Now available in any qty from Born Built Beauties; the prop shaft bolts (3293921-C) for the 340 MT and 360 prop shaft.

The bolts come with installation instructions and are "single use" items.
I know that these are a problem as Volvo hasn't had them for a long time.
Just send me a PM for more details.

As used on the 360.

As used on the 340 MT.

Are these not available from any nuts&bolts suppliers:

M8x40mm Grade 12.9

Pretty much all hex socket bolts are 12.9 these days.

http://www.namrick.co.uk/acatalog/Metri ... lour_.html
http://www.fixingsupplies.co.uk/sockets ... p-s-c.html

I notice the threads are quite long on these, compared with my original one, do we need the shorter threaded version?

commonly available yes, but here in holland you can only get them in boxes of 100 or 200 pieces, or 2 bolts cheap and added €15 handling + postage costs.. that's why they got available on this route.
the thread length isn't important, what is that these get replaced on all 360's cause the bolts that overstretch due to aging cause the connecting piece of torquetube > gearbox to fail.

Hmm, can't this be counteracted by doing up the bolts tighter?

You think it's worth getting some for my 90k miles car?

Its is a highly engineered part compared to the rest of the car (outside the gearbox and engine). Its one of the few 12.9 grade parts. Definitely needs to be kept within the designers intentions. I know the 340 ones come off if they are over or under torqued.