Hi Martin,

"Is the break quite "clean" and pretty much in one plane, at right angles to the axis of the shaft? If so, this particular fracture is almost always a metal fatigue problem, and I'll bet your gearbox is just fine."

Sounds about right, the break is clean.
So clean in fact that its hard to see even with the engine running and central axle spinning, i guess metal fatigue is not to far fetched for a car thats 31 years old.

Thanks for the input.

 

I was thinking about JB's comments this morning bringing in the horses and I got back to read his followup comment, and his point is correct. I focused on "it happens" Mr Bailey was thinking what I should have been thinking about, "why?" It could have been age and a stress riser that finally let go, and it could have been caused by misalignment or vibration, so you should indeed consider those things as well. Any problems like that before it happened might point you in the right direction.

 

Hi martin,

I think the following may have happened:

As i drove the car home from the shop it was running very rough (not running on all cilinders) and i think this caused extra stress on the flange that may all ready have been weakened by metal fatigue or a possible trashing it may have received from the guy's at the shop (they don't usually see a porsche there). This is just a hunch ofcourse but because the timing belt turned out to be way off as well and the car was running perfectly when i dropped it off there, it seems quite plausible.

 

Robu-> You may want to invest in Porken's Lift Bars. They assist in supporting the car on jackstands.

 

Rough running missing fourcylinders is cause for broken driveshafts according to Porsche service bulletin. That tends to happen to automatic trans 1985 > when one of the two coils /ignition fails. Any piece of metal can have internal flaws which weaken it and allow it to break when stressed but with in the original design parameters. It is far more common to see the driveshaft break rather than that input shaft but anything is possible.

 

Yep, seem like a good investment, thanks for tip.

 

Hi James,

I agree with what you're saying but to be honest i'm just glad it seems not to be the driveshaft.

I will however be re-checking my findings just to be sure since, besides you, others also indicated it to be such an unlikely thing to happen.

Thanks for explaining.

(and please forgive my, not so good, English)

 

Hi Guy's,

It doesn't look like i'm able to do it my self any time soon and if i would have the time i'm still not 100% sure i'll be able to do it in my garage so the car is going to a Porsche specialist next week.
They gave me an estimate of 825 euro's to fix it including labour and tax (for dutch standards a pretty good price).
I've had the car now for 1/2 a year and i guess it's about time i get to drive it again.
I'll let you know what happens.