At the end of January I started experiencing a weird vibration from the transmission, only when slowing down, off the accelerator, between 40mph and 10 mph. The vibration happened even if the clutch was depressed or the gearbox was in neutral.
Over a week or so the vibration got worse until something had to be done.
Everything I read, on this forum's FAQ and fronm other sources, associated the symptoms with faulty propshaft components, especially the centre support bearing and guide.
The bearing and guide from Volvo would have been around £200 but I found them for £53 from Parts For Volvos, delivered next day.
Getting the propshaft off the car was hard. Access to a lift or ramps would have made it easy but I only had a couple of axle stands and jacks so there was a lot of swearing and skinning of body parts.
The bearing was ok but the guide was badly rusted and the rubber perished. As I was replacing both I pulled the guide away and carefully cut the bearing off with an angle grinder with a fine (1mm) metal cutting disc.
I used a suitable sized sleeve to drift the new bearing onto the shaft and then the guide onto the bearing.
Re-fitting the propshaft was once again a mixture of swearing and self harm.
Unfortunately the new bearing and guide made little difference, just reducing the amplitude of the vibrations slightly.
I then spent two weeks trying to work out a solution.
The rubber front coupling was in good condition so my thoughts drifted to replacing the universal joints on the rear section of the propshaft. If that failed the next step would be a new propshaft.
I found a video on replacing universal joints (didn't look too difficult
https://www.youtube.com/watch?v=rOEdul7nscY) and ordered some.
The universal joints cost £16 (ebay) and came this morning.
Fitting the new joints went well, mostly following the hammer method from the linked video.
The front u-joint was ok but on the rear, one of the bearings was seized:
I'm surprised I didn't notice the lack of movement in the rear u-joint when it first came off the car, but as most of my attention was taken by the other section with the bearing and carrier it obviously was missed.
I made sure that the new joints were packed with grease to stop this happening again.
A quick test drive confirmed that I had finally cured the vibration and I can now find something else to worry about.....
Cheers
I have attached a pdf of the propshaft parts list for the late model 940s. It might help others in the same situation.