ak139]

Yes, paired with AXM gearbox.

[K Simmonds]

Did they put the 2.3 10 valve or the 7A/NM engines for that matter in any B4 quattro models on the continent? The only quattro B4 Sedan/Avants they offered in the UK were V6 and obviously the S2.

[ak139]

Yes, https://www.ebay-kleinanzeigen.de/s-...quattro-2.3/k0

[K Simmonds]

Cool, I don't think we got those over here, I could be wrong but I've never seen one in the UK.