ALFAGTV6.COM

[patanga]

Hi members. Is any one able to advise me how to confirm if an Alfa 75 3.0 might have a LSD fitted. I believe that all of the 3.0L models and 1.8T's came standard with the LSD but I'm hoping there is a way of checking without having to open the side of the transmission.

Next question, are there any differences in the forward gears and final drive ratios between the models?.. A list of the ratios and what is being used in competition would be great.

Thanks.
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[Giuliettaevo2]

Best option is to take the sidecover off and have a look. that way you can also count the teeth of ring and pinionwheel to know the gearing. there is no marking on the outside.

75 gearbox has the same ratios through the gears for all models, just differences in final ratio. ( 4,3:1 for 1.8/ 4,1 for TS/ 3,9 for Tb/ 3.5 for 3.0 for example).

What are you looking for? 3.0 gearbox is not really suited for racing due to long final drive.

[patanga]

Hi and thanks for your reply. I am not looking for a full competition car but I was thinking of using a 3.0L for club sprints etc as well as my daily drive car. Is it possible to swap the final drive crown wheel and pinion out of a 2.5L LSD transmission into the 3.0L unit to reduce the ratio?. I guess the challenge would then be in finding a suitable set of gears.

[Giuliettaevo2]

An easy option would be to use a 75 TS gearbox if that's available. You then just need to swap the clutch and driveshaft stubs over.

The gearboxes are quite similar between the different vehicles, swapping parts is possible. But if it's possible to use another ring and pinion in a 3.0 geabox i can't really tell you. Maybe somebody like Kevin can tell you that, he has opened up a few boxes and also has a racecar GTV6 so he might now a good combination for you.

[patanga]

I was mainly interested in the 3.0L because of the LSD diff as standard fitment. I believe that the crown wheel and pinion gears may also have a bigger surface area in the LSD transmissions. I figured that might also be a better option in the punishing environment on the race circuit. I had also heard that the non LSD diffs did not lend themselves as well to competition use due to wheel spin through corners. Can you tell me how I might get in contact with Kevin to ask? Bedankt.

[kevin]

The 10/43 suits the 2.5 and 3.0 while the 10/39 is difficult to pull. But what some the guys are doing is using the 10/39 crown and pinion as its bigger than the 10/43 then changing all the ratio in the gear sets to get the extra strenght. I am using the 10/43 and 10/41 but to be honest with the 3.7liter motor i have got so lazy it make not much difference to me. As mentioned above by EVO the best is 10/43 and replace half shafts and dont forget to change the tube that the thrust bearing slides over. The 10/43 has 27mm tube while the 10/41 has a 30mm tube. This rattle it creates will keep you puzzled for at least three gearbox pulls , prop balancing etc.

[patanga]

Hi Kevin. I'm new to the Alfa V6 transaxle scene. I presume you are the kevin that Giuliettaevo2 was referring to in his post above. I am looking at a 3.0L 75 to buy. I have learned that the final drive ratio in the 3.0L model (4.3:1) may be too tall for performance driving use. Is it viable to swap the crown wheel and pinion from a 3.5:1 final drive transmission into the 3.0L unit? The car I'm looking at has low mileage and the transmission feels to be in good order. Alternatively can I swap out the LSD parts from the 3.0L into a TS trans?

I've also heard that timing belt adjuster bearings may no longer be available for these engines and that clutches are stupidly expensive. Is this true? I'm keen to learn if these motors & transaxles have a viable future in terms of keeping them on the road & track. Many thanks. Great GTV posts by the way

[kevin]

The final drive ratios are according to giuliettaevo mail. As mentioned it would be ideal to get the box out a 75 turbo as it had an 10/43 with an ls. The irony is i have gathered my info from all the other guys on the forum which have helped me to learn about whats out there. Hence i imported a 75 turbo box then discoverd what mods to do. The Ls units to me appear identical on the 3.0 and 1.8 turbo and i have used both with my own set up. This will put you on the correct path. Regarding parts and bearings overseas I cant help as im on southern tip of serf efrika. You will have to findout from your local dutchman.

[Zagato]

I thoght the Turbo had 10/39?

[kevin]

I may be mistaken as we never got a 75 here but the box i got was a 10 : 43 with ls and the smaller half shafts. Please check . Maybe some else over your side can confirm.
The only cars in south africa that came with 10:43 was our 1600 alfetta and our limited gtv 3.0 L. All our gtv 2.5 came with 10: 41 here.

[Zagato]

10/43 is 75TS with LSD.

[Giuliettaevo2]

TB is 10/39 with the bigger halfshafts and the big pull-type clutch. 1 on 1 exchangeable with the v6 boxes. same ratio as the SZ/RZ boxes.

TS should be 4,1 ratio with LSD and the smaller shafts and push type clutch.

4.3 with LSD is unknown to me. Should be an 1800 box but those came without the LSD.

[patanga]

My mistake guys.. My earlier post mentioned that I thought the 3.0L 75 had a 4.3:1 final drive when in fact it is more likely to be the taller 3.5:1. So if I understood everything correctly a 75TS box with 4.1:1 would be a good match in the 3.0L 75 and to then fit the LSD from the 3.0L 3.5:1 transaxle at some later time?... I don't think the 75 turbo or the 1.8 ever came to this country so the 3.9:1 or 4.3:1 would be difficult to find here.

[MD]

No, you still got it wrong.
Fit the TS transaxle complete. It has the right ratios and the LSD already.
You could refresh it all before installation to be sure you have a good servicable unit in place.

[kevin]

Patanga, go to performance thread and check under gear sets for interesting reading.