Torsen V8 rear diff swap! How-to.

[ranz]

It is possible to use both original flanges and not change any of the O-rings, you just have to take off 5mm from the torsen differential, original diffs toothed point (where is the locking system) is 20 mm, torsen differential is at the same point non toothed and 25mm, that 5mm stops the S2 flange to go in as far as it supposed to go. Another thing is that you need longer flange bolts (about 15mm longer) because V8 flanges are longer than the S2 flanges.

One thing more... you have to add 5+mm of material inside the diff (depends how much you took of from torsen diff), top of the left flange.
It is because, when you use S2 original flange, it is shorter and when you tighten the bolt without any extra material, it will lock the diff.
Because I had one broken V8 flange, I took from it 6mm and added it inside the diff, the car runs wihout any problems

[Pembo]

Just doing this swap and trying to lift the open diff out of the CQ diff casing and it won't. Crown wheel seems to be catching on the opening. Anyone come across this?

[Error404]

nope, mine just came right out. Is it a very early one with the intergral rear mount maybe they are different?

[Pembo]

nope, mine just came right out. Is it a very early one with the intergral rear mount maybe they are different?

No it has 'bolt on wing mounts'. Great diff too with no backlash. I'll keep trying as nothing lost as I've got this far with it. Might try to unbolt the crown wheel and remove it separatly to the whole diff.
I do have another spare diff so I'll take that apart too and see how far I get.

[|CL|NIKI]

Hi,
From what car we need to take off this V8 rear diff?
Thanks

[Error404]

Audi V8 88-93

you can use both the auto or rare manual ones

[|CL|NIKI]

That's mean Audi 200 4.2l V8? or not?

[Error404]

no. just the V8

[Henkjan]

http://en.wikipedia.org/wiki/Audi_V8

[|CL|NIKI]

Oh - now I see..... Ok - thanks.

[A1QSHIP]

O.K, I have a cq 7a rear diff with the smaller inner cv joints & axle flanges. I have a v8 torsen diff & I want to swap the torsen in to the cq diff. I have the rear axles from an ABY s2 with the larger inner rear cv joints. I know that I need to use the left V8 flange to fit this to an s2 diff that comes with the larger output flanges fitted on both sides. I want to use the larger rear diff flanges from the V8 diff on BOTH the left & right sides of the cq diff with torsen fitted. Will this work or do I need the right side output flange from a s2 rear diff?
TIA, Chris

[Error404]

That's what I did on my cq. Use s2 rear shafts and both v8 output flanges, bolts straight up

[A1QSHIP]

That's what I did on my cq. Use s2 rear shafts and both v8 output flanges, bolts straight up

Cheers! Thank You.

[|CL|NIKI]

I'm looking to buy 1 V8 diff - if somebody got it for selling pls PM me.

[porkkis]

I swapped a V8 torsen unit to my B3 80 quattro running the small 90mm rear flanges. No reasonably priced S2 coupe rear driveshafts could be found so I got another RH side small flange and used them on both sides. They need 9,3mm tall 25mm diam spacer bushes with center hole for the M8 bolt to extend the flange shaft length inside the torsen unit. That's all.

LH side V8 (or urS6) seal is of course needed too.

Here you can see the difference in flange length. All non torsen rear flanges (90mm, 100mm, 108mm) are interchangeable. V8 flanges are unique because of the longer splines. They should be used on both sides when using the 108mm S2 rear shafts.
Take care there's few tenths of play between the torsen unit body and the flange when tightened up.
Also the correct lenghth of the flange center bolts is crucial. Too long will meet the bolt end on the other side and that's not good.