ALFAGTV6.COM

[sammbo]

Hi Folks, I wonder if someone has some answers to my problem. The other day my Alfetta's Gearbox started whining. Soon after it made a crunching noise and the transaxle locked up. I pulled it down today and discovered the pinion gear was missing half it's teeth. I've been thinking about putting a stronger box in, but the later models all have senders for the speedo, while my car (1979) still has a cable. I thought about putting various pieces together (i.e. milano/75 and Alfetta) to make up a new stronger box. But I'm not sure if it's possible. What I was thinking was to use Milano gears and diff, and Alfetta case and pinion gear. That way I will have the original speedo working (maybe not accurate – but working). Has anyone tried this before? are the parts interchangeable ? I have 1 GTV that I'm restoring, a 3 ltr 75 and a 75 Twinspark, yet I still can't bear to see my old Alfetta in it's current sick state. So please help me, the pain is unbearable...
P.s. I hope I have the terms right - the part I'm calling the pinion gear the gear at the end of the shaft that goes into the Diff.

Thanks in Advance

Sam

[Mats]

Pinions and crown wheels are paired so you must use the output shaft and crown wheel from the same box.

[sammbo]

Thanks Mats.
I have a spare Alfetta box that I can use the Pinion and Crown gears from. I can then use the 75 gears. The problem is that I'm told the Alfetta Pinion and crown gears are the main points of failure on the Alfetta. I was told that when the 1800 Alfetta was upgraded to 2000, they kept the original 1800 gearbox and the crown gear and pinion are the weakest parts.
I was hoping to use all internal 75 bits, with the old casing and somehow make the old cable speedo still work.

Sam

P.s. when you say they are matched, do you mean from a ration point of view or are they uniquely matched from gearbox to gearbox?

[Mats]

Matched as in per model, a 4.1:1 75 TS output shaft can't be used with a 4.1:1 GTV crown wheel ans so on. They are not the same even though they have the same nuber of teeht.

I'm not 100% but I'm not sure the bearings are the same on the Alfetta vs the 75 type boxes.
Or do you mean 75 gearset in Alfetta casing + diff? Why not just use the complete 75 box and rework the speedo instead?

[sammbo]

Mats,
the 75 speedo is electronic with a sender etc ... the Alfetta I have has a cable. I wouldn't know where to start with re-working the speedo. I'm also very keen to keep the original look and feel on the Dashboard. So if I re-work the speedo, I may windup having to replace the actual speedo in the dash. Then I would have a different looking dial to the others.

[Mats]

I know the problem exactly since I have a 75 box in an Alfetta GTV.
There is TONS of info on this matter in the old forum, start digging...

[ar4me]

Mats,
So, is that why the speedo in your race car is never moving on those race videos of yours? Been wondering about that.
Jes

[Greg Gordon]

These Pinon Gears SUCK! So far we have had two different gear boxes shred pinion gear teeth. My theory is that metal fatigue and heat eventually kill them no matter what you do. Both failed boxes have been behind a mild 2.5 (165 hp max).
Someone needs to come up with a better gearbox for these cars.

[Mats]

Jes: Yep.

Greg: Haven't actually heard about these type of failures. Alfetta type box?
75 boxes are strong enough.

[Greg Gordon]

Mats, GTV6 3.42 boxes. First one was out of a race car and it failed after we used it for about 10,000 miles. We figured it fatigued due to racing and general abuse.

The second gear box was never abused and in good shape. It was on my dad's GTV6 for about 170,000+ miles and failed for no apparent reason. We took the box apart and everything else in it is OK so at least it's good for parts.