Alfa 75 gearbox & diff into a 2.0L 1984 GTV

[michaeljc]

I have a GTV with fantastic body but noisy gearbox or diff. I thought that it might be better to instal the LSD transaxle out of a 75. I believe there are a few things to changeover etc to get the 75 drivetrain into the GTV and I'm happy to muck around with that .... but my main question is whether it would be OK to get g/box&diff from a 2.5L 75 rather than a twinspark    What about tailshaft sizes / connections / diff ratios / gearbox ratios. Does it sound like a good idea or should I get the transaxle out of a twinspark 75?

All comments will be much appreciated.

[scuzzyGTV]

First thing to note is that the 2.5 didn't come with a LSD. I've not yet got to install my TS box yet, so leave others to comment furthur.

[michaeljc]

Well thanks 'scuzzy' .... narrows my question down entirely to a TS 75 as the LSD is the main incentive for a change. Thanks. Any other comments re the swapover of TS transaxle into GTV gladly accepted too tho'

[BradGTV]

the ts, 3lts and auto 2.5 all have lsds,
the ts is the one to go for with its lower diff ratio

the ts will bolt into ur gtv, the input shaft is the same, as is the output flanges, the gear selector needs to be swaped with the one from your orginal box,

other than that the clutch and speedo drive are the main issues, but ill let some else clarify what exatly needs to be done!

[ANG156]

The TS gearbox fits perfect into the gtv and the cv shafts match with the output flanges without any problems. As far as the gear selector goes i have used the TS type in my Giulietta without any problems. The only problem is making the speedo work, which I have worked out and it doesn't involve using the signal convertor kit from jaycar. There is more involved than fit this kit to have an accurate working speedo.

And yes the 2.5L 75 was never fitted with an LSD diff.

[BradGTV]

giuilietta maybe, but the wheelbase of the gtv is shorter, so im pretty sure you cant used a isotalic shifter linkage unless you have one from a 85 gtv.

[ANG156]

This maybe so, I cant confirm this at all. How much longer is the isostatic shifting linkage compared to the gtv linkage. Have you tried using the spacer on the dedion as used on the 2.5l 75.

[BradGTV]

im 99% sure it is, as the propshafts are longer, i think alfetta, 75 and giulietta have the same wheelbase and u cant use either of thos props in a coupe.

[alfa duk]

 What i understand to be the easiest way is to change the selector shaft in the twinspark gearbox from iso to solid arm type and use the gtv's standard shift set up. You could use an isostatic from 85 but the 84 body where the shift link is needs to be altered to accept the extra bulk of the iso set up. Requires heat and a lump hammer to bash the body to shape or what i did was cut a hole in the area and make a removeable plate to suit as those that have had to deal with these mechanisms know that you just cant see or get to it with anything from underneath.