ALFAGTV6.COM

matt · Post by **matt** » Tue Aug 23, 2005 12:30 am

Hi all could a driveshaft guru please tell me what the spherical bearing is for in the driveshaft centre support bearing assembly. Does it allow the driveshaft to pivot a bit under load? and how important is it?? I think it could be the source of an intermitent rattle and was informed by a spare parts supplier they're no longer available. Has someone fixed this or had noise from it or mended an old one with shims etc? I can get a centre support bearing but i don't think its the source of noise because theres no sag/"rumble" or vibration associated with this rattle. and what makes this funny i had clutch assembly out on the weekend and replaced centre muffler for an known rattle( something loose in it) .....put it all back together and now got different intermitent rattle....damn it

Thanks Matt

darryl longley · Post by **darryl longley** » Mon Nov 14, 2005 11:47 am

the rattle which sounds like a bell ringing when on slow idle and on switching off can be caused by the the shaft hitting the flywheel bell housing. this is easily solved by placing the appropiate spacers between the pin support and the fixing bracket try this very simple but effective remedy

Scott in MN · Post by **Scott in MN** » Tue Nov 15, 2005 5:29 am

"pin support and the fixing bracket" ??
Darryl, not sure what you are talking about here. Where are these items?

Mat, the center bearing was not the rattle source on my car. I'd be surprised if it was on yours.

darryl longley · Post by **darryl longley** » Tue Nov 15, 2005 6:39 am

The pin support is at the end of the bellhousing which passes through the rubber mounting (i.e the rear engine mounting) and fixes to the chassis. if there is no spacer on this point the prop can run very close to the bellhousing and what tends to happen is when you switch off the engine as the prop slows to a stop it may catch the bellhousing

matt · Post by **matt** » Tue Nov 15, 2005 10:06 pm

Thanks Darryl, when i removed the driveshaft the spacers where in place as i undid the nuts on the "rear eng' mount" to allow a bit more space between the chassis and bell housing to pull the driveshaft through, the rear engine mount looked good and the spacers where there.
Scott have you fixed that rattle, what was it? Its hard to say one thing or another really because if we had both cars running side by side it could be a totally different sounding rattle, i just assumed my rattle was centre bearing because when i o'hauled the whole driveshaft the rattle went away, i changed all guibo's, centre bearing + rubber support and greased everything, out of these changes i thought centre bearing most likely?

Scott in MN · Post by **Scott in MN** » Wed Nov 16, 2005 6:05 am

No I have not fixed my rattle yet. I haven't put any time into it as the car is tucked away for winter now.

I plan on checking taking a look at these "spacers" though as soon as I can. How thick are they? I assume they fit between the rear mounts horizontal pin and the body, right? I want to make sure mine are there.

matt · Post by **matt** » Wed Nov 16, 2005 12:23 pm

Hi Scott you're right, on my car these spacers are as thick as the nut holding them in place, i wonder how the thickness of this spacer is determined?..........it must be done by the factory somehow to allow for slight variations in alignment because of eng mounts, centre bearing mouts and gearbox mounts etc
i read somewhere on the forum with the driveshaft out a small pen laser was used at the centre of the flywheel to put a red dot on the centre of the clutch yoke and then using shims on gearbox and eng mounts to achieve pefect alignment. Sounded like a great idea to me, it was for a one piece carbon fibre driveshaft tho'

Scott in MN · Post by **Scott in MN** » Mon Nov 21, 2005 6:04 am

Dealing with these spacers. This is the location right? Between the horizontal pin of the rear mount and the body attachment points.

Mine does not have any spacers. Someone must have left them out. Or did they? Does anyone not have spacers here? Matt says his spacers are about the thickness of a nut (~6 mm). What is the thickness of the spacers you have on your car?

Thanks

SamW · Post by **SamW** » Mon Nov 21, 2005 6:37 am

I don't have any on mine, or on my Verde.

matt · Post by **matt** » Sun Nov 27, 2005 11:34 pm

Yep thats the right location, my engine is a 4 cylinder so the rear mount is a little different to your photo, it only has two bolts mounted to the chassis for the engine mount to attach and the spacer is between the two, looking at that photo maybe the V6's don't have a spacer like the 4 cylinder

are the two metal plates either side of the rear eng' mount that are bolted to the chassis flat or raised a few mm where the rear eng mount bolts attach?
I'll take a photo and post tuesday, been away last couple weeks

MerrilGordon · Post by **MerrilGordon** » Mon Nov 28, 2005 11:51 am

My car has spacers shown just where the arrows point.
I remember an earlier discussion regarding alignment, can't think of the guys name at the moment but he's the one who developed the carbon fiber one piece driveshaft and posts regularly on this forum. He used lazer pointers to align the engine with the transmission. I can't remember if he messed much with the front engine mounts, but it's rather easy to perform some alignment by changing the rear two spacer's thickness. I can imagine with no spacers at all there could be some clearance issues that might be causing the noise.

Merril

Barry · Post by **Barry** » Mon Nov 28, 2005 7:23 pm

Mat,bells an stuff are caused by the split bushes or bearing being us..
Unless you frnt coupling is totally buggered,the shaft will not touch the bellhousing-have done plenty and never have there been teltales of touching..Split bushes are still available brand new,we import them fron AFRA in Italy...Almost all components are still available from AFRA..

Dont leave this as the spigot the bush attaches to will also eventually wear and then its a mission...

matt · Post by **matt** » Mon Nov 28, 2005 11:56 pm

Thanks Barry, i had the whole lot apart a few weeks back and thought my centre bearing was ok and wondered what else could cause the noise but in the end i replaced the guibos,cen' bearing and rubber suppport and the noise went away so i assume the centre bearing was the culprit
By the sound of it these spacers make bugger all difference if you re driveshaft is in good nick?
Scott here's that pic for what its worth(i'm not a good photographer)

spacer about as thick as the nut holding in place......

darryl longley · Post by **darryl longley** » Tue Nov 29, 2005 5:57 am

Hello again iknow you guys all know your cars but the spacers do make a difference to the clearance on the prop hitting (only slightly) the bellhousing. I dont know if you have haynes manuals in the states but over here in the UK even the haynes manual mentions on page 98 in the fault diagnosis section under symptom:"knocking under starting decceleration or gear changing" reason "rear engine mounting fouling shaft" Im not saying this is the only possible reason for your noises but it is one

Tamariini · Post by **Tamariini** » Sat Jul 12, 2008 2:06 am

Hi everyone!

I found this pic on the 75/milano manual but it does not tell what clearance should V6 engines have between bellhousing and propshaft. Does any of you know the correct clearance?

I'm really having hard time trying to get my milano running without vibrations. It's originally TS but has now 3.0 taken from 164 and now with single turbo install. I have renewed all guibos and bearings on the propshaft and had it rebalanced but still it vibrates. I think it must be misaligned. Any ideas how i could fix it? Thanks.

-Marco

ALFAGTV6.COM

Driveshaft centre bearing..

Center bearing