Alfa Romeo Forums banner

1 - 20 of 20 Posts

·
Registered
Joined
·
89 Posts
Discussion Starter #1
My car has big driveshaft vibration.
Someone have told me that when someone changed the donuts or when the gearbox/clutch was repaired they didn´t assemble everything the way it was and because of that it is out of balance.
How can I solve this?

It is a big vibration, I can feel some parts of the interior of the car vibrating/doing noise when I rev the engine 3500-4000 plus rpm.
 

·
Registered
Joined
·
4,090 Posts
There are places that can balance driveshafts.
Jes
 

·
Registered
Joined
·
1,330 Posts
I'm no expert, but I have been told by every ALFA mechanic I've ever used, that before disassembling a drive shaft for Guibo replacement... you need to mark all the joints so they go back the way they started. Sometimes they use paint, sometimes yellow tire crayon.

Every ALFA mechanic knows this. So, I'm guessing you went to someone who is not familiar with ALFAs. The only way I've heard to correct this is to go back and try every possible connection combination until you find the original arrangement. This means days of work removing, turning, testing, and reassembling everything... until you've eliminated the vibration you didn't have before he touched your car.

I'd say your mechanic owes you a bunch of hours correcting what he screwed up. I ran into that once myself, in trying to use a mechanic who said he could work on any car. Same exact issue! I won't make that mistake again.

I'd be happy to be corrected, if someone out there does not agree.
 

·
Registered
Joined
·
214 Posts
If the support bearing beneath the shifter was replaced, most likely what they did was to pull the driveshaft apart, then did not reposition the splines in the same position where they were originally and you are out of balance. The marking everything is a safe move but not a matterof life and death, and I will tell you why. I once made that mistake during my early Alfa working years, I did not re-position things right and the whole thing was out of balance. I took the driveshaft to get balanced and spent quite a bit, then assembled the whole thing, at about 4000 RPM the front and center donuts shattered, the front put a whole in the bell housing and damaged the flywheel! I called DiFatta in Baltimore and he told me that all the cars are balanced nearly the same way and an interchange would be possible. He sold me a used driveshaft and sent it to me, I put it in and the car was as smooth as silk. I do not recall him marking anything, so, the new one went in the whichever way I put it in, the important thing is pretty much if you ever take it apart by the support bearing, (which I did many other times), to mark where it is and reassemble in the same position. I would look for another driveshaft and bill the mechanic who did the work. Also, to do things right, the best way it is usually to learn how to do it yourself. Its not too difficult, many people here could explain how, just let us know and we will guide you through it.
 

·
Premium Member
Joined
·
14,940 Posts
Loosen the pinch bolt for the splines behind the front giubo. Start the engine and let it idle for a minute or so, then tighten the pinch bolt. That might fix it.
 

·
Registered
Joined
·
390 Posts
i thought all 75's didnt have a spline / pinch bolt? only gtv6?
 

·
Registered
Joined
·
3,810 Posts
We had a problem with my son's 3 litre 75 driveshaft recently which was caused by incorrect assembly by the previous owner. That car always had a vibration which I had attributed to out of balance. It turned out that someone had probably knocked the rear coupling on with a hammer and pushed the ball joint cup on the end of the shaft off the ball, resulting in the driveshaft wobbling around inside the coupling. This led to the destruction of the couplings. One came off in several pieces! We had no idea this was happening and had taken the car in to replace the transaxle mounts. Whoever did that tried to correct the vibration by putting extra washers on one of the coupling bolts! My son was lucky he got there without the coupling exploding. Now with all new mounts, couplings and support bearing and assembly by an expert, the car is as smooth as silk. The moral is that you have to be careful to align that ball joint cup so that it slides nicely into position and not whack it with a hammer. It is possible that you might have the same problem.
 

