Sheared Drive shaft bolts

So theres a creaking noise coming from the footwell, when i back off the throttle, and when turning.  It does happen all the time, but increases as the car gets warmed up. I thought it was the CV joints.  The vibration noise got worse, and I was amused to find that the wheel bolts were lose. TIghtened them, but the noise is still there. Also, there must be enough vibration at the hub to loosen them, as when I went to pull the driveshaft they had slackened.

When I went to undone the driveshaft, I could see that 2 of the bolts that go into the flange are "missing".  Once the driveshaft is out, it appears that both these bolts have sheared off.

After the little story comes the questions.  Has anyone had these shear before, is it normal?  and anyone want to guess whether the vibration and  creaking was caused by those bolts being missing, or did the vibration break the bolts?  Other 4 bolts are fine, the splines are in good nick, as were the CV joints. Ideas?

Ta muchly in advance.

//Rich

I think they can shear because they are too tight.

Never seen one sheared before  8O

I think if they come loose then they are definately more likely to shear. It happened to the drive shaft bolts on the rear axle of my gf's triumph herald. She was lucky not to loose a wheel. her symtoms were knocking/vibration and then no drive!!!  :wink:

Thanks guys, i'll get me hands on some new bolts and drill the old ones out. Fingers crossed that that sorts out the noises and vibration too.

They might be loose so you do not have to drill them

this happened to me the other day and ive been running with only 5 bolts for now and there already coming loose ive ordered 12 new bolts so will replace them all, is there a reccomended torque for these and is it a good idea to use locking compound?

make sure the 3 double washer plates are fitted. shouldnt have to use threadlock, if they keep coming undone replace the bolts. might be the threads on the flanges are buggered also