Just finished the axle project and took the car for a test drive with new tires and all. I was cruising at about 80 mph when a loud bang under the car made my you-know-what pucker up, it sounded like something let loose from the drive shaft. I thought maybe I forgot a cotter pin and a nut flew off. I took the car slowly home, raised it to find out that a chunk of the drive shaft donut was missing.
Question, what would be the best/easiest way to replace the donut? Because of the drives haft "mushroom" the donut will not just fall down once unbolted. I am thinking the drive shaft needs to be disconnected from both ends and shimmied forward to let the donut fall off.
John,
three things :
first,
the cotten pin heads should compleetly disappear in the groove of the big castle nuts,
there is extremly few space between these nuts and the nuts of the flange of the rear axle.
would not surprise me if these are all flat now or cut off.
second,
the whole rearbridge must settle after the first bump in the road this could make this bang too.
also its trying to find the most relaxed position.
third,
the find out if there is noise or a singing king and crown wheel 120mph is a bit too fast,
We believe all here your car is capable to do so.
Hi Cornelis, thanks, but I was going 80mph not 120 mph. As you can see the missing piece from the donut and it left a mark on the tunnel, where it hit.
John Vardanian wrote:Hi Cornelis, thanks, but I was going 80mph not 120 mph. As you can see the missing piece from the donut and it left a mark on the tunnel, where it hit.
john
John,
I mixed up kmh with mph you know the discrepancy on the dial with real speed is hugh.
secure wire for the drainplug below for those who don´t understand.
John Vardanian wrote:Just finished the axle project and took the car for a test drive with new tires and all. I was cruising at about 80 mph when a loud bang under the car made my you-know-what pucker up, it sounded like something let loose from the drive shaft. I thought maybe I forgot a cotter pin and a nut flew off. I took the car slowly home, raised it to find out that a chunk of the drive shaft donut was missing.
Question, what would be the best/easiest way to replace the donut? Because of the drives haft "mushroom" the donut will not just fall down once unbolted. I am thinking the drive shaft needs to be disconnected from both ends and shimmied forward to let the donut fall off.
That brings back scary memories of a time I had the same thing happen when I was testing a overdrive on a car with the tunnel off while I sat inside the car. All I heard was the bang and the chunk of rubber must have just missed my head before hitting the a-pillar door jam bending the metal a good 90 degrees from its starting point!! There is a lot of inertia with that thing spinning around at 3-6k RPM, thank goodness Ferrari was smart enough to make the center tunnels out of metal.
As for the easiest/fastest fix, you should have a few inches of compression on the driveshaft that will allow you to get the donut out.
Thanks Zac, this was the car's original unit, I'd guess. Chris Coios had a thought that it might have gone in flipped and it couldn't tolerate the opposite rotation.
Are you sure that the gearbox tail shaft can get pushed out a few inches?
That brings back scary memories of a time I had the same thing happen when I was testing a overdrive on a car with the tunnel off while I sat inside the car. All I heard was the bang and the chunk of rubber must have just missed my head before hitting the a-pillar door jam bending the metal a good 90 degrees from its starting point!! There is a lot of inertia with that thing spinning around at 3-6k RPM, thank goodness Ferrari was smart enough to make the center tunnels out of metal.
As for the easiest/fastest fix, you should have a few inches of compression on the driveshaft that will allow you to get the donut out.
Zac
Zac,
than it had the front donut configuration like below
There is always a reason why things were changed.
as I sad before:
"the cotten pin heads should compleetly disappear in the groove of the big castle nuts,
there is extremly few space between these nuts and the nuts of the flange of the rear axle."
This is her most likely explanation not a worn donut or turning otherway around.
its formly cut out after sudden blockage
John Vardanian wrote:Thanks Zac, this was the car's original unit, I'd guess. Chris Coios had a thought that it might have gone in flipped and it couldn't tolerate the opposite rotation.
Are you sure that the gearbox tail shaft can get pushed out a few inches?
john
Hi John,
There's a splined shaft on the driveshaft that allows the shaft to lengthen when the angle of the rear axle changes from the transmission. That may provide enough movement to clear the socket.
I have a PF Coupe at the shop, and will try to take a look at it today to see if I can see what you're up against.
That brings back scary memories of a time I had the same thing happen when I was testing a overdrive on a car with the tunnel off while I sat inside the car. All I heard was the bang and the chunk of rubber must have just missed my head before hitting the a-pillar door jam bending the metal a good 90 degrees from its starting point!! There is a lot of inertia with that thing spinning around at 3-6k RPM, thank goodness Ferrari was smart enough to make the center tunnels out of metal.
As for the easiest/fastest fix, you should have a few inches of compression on the driveshaft that will allow you to get the donut out.
Zac
Hi Zac,
I drove my car like that when I was trying to diagnose the overdrive with the guibo joint spinning next to my right elbow.I gingerly drove the car scared to death, and Francois looked at me like I was a wimp!
It looks kike this had been a week point to the design and the changed to the universal joint at this spot at the 330 series 2. This joint needs to equalize the angle with every rotation and in addition it receives shocks from the axle. The front robber donot at least is free of shocks. May be the angle deviation also is harsher for the rear donat.
An other point I am just thinking: If to much grease is pumped in the area of the splined shaft and you hit a heavy bump first time during tryout it is unlikely that all the grease is squeezed out in the moment of the bump. So your rubber donat will receive an additional hit by the bump when the shaft should contract. Just an idea!
I just also have my shaft on the workbench and have not seen a big orifice where overvolume of grease could go out immediatly when shaft contracts. Spline also sealed by an O-ring at end of brass bush. I had to hammer (by rubber hammer) the shaft to the shortest position according to the surface where it was in the shortest position to get overvolume of grease out.
