I think there is a shaft extension on the transmission that engages a
bushing in the driveshaft to assure proper alignment of the driveshaft
regardless of the condition of the guibo. I suppose the bushing could be
damaged but I haven't seen that happen. Psycho, could you try to explain
what you mean by hop type vibration? At what speeds is it apparent? Is
there any accompanying noise?
I had an experience on my 318i where it developed a vibration that seemed
to be at the same frequency as the drive shaft rotation. It was most
pronounced at about 35 mph where the car 'sounded like a pickup truck with
snow tires on it'. After removing the drive shaft and finding nothing wrong
I discovered the problem to be a front wheel bearing. The balls rolling
over the dent in the inner race just happened to be at the same frequency as
the drive shaft and the impulse was resonating with the coil spring
producing quite a loud noise.
Anyway good luck finding it.
Jack
"Fred W" > wrote in message
...
> Psycho wrote:
>> My son's 87 325is has developed an issue and I'm hoping for some
>> solid advice on where to look. I'll be putting it up on a lift
>> tomorrow and hope I can find the problem but I'm looking for advice
>> here. The car has developed what I can only describe as a hop type
>> vibration in the drivetrain. I can compare it to a u-joint vibration
>> but it's more intense. Things I'll be looking at tomorrow are the
>> guibo's and the axle half shafts. I know they have a CV joint in them
>> but I've never seen one do this. I also have a jingling coming from
>> the front tire but since the ABS light came on today I think the ABS
>> ring has come off the hub. I've heard people talk about this...
>> Thanks...
>
> I think you will find it is the guibo. When that goes it can cause a
> large offset in the driveline. It might also be one of the U joints, but
> not likely the center joint as that would just cause the floor of the car
> to shake. I'm sure it will be obvious when you start poking around...
>
> --
> -Fred W