ALFAGTV6.COM

Hi there,

I have been searching through the old site posts and still cant seem to find the exact answer i am after.

I have a 86 GTV6, larger cams, K&N etc, looking at future performance mods, supercharger or turbos.

I was going to rebuild my Transaxle as it has almost done 300,000kms and is getting a bit tired.
I was wanting to put in a 25% LSD out of a Alfa 75, (has not been sourced yet).
Is there any way of fitting it to the standard GTV6 gearbox?

Reason why is that i really like the gear ratios etc, good balance between top speed and down low, and also wanted to keep the twinplate clutch, and didnt want to be messing around with the speedo and gear linkages.

Is it possible? What Alfa 75 should i be trying to find.

Otherwise what other transaxles would be most suitable/easy to swap.

If you need further details like Chassis number or other, please ask.

Thank you,
Karl

ok.

for the lsd. you can find it on twin spark, 1.8 turbo gearbox.
in the 1.6L and 1.8L na and in the 2.4Ldiesel there is not.

the final ratio is the 4.1/1 in the ts box(like the gtv6; 10/41), in the turbo is longer (11/43).


the best for you.
keep the final ratio of the gtv6, then you kept the secondary shaft with the speed sensor original.

and fit the ts or turbo speed sprockets, stagging are beter.
the 1st is far longer, the 2nd id longer, and the 3th is a bit more long than the gtv6 gear ratios, for the 4th and 5ft is the same ratios.

the gtv6 gears ratios.
1-3.5
2-1.956
3-1.258
4-0.946
5-0.78
ts/turbo gears ratios:
1-2.875
2-1.72
3-1.226
4-0.946
5-0.78

after you have to set 3 vital clearances.
the differencial bearings axial play
the pinion to crownwheel play
the pinion to crown wheel distance.

say us more when it begins.

Thanks,

So if i just want to keep everything exactly the same as it is now, but with a LSD diff,
i need to find one out of a Alfa 75 Twin Spark and it will be a straight swap.

What year 75 should i be looking for?
198???

Thanks Again

Alfa GTV6 NZ wrote:Thanks,

So if i just want to keep everything exactly the same as it is now, but with a LSD diff,
i need to find one out of a Alfa 75 Twin Spark and it will be a straight swap.

What year 75 should i be looking for?
198???

Thanks Again

hello
first before all; what year is your gtv6 ?

yes but no.if you put a ts gearbox on your gtv6 everything is the same, instead of 1st 2nd 3trd gears ratios ....-> better.

any year of 75 twin spark gearbox will be ok, they are all the same during years.

but ! depending of the year of your gtv6 there is a difference in the shifting linkage.
something like; if your gtv6 is 86 or 87' model is ok is the same shift linkage.
if its not....dont be afraid, just a little swapping of the shifting parts; you dont need any special tool, or masterskills, just a few of wrenches, sockets metric and sealing paste for the casings(loctite 518)

however if you kept the secondary shaft of the ts gear box, you dont need to have vital clearance reajustments but you will loose the speedometer because the sensor have nothing to look.
also the forward gear box casing is different for the speedo sensor attachement.

if you want to put just the lsd in the rear of you gtv6 box, you will need to set 2 vital clearances, so need tools.



looks like 2 solutions for you.

swap the gtv6 gearbox for a ts one, and depending of the year of your gtv6 this will cause you an extra job of one hour, and you will lose the speedometer.

fit in the gtv6 gearbox the lsd in replacement of non lsd diff, fit all the sprockets of the ts gearbox, and set all the vital clearances.


when im speaking of swapping sprockets, keep in mind that:
-for primary shaft (clutch); sprockets cant be dismantled of the shaft so its complet gtv6 or ts shaft(i dont give detail, read the follow to know what about i'm speaking).
-for secondary shaft(speedo and lsd crownwheel) sprockets can be dismantled so you can keep the gtv6 shaft(and speedo) and fit all the ts gears.

Sorry for stealing the thread (what can I say, I am new here ), but i have a question to Tectoteam.

By alternativ 2 (sawping sprockets) do you mean that one can open the difrential cover in the back/side of the gearbox, and replace the complete GTV 2,5 crown wheel with the complete crown wheel ( including LSD) from the TS? without needing to change/ replace the pinion axle/wheel? In my low theoretical knowledge, this should be possible since both GTV 2,5 and TS have the same ratio on the final drive... can you please comment this?

do you mean that one can open the difrential cover in the back/side of the gearbox, and replace the complete GTV 2,5 crown wheel with the complete crown wheel ( including LSD) from the TS?

I would NOT do this. They are most certainly a matched pair.

I agree with Micke.

Also, the flange that the crown wheel rests on is not the same height and the pinion will bottom out in the crown wheel while there is still a ~2mm gap between the box body and side... (if you try to put the LSD only in the 2.5 box)

Swap the whole box, better gearing in the speed gears and LSD. The output flanges might differ though, never done the switch myself so I can't tell.

I swapped in my Alfetta 4 door first a 75 2.0 box, which I later exchanged for a TS unit. I recall it was pretty straightforward. Main issues speedo and gear lever.

important thing when playing with LSD box or diff swap is to change friction plates or add 2 more for 50%lock ... mine TS box have 200k km and there is almost zero lsd

It's also important to know that adding friction plates might be totally unnecessary depending on what you want.

Doesn't the V6 have those extra driveshaft spacer thingys? If they do they also have different driveshaft bolts, right?

the twinspark runs the same driveshaft and spacers as the normal 2.0l's. the v6 has different driveshafts and run no spacers between the disc and the shaft. the allen cap bolts are also longer and if memory serves me right 8mm size allen key. basically try and stick with the 2.5 or 3.0 stuff. also someone may have already mentioned this but ill say it anyway, remember that the clutch slave cylinder is in a different place all together on the twinspark box. may involve modifying your line. when i did this conversion a few years back i used the 75 3.0l complete box with a 4.1 lsd in place of the 3.5.

patzo_3l

You got it backwards, the 75 style boxes (TS) does not have any spacer or similar between the drive shaft and disks and they need the longer bolts. They are indeed 8mm allen.

I use the old 2.0 driveshafts with my TS box. Without the spacers they fit 100%.

Micke wrote:

do you mean that one can open the difrential cover in the back/side of the gearbox, and replace the complete GTV 2,5 crown wheel with the complete crown wheel ( including LSD) from the TS?

I would NOT do this. They are most certainly a matched pair.

i said same.

keep same couple of secondaryshaft/crown wheel.
changing nonlsd by lsd, is possible only, but need to set pinion/crownwheel clearance and bearing 'slipering'

yeah, but it's not something you would do with the GB on the car.