Alfa Romeo Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
122 Posts
Discussion Starter #1
I'm in need of a new driveshaft due to a broken piece on one of the couplings. I've read that these driveshafts need to be marked in a way that allows the halves to re-attach at the same points that were attached before the two halves were separated for proper balancing.

I'm looking at this one on eBay, and I, wondering if this is true, or if someone can say from the pics if there is any other reason to pass on this one. I've read that the driveshafts changed within the 1987 year, and my 1987 car was made in December of 1986. Of course I'm going to need new guibos, and I'm lamenting that expense.

Thanks in advance for any thoughts about this. My car is sitting idle until this issue is resolved, and I'm really missing it!

- Chad C.

Alfa Romeo Milano Driveshaft | eBay
 

·
Premium Member
Joined
·
848 Posts
Get a better driveshaft

Hi Chad

I would try and replace your existing drive-shaft with a drive-shaft that has a slip connection on the front like all GTV6's had, and some Milano's had.

The first transaxle cars, the Alfetta, had the front Guibo attached to the engine flywheel, and then the drive-shaft was attached directly to the front Guibo.

With the advent of the GTV6. Alfa improved the drive-shaft design, by making the front end of the drive-shaft terminate in a splined section. The front Guibo was mounted to a separate splined carrier.

The splined drive-shaft slid into the splined carrier and was tightened down by a pinch bolt. This was a big step forward. Not only did it ease drive-shaft R&R, but it helped with vibration issues.

Then with the Milano. Alfa regressed back to the crappy Alfetta setup; no splined carrier!

Some Milano have a splined drive-shaft/ carrier setup and some don't. All the Verde's I've worked on have had the splined drive-shaft/ carrier. Lot's of 2.5 Milanos have the splined drive-shaft/ carrier, and lots don't.

I don't know if this was a running production change, or if Alfa dealer's routinely upgraded the drive-shaft under the warranty period, or what. In any event the splined drive-shaft/ carrier is better, and is a upgrade worth pursuing.

The front half of the Milano drive-shaft is identical to the front half of the GTV6 drive-shaft. The back half of the Milano drive-shaft is longer, than the back half of the GTV6 drive-shaft.

If you can't find a complete Milano splined drive-shaft/ carrier setup, then you can make one with a GTV6 front and a Milano back-half. Just maintain the correct phasing between the two halves of the drive-shaft.

You don't say in your post which end of your drive-shaft (the engine side or the transaxle side) had the broken ear. If it was the front end, you can still reuse your old Milano rear section.

Also don't be throwing away old drive-shafts, even broken ones. They still have useable parts or can be repaired someday.

Hope this helps.
 

·
Registered
Joined
·
168 Posts
Great info on the driveshaft differences. My 87 2.5 Milano Gold is a bit buzzy in the driveline. I am going to visit my enabling buddy this weekend (he got me started on Alfas). We will poke around under the Milano, check condition of guibos and determine if we have the splined front section.

He has a parts Milano Platinum (w/LSD transaxle I think) so if mine has the older style and the Platinum has newer there is another part to pick off of it. It will be good practice to remove the shaft out of the parts car in any case...
 

·
Registered
Joined
·
4,340 Posts
I have never seen ANY American market V6 transaxle car with anything other than the splined yoke at the front of the driveshaft. The only difference I have seen on any of those cars is the center Giubo (some have the thin disc version, others have the chunkier version that matches more closely the appearance of the front and rear Giubos).

Also, in terms of swapping back halves of the shaft between GTV6 to Milano or vice versa, there is no way to determine what phasing is correct - there is not a reference mark on the front vs. rear shaft to assemble any given correct way. Beyond that, if the center support carrier and bearing is renewed and thus the intermediate yoke removed, the splines of the intermediate yoke must be put together the same way on the shaft or it can be one or a few splines off front vs. rear. That being the case, you can literally assemble the driveshaft hundreds of ways out of "phase." The front splined section of the V6 driveshafts only enters the carrier yoke one way (there is a flattened section of the splines that corresponds to the notch cut for the pinch bolt).

Depending on what you believe (either that the front and back halves are balanced separately, or if the front and back are balanced together) you can experiment. However, in dozens of driveshaft trials have not had a single success in swapping front vs back halves from other shafts whether supposedly in phase or out of phase without noticeable vibration.
 

·
Premium Member
Joined
·
14,037 Posts
Hi Rob,
I have a "spare" driveshaft from a Milano Gold that is separated and not marked. Is there much possibility that it will ever be of use to me for my GTV6? It is taking up space.
Thanks.
 

·
Registered
Joined
·
4,340 Posts
Hi Rob,
I have a "spare" driveshaft from a Milano Gold that is separated and not marked. Is there much possibility that it will ever be of use to me in my GTV6? It is taking up space.
Thanks.
Partly, yes - the yokes, centering bearings and seals, hardware, seals, etc. are interchangeable. The front and rear Giubos are definitely interchangeable, and the centers can be (type to type). IF and only if you have a driveshaft balance shop that can reliably test such things, then the front section of your spare Milano shaft could theoretically be useful for your GTV6 if you were to have it balanced with your rear half GTV6. Again, depends on who you ask. RJ's favorite driveshaft is to use the front half of a V6 shaft with a rear Alfetta shaft (can't remember early vs late) w/ corresponding Alfetta yoke at transaxle. Not sure what his experience is with balancing them but he says that the centering device is much more positive at the transaxle.

If your spare Milano shaft is separated and not marked clearly w/ paint or chisel, sometimes you can faintly make out where it was bolted together by corrosion or dirt markings on the Giubos or fasteners (this allowed me to save a GTV6 shaft and keep it in balance!). Nutshell: yours would be more useful to a Milano owner who needs a complete shaft.

To R/R the center support and bearing, you must remove the center yoke and it needs a 36mm socket for 2 thin jam nuts. The socket must be ground or turned down to fit in the yoke itself. I have a high quality impact socket that was turned on a lathe you can borrow if you need for this job.
 

·
Premium Member
Joined
·
14,037 Posts
That's useful information. My current driveshaft has a center support that was beefed up by Al Mitchell and it has done minimal mileage since. I once had a complete GTV driveshaft balanced at a truck driveline place in Columbia. The guy who did the work owned a Fiat Spider and it vibrated afterwards, so I have no confidence in getting that work done properly around here. Maybe there are some NASCAR boys in Charlotte who could do it.
 

·
Registered
Joined
·
484 Posts
driveshaft replacement

I understand I am not comparing apples to apples here, but I destroyed the rear half of my Alfetta driveshaft and replaced it with a used rear section, had it balanced as a unit by a local driveline shop and have had ZERO problems with it. My guy had a special request to make it work. He needed the rear yoke and a piece of the input shaft to properly mount it to the balancer.
 
1 - 9 of 9 Posts
Top