[AR4me]

I'm looking at front driveshaft engagement of a custom setup. I don't have other Milanos at the house at the moment and am wondering if someone can post the same pic as below, but from a stock Milano setup (from a car with the splined slip fit at the front).
Thanks,
Jes

 

[Brendan_LS]

dont have a pic but...

since nobody has piped up yet, I can say that mine sits with about 10mm of splines showing(with new guibos). It seems very tight a few years later, so im sure ill have to loosen the pinch bolt again and reposition it...its been slightly wobbly lately and all mounts are good.

nice front guibo BTW

 

[AR4me]

Thanks for the info. Then it is roughly similar to the above, which was the kind of confirmation I was looking for.
Jes

 

[Greg Gordon]

Jes, what are we looking at in your picture? Is that a donut cage of some kind?

Greg

 

[AR4me]

Not literally a cage, but a driveshaft coupling made as a "slice" of aluminum with 6 rubber inserst that have steel sleeves for the 6 bolts - things will stay together and not come flying trough the tunnel should the rubber fail. I posted pics a few years ago somewhere on the BB. This is on the 3.7 race car with one-piece carbon fiber driveshaft and close-ratio transaxle + race clutch from Richard. Alfetta stock driveshaft coupling is used at the back as per Richard's and Al's recipe.
Jes

 

[75evo]

Jes,

Have you run the engine on the 3.7 yet ? Im interested if that giubo will vibrate too much. If it is OK I will need to contact Alexis Walters for the guibo. Im not paying $500 for a set of new giubos and have it blow up in just a few thousand miles.

 

[AR4me]

Not at race pace yet, but I have driven it around the block etc. They had raced it a full season at the time I bought them from Alexis some 2-3 years ago.
Jes

 

[75evo]

How does your whole setup feel at low rpms? Does it vibrate a lot? Your setup sounds to be really stiff. Steel front donuts with rubber inserts, no center donut, maybe a rubber donut in the rear, and an unsprung disc?

 

[AR4me]

No, little vibration at low RPM. I have late Alfetta rear rubber coupling. The only drawback of the front (aluminum - not steel) coupling is that it is relatively heavy. I think I weighed it at some point to compare to a stock front coupling, but I don't recall the numbers. I spent a lot of time aligning the engine output with the transaxle input, resulting in the 1 cm spacers at the Milano transaxle front cross member being removed completely. I also modified the engine rear, transaxle rear, and transaxle side mounts to make them more stiff - got the recipe from Al Mitchell using polyurethane. The transaxle side mounts were cross drilled and bolted - OD of bolt slightly smaller than diameter of drill - standard by many.
Jes

 

[Jim K.]

One question here: I also have this splined yoke setup in my 3liter 12v car and I am about to use it with the 24v engine. The 75 1.8T does not come with this spline thing and these cars routinely put out 300-450hp with the std turbo front donut alone without any problems in the specific area. What then is the drawback (if any) by just using the simple setup (no splines). Of course, each system has its respective driveshaft.
Jim K.

 

[75evo]

I have the 1.8T style driveshaft too. Haven't had any more problems compared to the splined ones.

Only advantage I see is splined ones allows fore some adjustability on length. That's all.

 

[AR4me]

Only advantage I see is splined ones allows fore some adjustability on length. That's all.

Agree. It can be valuable if production specs on couplings etc isn't the greatest or other variability occurs due to modifications or aging - a slight offset and the couplings will be distorted when bolts are tightened which will likely accelerate wear. It is a nice feature for installing and removing the 1-piece CF driveshaft on my setup as I can slide it enough forward to clear the engagement tip of the Alfetta rear coupling at the transaxle, lower the front of the transaxle and slide the 1-piece CF driveshaft straight back, and then down at the front and forward out.
Jes

 

[Jim K.]

Now, if this spline thing was such a great idea, wouldn't you think they would also use it on the 1.8T also? Why just on the V6 cars? Are we missing something here? Could it just be a carry-over from the gtv6? Was this system meant to cure a specific problem? I haven't been able to find anything regarding this matter in Alfa literature.
Jim K.

 

[75evo]

Early Milano 2.5 V6s also had the 1.8T driveshafts. My car was an early (1986 Milano 2.5 V6.

Don't forget that The oil pan bolt patterns differed between early and late 2.5 V6s....also Alfa had 3 types of Milano trunk lids (very flimsy, flimsy, not so flimsy).... hmmm what else..... oh yes, oil warning light sensors differed...

Alfa continued with this tradition:

Brera bolt pattern 5x110
166 bolt pattern 5x108
GTA bolt pattern 5x98
Mito bolt pattern 4x98


BMW car bolt pattern: 5x120

Only thing I can think of us, maybe the splined driveshafts may not be the best for big HP cars. But then I think the ring and pinion would blow up first.

 

[Jim K.]

Hmmm, if I have time tomorrow, I'll go to the Alfa garage where my stuff is and I'll measure the two different driveshafts. I may take a couple of pics and post them here.
Jim K.

 

[75evo]

My 75's driveshaft is out, let me know if you need measurements and pics.

 

[Jim K.]

Well, for those who like riddles, here's a pic I took this morning of three Alfa 75 driveshafts. The one on top is from a 3liter, the middle one from a late (post 1990) 1.8T and the bottom one from a 'regular' 1.8T. Other than the splines, its interesting to note the diameter of the tubes, front and rear. I can't make sense out of this but its nice to know they all have the same length (the bottom one just looks longer as the 'nose' is a few inches off the ground). I'm still trying to decide which one to put on the 24v car... Maybe a roll of the dice?
Jim K.

 

[Gabor K.]

Hi Jim,

For what its worth, being used to my early GTV6(which has no splines) I remember I was surprised seing the splined shaft on a newer GTV6. I have always considered the splined shaft as a simplification of dismantling the propeller shaft.

G.K.

 

[75evo]

I would go with a hybrid, get both halves which have the smallest diameters, then have the whole assembly balanced. No sense in getting a thick shaft there.

 

[Jim K.]

Hey, Gabor, I don't suppose you feel your car had some kind of disadvantage not having the splined joint? I think I'm leaning in favor of not using it in the 24v.
US owners haven't seen cars without this feature! Here in Greece its the other way around -very few 3liter cars because of tax problems. In fact, they didn't believe this feature appeared on some later 1.8T's, until they saw my 1990 1.8T a few years back.
75evo, the hybrid idea sounds good; I'll also weigh the parts for more info.
Jim K.