Just did driveshaft, exhaust

CrowBar · #1 (**permalink**) 11-30-2003, 11:20 PM

Totally successful day...center support broke into a million pieces on Friday, so replaced it today.

Now you all know I am paranoid....After I assembled everything I test drove it...very smooth and ran great. Then I woke up thinking to myself "did I have the bracket on the center support spun in the correct way when I tied it down??!

So I was wondering if it was even physically possible to mount it with the bracket turned the wrong way? Knowing this would save me having to remove the heat shield again and look.

Thanks
-CB

AlfaRacer75 · #2 (**permalink**) 12-01-2003, 12:54 PM

A long time ago I assembled the driveshaft with the center support in the wrong way. When I started the car one of the donuts was rubbing the tunnel and making a horrible noise.

I'd say that if yours started and ran smoothly then you shouldn't worry.

junglejustice · #3 (**permalink**) 12-01-2003, 01:15 PM

...that you would need to rebalance the driveshaft afterward?

After replacing all of my donuts, supports etc on the driveline recently, I now have this slight vibration/hum between 68mph and 80mph...

Anything I should know?

I can depress the clutch in that speed range, take it out of gear, drop the clutch again and even turn the engine off (which would make the driveshaft stop turning, right?) and the hum is still there..?

CrowBar · #4 (**permalink**) 12-01-2003, 01:18 PM

If you turn the engine off and the hum is still there, it's not the driveshaft. The driveshaft is only spinning when the engine is running or being dragged by the gearbox. Maybe a wheel bearing in the front, or possibly a failing CV joint in the rear (there are 4)

-CB

CrowBar · #5 (**permalink**) 12-01-2003, 01:21 PM

Also - Balancing is not a big deal, really. Just mark everything so that the yokes line up the same way, and mark every bolt and washer to make sure they are re-used in the same place. I did this and it is smooth as silk.

junglejustice · #6 (**permalink**) 12-01-2003, 08:43 PM

Odly enough:

Two of the bolts on the forward dounut was of a different size to the rest of em...? What's up with that? Previous monkeys?

We did mark them and it seems fine but man, I lost a balancing weight on the prop-shaft in my Q45 and boy! It sounded like a seriously bent rim!

Vibration for sure coming from the left front and yes, engine turned of (out of gear) the prop is not spinning - same as on my old Alfetta Sedan....

AlfaRacer75 · #7 (**permalink**) 12-01-2003, 11:56 PM

Alfa supposedly used different weight nuts to finish balance the driveshaft, But do you mean they were a different size as in not 19mm? I've never seen that...

CrowBar · #8 (**permalink**) 12-02-2003, 02:17 AM

When I did mine, they all were the same size per donut...19 on the rear and font donuts, 17 everywhere else. The only thing different with the nuts that I could see was the color of the ends of the threads. Some were yellow, others green, others black. That may signify something...not sure. I was told though that it is important to keep up with it down to the washer. I can't imagine that with FIAT's "quality control" procedures, that they would bother spending THAT much time balancing this thing to perfection.

-CB

CrowBar · #9 (**permalink**) 12-02-2003, 02:21 AM

Jungle - different sized nuts on the same donut IS PREVIOUS MONKEYS. They are suppposed to be all 19mm on front and rear donuts, 17mm on the carrier bearing. But the vibration you're feeling can't be the driveshaft....t'aint spinnin. Bet on a wheel bearing, wheel out-of-round, etc.

AlfaRacer75 · #10 (**permalink**) 12-02-2003, 12:23 PM

I have always been told to mark all bolts, nuts and washers to put them back exactly where they came from to maintain balance.

I could never imagine Alfa having a guy sit there and put different nuts on certain places to balance the shaft. The shaft is already balanced by small plates welded onto the shafts.

After a couple years I got tired of trying to keep track of all the nuts & bolts and I no longer mark them or anything and it's never caused any vibrations that I can feel. Non of my driveshafts were PERFECTLY smooth to begin with, but mixing up the nuts & bolts never made anything worse. These cars have some driveshaft vibration no matter what. Ask Nizam, he just had his driveshaft balanced donuts, bolts, clutch and all... and it's better now but still not completely smooth. DEAL WITH IT!

Or go buy a Lexus

CrowBar · #11 (**permalink**) 12-02-2003, 12:39 PM

MY ONLY CONTACT WITH LEXUS IS SEEING THEIR HEADLIGHTS GETTING SMALLER IN MY REAR-VIEW.

-CB

JoeCab · #12 (**permalink**) 12-02-2003, 01:21 PM

Chip,

While I don't find driveline vibration to be a huge deal, my car simply doesn't have any. Several mechanics who have driven it commented on it right away. I can't take credit for it, it was that way when I bought the car.

Also, several people I know who have purchased and installed new factory driveshafts (come complete with all donuts) report that they are silky smooth as well. This was done to correct a driveshaft that couldn't be balanced conventionally after many tries.

So, it is possible...

Joe

nizam · #13 (**permalink**) 12-02-2003, 02:55 PM

Yup, my car had a driveshaft/clutch assembly that was smooth as glass. You wouldn't have believed it was a Milano.

The keyword is 'was', because I've since lost that luxury, and am trying very hard to get back there.

The problem, I think, is that my balance guy does not understand that the driveshaft runs at engine speed. I'll have to inform him of that when I bring him the next driveshaft.

junglejustice · #14 (**permalink**) 12-04-2003, 05:13 PM

A good way to make sure that your "balance guyc" never forgets the unique attributes of the Milano driveline, is to tell him to keep the engine running (but keep it out of gear "for safety reasons") while checking for "drive-line slop"... tell him to touch it - that'll teach him.

Tell him that you are only able to replicate the problem at night; tell him to perform the check then....

He'll never forget the experience.

What I'll never forget is the experience of trying to fish African highveld monkey grass out from underneath the car (particularly the grass wrapped around the prop-shaft after some spirited "rally" driving at night on the unpaved farm-roads in my Alfetta Sedan landed my date and I in the weeds!

I had the lights on (so that I could at least see something from the reflection in the bushes ahead of the car) and I left the car running, so that I wouldn't run the battery down...

Hellova surprise I got when I stuck my arm under there.... I think I chipped a nail.

alfanfl · #15 (**permalink**) 12-07-2003, 05:05 PM

I just picked up a 87 Milano and when I approach 2000 RPM I get a vibration/rumble. It stops when I take it out of gear. I crawled under the car and took a look at one of the donuts, I think it was the center one, and I couldn't see anything obvious. Should I go ahead and replace the donuts?