·
Premium Member
Joined
·
14,940 Posts
i thought all 75's didnt have a spline / pinch bolt? only gtv6?
Dunno about 75's, maybe they are different, but I have had a few Milano driveshafts and they all had pinch bolts.
 

·
Registered
Joined
·
390 Posts
Dunno about 75's, maybe they are different, but I have had a few Milano driveshafts and they all had pinch bolts.
interesting, i have a driveshaft here, that has v6 donuts, but no pinch bolt / spline, i thought it was from 75 / milano, maybe its from a 90 then?
 

·
Registered
Joined
·
390 Posts
that explains it, back on topic...
 

·
Registered
Joined
·
89 Posts
Discussion Starter #13
Last friday the car went to the workshop to replace a rear bearing. I asked the mechanic to check if visually was everything ok with the transmition.
He told me that everything was fine unless the central support bearing.
He said the the rubber of the central support bearing is almost destroid.
Probabily thats the cause of the vibration.
 

·
Registered
Joined
·
89 Posts
Discussion Starter #14
I think I´m going to try to change de center suport bearing at home.
Is it dificult?
I think I have at home on my used spare parts a central suport bearing, so I only have to replace it...
 

·
Registered
Joined
·
1,330 Posts
As mentioned above... If you are going to try that yourself, remember to mark the metal yokes on each side of the rubber joint before taking anything apart. Crayola, or paint, on a matching front and rear tang, to make sure it goes back the way it was.

If you don't have that part on your shelf... IAP, Centerline, or Vick's can provide new ones.
 

·
Registered
Joined
·
214 Posts
Don't know if you started this job already, keep us posted on how goes it. In any case, as previously stated and as planetmojo (love the nick), reinforced, can't stress enough how careful you have to be, Just take your time as you pull the yoke apart and mark it even before you have the two halfs apart from each other.
 

·
Registered
Joined
·
1,330 Posts
as planetmojo (love the nick), reinforced, can't stress enough how careful you have to be,

Just take your time as you pull the yoke apart and mark it even before you have the two halfs apart from each other.
Dominus vobiscum, en espiri tu tuo!, on your project. A little Catholic blessing or something like that always helps on a first time thru.

PlanetJanet rhymed better... but then I'd have to grow breasts :- )
 

·
Registered
Joined
·
89 Posts
Discussion Starter #18
Don't know if you started this job already, keep us posted on how goes it. In any case, as previously stated and as planetmojo (love the nick), reinforced, can't stress enough how careful you have to be, Just take your time as you pull the yoke apart and mark it even before you have the two halfs apart from each other.
I haven´t done anything yet.
I´m repairing a 1.7 16V boxer engine to replace the one I have on my 33 16V QV. It had a big end bearing failure at 235.
So until the end of next week I wouldn´t do anything to it.
But first I will try it on a spare driveshaft I have at home. If it goes ok, then I will do it on the one that is on the car.
 

·
Registered
Joined
·
89 Posts
Discussion Starter #19
Problem solved.
I didn´t repair it my self.
Without the proper tools it is a nightmare to do.
So I toke the car to a workshop and they repair it.
I had a spare, complete and good condition driveshaft at home, so I asked them to replace it.
It was a 1h 30m job, so I waited and even helped on the repair.
The exaust had to be removed, and after that they replaced the driveshaft.
It was not easy to do even with all professional tools, so If I had to make it at home, I dont know If I could...
The central suport bearing rubber was destroid and the rear "donut" was also in bad shape.
Later I will post some pictures.
I paid 30 euros for the job.
 

·
Registered
Joined
·
89 Posts
Discussion Starter #20
Here are the pics...






I toke 2 different driveshafts that I had at home that I thought that were from a 75, but one of them is different. The one I replaced has 2 big "donuts" and 1 smaller in the middle. The different one has 3 small donuts and it doest fit...
Does someone know for wish model is this driveshaft?



Sorry about the quality, but I only had my mobile phone.
 
1 - 20 of 20 Posts
Top