GTV 6 vibration after clutch replacement

[Fritzi]

i am quite bummed - I had a reputable Alfa/Italian Cars shop here in San Diego replace my worn out clutch incl. throw out bearing, flywheel etc (he bought the whole assembly for $800 at International Auto).

$1,500 later (he fixed a couple other minor issues) my car now vibrated at idle speed and rattled like a tin can of bolts at idle as if a throw out bearing is bad AND as if the driveshaft was loose.
First I thought those were two separate issues and took the car back to the shop.
The owner tells me that these cars (Milanos and GTV6s) are always problematic because nobody can balance the driveshaft anymore. He also said the rattle and vibration have the same source - driveshaft ! (since he replaced the throw out bearing and a couple other transaxle bearings in there).
I told him that I am aware of this and therefore you need to perfectly mark every washer, nut and donut, which he assured me had been done while removing the driveshaft from the transaxle.

I tell him that I owned 6 different Milanos and GTV6s in the last 10 years and that I have NEVER had any issues with the driveshaft. (and my Milano had 250,000mls when he was retired).
So I guess I was lucky in the past. The shop owner kept the car to see what he can do.
Picked it up yesterday and it is worse than before. What he also did was to adjust the idle speed close to 1500 rpm so the vibration would not be felt anymore. To clarify, the car ONLY vibrates when idling - it is still smooth as before at speed.
I called a bit upset saying I don't like how the car idles and I want the root problem => driveshaft fixed.
He said to bring it in again however I can tell that he is REALLY reluctant to mess around with the driveshaft again - he seems to have little hope to improve anything.

The car ran perfectly - had a trip up to San Francisco before the clutch replacement and the car was smooth at any speed. Now I really hate how the car vibrates - it is strong enough so you are concerned that it will jank out a transaxle bearing over time - it's like a massage chair - -only at idle though.
So my question is - what have you guys done to get this fixed - now that the damage is done?
I am happy to take it to another shop - I do a lot of repairs on it myself but this time I didn't want to have a car on jackstands for 2 weeks so I decided to have a "professional shop" do it.
Any advice?

thanks

[CrazyMan]

at one point the engine in my GTV6 was idling strange and it caused a strange harmonic vibration to cause the muffler to knock on the transmission and it was really clanky and vibrated a lot. It only happened during idle. This may not be your problem but i thought i would just give some input. what's weird to me is that if something would be out of balance i would think that i would get worse as rpm increased instead of the other way around but I am definitely no expert

got me stumped

[Alfar7]

You changed what? Maybe that is some of the issue?

Here`s some thoughts:

At idle you have little RPM to excite "minor " "weight" out of balance issues.
Your issue seems more like incorect aligmment of the Giubo solid points on the ends of each shaft. Unless they are correctly positioned the shaft tries to push apart. Major shake.

BUT THIS IS HIS CALF! HE HAS TO SUCKLE IT!!
Insist that the Flywheel and "Pre balanced" assembly be send it back to seller for replacement, and the problem be solved! (did they put it together the way it was assembled? Of course they did he says

Give him 10 working days and and ask for a rental car.

Get serious with him.

These assumptions that the Transaxle car driveshafts are impossible to put together is absolute bull$hit! He just does not know what he is doing. The shaft did not need to come apart for one thing!

Rj

[Alfaross69]

Quote:

Originally Posted by Fritzi i am quite bummed - I had a reputable Alfa/Italian Cars shop here in San Diego replace my worn out clutch incl. throw out bearing, flywheel etc (he bought the whole assembly for $800 at International Auto)......... ..........So my question is - what have you guys done to get this fixed - now that the damage is done? I am happy to take it to another shop - I do a lot of repairs on it myself but this time I didn't want to have a car on jackstands for 2 weeks so I decided to have a "professional shop" do it. Any advice? thanks

[sportiva]

Hello Fritzi

Your problem could be the positioning of the drive shaft [touque tube] to the gearbox yoke, there are only three ways to join them sometimes moving the shaft one position
fixes the vibration

sportiva

[sportiva]

Fritzi

Try repositioning the torque tube
remove the exhaust, undo the crossmember, dont undo the gearlinkage, remove the bolts on the torque tube, mark the position of the tube and the note which way bolts are positioned, jack up the de doin tube from the back this will move the gearbox down
and away from the guibo enough to reposition it use a large screwdriver to leaver it around

[sportiva]

dont jack the de doin tube to much as you might bend gearlinkage... just enough to seperate torque tube quibo from the yoke
most vibrations happen just off idle 1500 rpm and disappear as the revs rise
but on other cars with badly balanced shafts the more you rev the worse they get

[Naplesworkshops]

We had a GTV6 in the shop (over at Heavy Metal Alfa) with a terrible jingly rattle at idle...

It turned out that sometime in the past someone had fitted the pinch bolt on the driveshaft incorrectly. The yoke that it clamps to the shaft is threaded on one side and not on the other. Meaning that you CAN fit the bolt the wrong way round.... We fitted a new bolt (correctly), tourqued it down correctly, and the noise was gone.

When we have driveshafts out we usually try to run the car for a couple of minutes with that pinch bolt loose as well as the centre support nuts as loose as we dare. Also a good idea to "rev it up" a couple of times... this procedure will allow the shaft assembly to settle without any preload or unusual tension.

Lastly, I have seen very few GTV6s that wouldn't benefit from a new centre support bushing/hanger.

[sayporsha]

Greg Gordon has a good writeup on this:
Guibo, DS, Clutch

I hope the tech removed your driveshaft properly vs. bending it while muscling it out. The rattle could be a loose pinch bolt.

[sportiva]

fritzi

the pinch bolt refered to is at the front of the drive shaft [torque tube] near the engine , it is only if the torque tube was removed that it becomes a problem if the torque tube was NOT removed then the vibration is coming from components aft of the torque tube

[sportiva]

the problem could be
clutch disc alignment
throw out bearing [thrust race] push the clutch pedel in does the rattle go away
or the bearings in the clutch housing they are disturbed when the clutch flywheel is replaced