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I’m about to have the gearbox replaced on my ’84 GTV6 (badly-worn syncros). The people here in Melbourne who’ve done a few have given me 2 options – (1) replace the gears with closer-ratio ones from a 4-cyl Alfetta, giving a higher 1st gear and lower 5th, which they point out besides making 1st more useful will reduce the work of the syncros, especially on second, or (2) drop in a gearbox from an Alfa 75 (Milano). They say this is a better option (i.e. a better gearbox), but is more expensive. It apparently requires a new diff also, but I end up with a limited slip diff, if that is any real advantage. I wonder if anyone has gone either of these routes or has other comments.

dave!

Depends a little bit what You want. If You can get Yoyur hands on a 3.0 gear box from a 75 you´ll get smoother ride. Also i has 25% diff.
If you want something a bit "sportier" maybe for some track time, I´d recomend the 75 TS gear box. Tighter and shorter and 25% diff. I have one in my track car (75 3.0) and it is great for the track.

I hope I didn´t confuse you more!

Seb

Dave,

as Seb said, gearbox selection depends on the use of the car and your needs.

With the combination of final drive ratios and gear ratios one can create interesting gearbox.

The original final drive of the GTV6 is in most cases 4.1:1.
The Milano has 3.54:1
The TS has 4.1:1
The Turbo 3.9:1
The Alfetta around 3.8:1 (not sure about this ratio)
(There are also 4.3:1 ratios available)

In my opinion, the 4.1:1 GTV6 gearbox is a good compromise for normal, everyday use. Good for acceleration, and reasonable on highway cruising. The only thing I don't like, is the very short 3.5:1 first gear.

The TS and GTV6 gearbox differs in 1st and 2nd gear (longer in TS -> closer ratios), and LSD, therefore is you liked the GTV6 box, you will probably like the TS unit as well, besides the advatages you expect.
The 3.54 Milano gearbox is too long for a stock engine. Ideal for highway cruising, but the car will loose its agility.

If you can find maching closer ratio gears from a TS os Milano or other boxes, they can be fitted to a GTV6 gearbox, but it's possible to get a whole TS unit.

In any case take care of the shifting linkage and speedo connections!

If you are interested in exact ratio number I can look after.

DaveR wrote: higher 1st gear and lower 5th

Does 'higher' meen 'longer'? Eg. 2.8:1 instead of 3.5:1, am I right?

In the question of 5th gear, as far as I know all of the above mentioned models share 0.78:1.

I have a 75 TS gearbox on my GTV6. It's quite a common mod for track cars here in the UK and I'd recommend it. First and second gears are longer and more usable and it has the limited slip diff (a big advantage when trying to get the power down on the exit from a corner).

In my opinion the box from the 3-litre 75 is not such a good option. 4th & 5th are too tall for the 75, let alone the GTV6 (assuming we're talking about a stock engine).

Thank you very much for all that good stuff. Yes, higher to me means longer - in case of 1st, 2.8 instead of 3.5, as ingegnere says. AFA what you say about 5th being the same (0.78)in all boxes, I maybe misunderstood the shop engineer - he might have said I'd end up with a lower (shorter) final drive in 5th because of the diff ratio, but what diff he meant I don't recall. Will check back.

I think the Alfetta Transaxle had a 0.83 5th.
Merril

Maybe I misunderstood the Taiwan 75's owners &engineer.They said big power should use longer gearbox...like the longest 75 2.5Milano(3.54:1)
but I saw many people in the group take TS gearbox used in gtv6......
now I have a few question~
1:I have a 75 MILANO 2.5, but the 3.0 engine(from 164 have 192hp/25kgw)was instead of 75 Milano 2.5 engine & use 2.0TS gearbox.I fell TS gearbox transmisson is too close be used in the 3.0engine, In city for drive is bed for fun.I can't feel all the power of engine downright. 1st & 2st let the engine auick over rev.
But some gtv6 fans here use 3.0engine & original gearbox. gtv6 gearbox 1st ~ 4st more close than the ts.Can't you boring for the collocation???

2:Tonight my TS gearbox was broken....I haven't to found the answer yet....!Maybe is the LSD maybe is the gearbox!!
IS TS gearbox unsupportable??????
Tomorrow I will get a GTV6 gearbox, maybe I take it on my 75 3.0 but need deep think!

3:What different in TS gearbox & GTV6 or 2.5??
IS fatigue strength on construction?

Before I have so many ts and 1.8TB, but over 2.5 is so diffcult on me.

The knowledge in Taiwan is a few.because over 2.0 in Taiwan just only Milano2.5-auto

please do me a favor.....thanks a lot

artist_alfa75

About the ratios, here's what I've found among my documents:

Model; 1st gear; 2nd gear; 3rd gear; 4th gear; 5th gear; final drive

GTV6; 3,500; 1,956; 1,345; 1,026; 0,780; 4,10:1
75 2,0TS; 2,875; 1,720; 1,226; 0,946; 0,780; 4,10:1
75 3,0; 2,875; 1,720; 1,226; 0,946; 0,780; 3,545:1
75 1,8T; 2,875; 1,720; 1,226; 0,946; 0,780; 3,909:1
75 2,5; 2,875; 1,720; 1,226; 0,946; 0,780; 4,10:1 (QV) and 3,545:1 (Platinum)

Hope this will help a little.

As you can see, the 75 gearbox ratios are all the same, they only differ in final drive. The GTV6 gearbox is completely different. Gear ratios in 75 boxes are closer, and maybe more usable than the GTV6 unit. Gear pairs are changeable, so you can build a custom gearbox you like. (I was thinking of using the 1st and 2nd of a 75, and the rest from the GTV6, and a turbo final drive).

Depending on your taste of driving what you choose. Short final drive ratio supports acceleration, long ratio supports highway cruising. If you are a Grand Tourer, choose the stock 3,0 box to your 3.0, I would suggest.

yep, that sounds right, except its the verde with the 3.0, and that means the 3.55:1 final diff...

the plat has the 4.1:1

there are material differences b/w the gtv6 box and the milano/75... the gtv6 for ex, uses magnesium extensively in the gearbox IIRC, perhaps heavier gears as well.

We are talking rest-of-the-world model names now, seems like the importer renamed just about everything when importing the Alfas into the US...

Link to List

ingegnere
thanks a lot
I think the 3.0box is the best for 3.0enigne
just it's no any 3.0box in Taiwan
I take a 1.8TB-box for the 3.0,maybe the choose is better on the road in Taiwan!

But I just unbelievable why my ts-box damage so quick in 3.0engine......Does yours never happen
the ts-box fit on my 3.0~~uncontrovertible the
acceleration let fell so good...fast as fast , and the ts-box easy get here, I just afraid broke again......

Joey...
you mean the material are different??
Sorry~~I don't know what is the ''IIRC''?
All of the boxs looks like the same

Mats
thanks the info.....

somebody can tell me what the differential ratio can let the 3.0engine really run to 220~230km/h & 0-100km/h under 8sec......

I can't count the result in equation....！

The TS box should give you everything except top speed and maybe cruising comfort.
Maybe the clutch broke? The TS clutch is not the same as the V6 and Turbo.
Box itself should be as strong as the V6 or Turbo.

I second Mats' opinion.

AFAIK, the boxes are identical.
The TS clutch doesn't last long behind a 1.8T engine. Don't ask how I know