Torsen V8 rear diff swap! How-to.

[Error404]

bump to an old thread..... might look at fitting a torsen in my CQ20 at some point, as i will have a "spare" diff in the next few months..... what is the crack with the V8 flange?
I am putting an S2 rear diff into my CQ as the existing one has run low on oil and is now noisy - i know the flanges from the CQ diff need swapping onto the S2 diff - but what is the difference in the flanges?
Will i run into problems with the V8 flange needed when fitting the torsen into the CQ/S2 casing? Any ideas on this?

[Rusty]

This has always been on the wish list... not sure how much I'd get out of the conversion with a mere chipped k24 but the idea of powersliding in the wet around a track has always appealed

[S2central.net]

Well Tom broke one with his monster torque machine... My gut feel tells me that it will be just fine on a chipped S2 (maybe RS2 setup also). I have the guts of a V8 Torsen in storage - just need a suitable donor diff to make the swap as I don't want to dabble with my perfectly healthy S2 rear diff.

Coupled with stiffer rear suspension, this must give the driving dynamics some more rear bias for the fun factor when you want it... It needs to be subtle and controllable for me to use on the roads with ease and safety in mind.

Paul

[Rusty]

Lucky boy

[Error404]

can anyone help with my flange query? what is the dirrerence between the S2 and CQ diff flanges? (as i know i need to swap the CQ flanges onto the S2 diff i am puttig on my CQ for the time being) - by the sound if it the S2 driveshafts will bolt up fine the the required V8 flange - but i'm guessing the CQ driveshafts won't fit the V8 flange if they are not compatible with S2 flanges either.....

[S2central.net]

Difference is the bolt spacing and size of that flange so the inner CV joint connects correctly. Its a straight swap of S2 flange onto a CQ rear diff. I dunno for sure but would expect any flange swapping to be easy enough on your CQ target.

The conversion puts V8 rear diff internals onto the casing so as long as you'll be able to reuse the flanges from your CQ rear diff.

The flanges attach by a single bolt - easy enough - seen it done.

Paul

[Error404]

from reading above though, you need to keep one of the V8 flanges when fitting into an S2 casing, which by my deductions must not fit the CQ driveshaft (becasue it is a straight fit for S2 shaft?)

Second question i suppose is - can i use S2 driveshafts (and diff flanges) in the rear of my CQ to overcome this (potential) problem, or will i also need S2 hubs too?

[mcandmar]

Good point never noticed that. I had a look in the magic album and can see the two complete drive shafts with joints, but no part numbers for just the drive shafts. Inner CV joint is different, but the outer CV joint is listed twice. One version for NM,7A and another for 3B,ABY,NM,7A,AAH,ABC. I assume the difference is the pre 1990 vs 1990 7A models. At a guess if you have a later model 7A it should be the same.

Anybody know if the drive shafts are the same? I have a vague memory of somebody saying they were thicker, and possibly slightly shorter due to the different inner joints.

[WabTheKing]

been working on diffs at uni, does the s2 have the crush washer on the input shaft of the diff? if so was thinking of shimming it instead, dont like the crush washer thing and i like the smell of marking out blue, shame it doesnt come off your hands for a week tho!!!!

[Error404]

Good point never noticed that. I had a look in the magic album and can see the two complete drive shafts with joints, but no part numbers for just the drive shafts. Inner CV joint is different, but the outer CV joint is listed twice. One version for NM,7A and another for 3B,ABY,NM,7A,AAH,ABC. I assume the difference is the pre 1990 vs 1990 7A models. At a guess if you have a later model 7A it should be the same.

Anybody know if the drive shafts are the same? I have a vague memory of somebody saying they were thicker, and possibly slightly shorter due to the different inner joints.

Sods law I have an early 1990 car
Well i'm guessing the hubs will be the same on the CQ20 throughtout production? if so the the two different shaft types must be interchangeable, since the diff flange is also the same (I think).

Question really is whether the CQ hubs will fit with the S2 driveshafts, if so then simply swap the shafts at the same time as the diff and hey presto... pretty sure Azman fitted S2 hubs to his CQ without changing the drive shafts. ergo the splines must fit.... it might just work

[audiman]

V8 diff, forget it IMO. It amkes the car unstable and hard to lay the power down, esp when running big power. It was also renowned for being weak on the V8. Mine chewed itself right up, and i fitted a stock 3b diff in its place. The car was then easier to drive hard.

[Error404]

this would be for a "fettled" CQ mate - not going to be over 200 brake, so weakness not an issue.. just want to make the car a bit less understeer prone and nose biased, some ARB tuning will form part of the package too.
don't think i'll have the same issues with it as you've had

[Error404]

anyone got a clue about the tightening torque for the crown wheel bolts?

[veneto rs2]

I cheked on the garage biblebut could only find:

Heat up the crown to 100° (celsius) the tighten bolts to the torque prescripted....... but no value it's stated....
I've done it but i can't remember what torque we use it...... but we definetely screw up the things tight very tight!

Did you use both flanges from the V8?
because you have to, there's one of the orginals that connects in the opposite gear for just 10/12mm ....... very dangerous.

There're some pictures of my swap on our forum just search for "V8 torsen"

Stefano

[Error404]

Hi Stef,

I haven't done the swap yet, it is a job for the weekend.

I was only planning on using one of the V8 flanges (diff lock side one) - what do you mean the other is very dangerous?