Driveline Shudder
 

Does anyone else hear and feel a shudder when taking off from a complete stop? The previous owner said that the dealership swapped several parts and made multiple attempts to repair, but the warranty ran out before the problem was solved.

I was assured that it is a common thing for the S90 and that it is not going to cause a driveline failure.

Any one else???
Mac

It is a very common problem.
One thing you can try is adjusting the center support bearing. You can adjust the big plate lower towards the ground. Or shim the center part closer to the body.
You can use washers as shims.

Warranty ran out??? Not sure why a warranty would be on a 10 year old car but if it was, you can't stop fixing something that was identified while the warranty was valid. If my TV breaks during the warranty period, the the TV repair guy starts repairs, that problem will be fixed under the cost of the warranty.

I hear what you're saying about how a problem existing during the warranty period should be covered until it is fixed. It is an old car and I am not the original owner. From what Tech said it sounds like this noise is caused by the motor or tranny mounts sagging. Makes sense, and makes it a wear and tear issue.

This weekend I will have the old S90 on a lift to replace the swaybar bushings and drop-links that arrived in the mail today. While in the air, I can throw some washers on top of the carrier bearing to see if it fixes the problem. I'll post the results...

Mac

So, I got the S90 in the air and there were already 2 washers installed. So I installed one more at each bolt hoping that it would fix the problem. I think it actualy made it worse. It looks like my next purchase will be a new carrier bearing. :-(

-Mac

Try removing 2 of them and see if it gets better.

Removed washers from the shaft support, and it did help a little. The good news is that I think I found the cause of this vibration. The drive shaft has been installed off by one spline. I was not able to re-align because I didn't have the tools and I was laying on the ground. I hope to get it on a lift this weekend.

Question: Do I have to replace the shaft bearing when I replace the shaft support?

Mac

I am not 100% I think so though. I think you could only replace the rubber on the older cars.
I believe on the 960 there is a allen set screw you need to remove to get the driveshafts apart.

It's confirmed, to get the shaft support bushing off you have to press the bearing off. I had the shaft out yesterday, and had to put it back in with the old bushing still attached. I didn't want to rip up the old bearing to install my new support bushing without having a replacement bearing on-hand.

I did get the slip yoke moved to the correct spline, but it kicked my but for hours... The female shaft splines had one open (missing) spline, which allowed one of the male (slip yoke) spline crevices to become filled with junk. When I moved everything over one spline the two shaft pieces bound up and gave me fits trying to separate them.

95% better than before, but I still feel a hint of a driveline shudder at take-off.

Mac

Glad it is getting better. Did it have the set screw in it?

No set screw. Seemed to slip apart easily. The only thing that provided any resistance to separating the 2 sections was the dust boot.

The real pain will be getting the shaft bearing off without messing up the thin metal cup on the forward end of the support bushing. I figure that I will soak it with some penatrating oil before I put it in a vice and go to town. 1st I have to get the new bearing... Give it a week.

Thanks Tech,
Mac

Your welcome.
If you can find a press and a bearing seperator then it might come apart pretty easy.
I rarely even dent the metal cup doing it that way.

Alot of people do not care about the cup and use an air chisel to push the bearing off.

Finally got around to pressing on a new shaft support bearing and bushing. It was not as difficult as I originally thought it would be. I had a relative easy time with it only because I had access to a press. The bushing made a difference, but did not eliminate the driveline shudder completely.

Now I think I need to play around with spacers untill I get the alignment right. The real question is will this vibration ever go away completely???

Yes it will if you find the sweet spot.