I've been experiencing a harsh vibration coming from the rear of the car. Tires and rims are in good shape along with balancing. Just changed the center support bearing and rubber support last weekend, apparently it wasn't the issue. Got my tires balanced and it still shakes. When I roll back into the throttle the vibration goes away almost completely. Panhard rod is OK and the trailing arms are OK. The torque rods had visible play when twisting them but no front to back play. Will be replacing them. My main question is what are the failure symptoms of the panahrd rod and trailing arm? Has anyone else experienced this issue with bad torque rod bushings? Also can feel it shimmey when I accelerate hard from a stop. Thanks for any advice!

-Corbin

Volvo From Heck, I just marked the front half to the transmission, and never touched the rear half shaft, when I put it back together the half shaft and tail shaft were matching and the rear driveshaft wasn't moved at all. Might just take it to a shop and have them find out what's wrong with it. Hopefully the driveshaft is out of phase. Is it possible it's out of phase if the splines didn't match up but the position matched up?

Update: just got off the phone with my dad who help me with the midshaft bearing job. He swears the driveshaft was put in correctly since the vibration was happening before and after I replaced the bearing. Will grease the rear u joint and see if that helps at all. Don't really know what else could be bad if the driveshaft was put in correctly.

Sorry for the confusion, really stressed at the moment as my car isn't really driveable and my girlfriend's car is 100% not driveable. So, when I changed the midshaft bearing I loosened the flange at the transmission and just dropped the center support bracket. After that I marked the bottom of the front half of the driveshaft, as I wasn't dropping the rear half of the drive shaft. I seperated the splines with the rear half just laying on the ground. After that I changed the bearing and rubber support. I also greased the front u joint since it was off of the car. I know it's not really ethical to drop just half of the drive shaft but my dad didn't want to drop the whole driveshaft. Will try and grease the rear u joint Wednesday and go from there. Still ordering one just in case. Hope I cleared things up, sorry for the confusion.

Pageda I just moved the driveshaft up and down and left to right and it moved freely. But you're saying I need to to take the driveshaft off the differential and move the u joint then?

You can remove the bolts and lower the back end of the drive shaft onto a jack stand, then see if the U-joint is free or seized. That way you won't have to separate the DS pieces to check it out.

If it's bad mark the front and rear sections of the DS so it can be aligned correctly on reassembly. Also mark both sides of the yoke so when installing the new U-Joint it will also be correct and as originally balanced.

Dan

Yes, that's what Dan and I said. Holding and swinging the mass of the entire rear section tells you nothing about the condition of the U-joint. You need to hold the shaft and swivel the flanged end--removal from diff required. - Dave

CB- just ordered from FCP. Will arrive on Friday and install on Saturday

Odds are that the rear U-Joint is your problem.
It is the cheapest and the easiest to fix and prove if it is the issue.
Just do it.

The only way to test the rear U-joint is to lower it at the differential and see if it moves freely or is bound up.

I have had 2 rear U-jointes bind up and need replacing.
Dan

I don't quite understand your last two posts. How is it possible to replace the center bearing without separating the two halves? Marking the driveshaft to the transmission accomplishes nothing. It's the relationship of the front section to the rear section that counts. Are they now aligned as I suggested needs to be done? Were they correct to begin with? If the rear section wasn't removed from the differential how could you check for U-joint condition. They more often get tight in one direction or the other (by manipulating the free end through its entire range which requires removing it from the diff) rather than finding play in the joint. - Dave

1989 year. Sorry. When I changed the carrier bearing all of the u joints were solid and no orange dust indicating that they were dry. I did grease the front one because I just took half of the driveshaft out. It sounds like the rear end is vibrating at any speed so I'm stumped on what it could be. Thanks for the advice!

Driveshaft could be out of phase.

Did you mark it?


--
'80 DL 2 door, '89 DL Wagon, '15 XC70 T6

Corn98, I read your last post in the middle of the night--and had the same thought as Bulletproof. If you were not aware - there are two things that have to be correct with a two piece driveshaft -- phase and balance. I explain "phase" this way for a 2 piece driveshaft. Imagine the yoke attached to the transmission and the yoke attached to the differential as one complete U-joint. In other words - each at 90 degrees to one another. The rear section then has two possibilities - only one of which will be correct for "balance". Thus the importance of marking the halves (assuming they are correct to begin with) unless you like doing jobs twice. Your symptoms are exactly how a driveshaft would act if "out of phase". A driveshaft "in phase" but not aligned for balance will likely shake at certain speed ranges. -- Dave

You didn't mention the year. If it isn't the latest 240 with a bearing for the auto transmission tailshaft, a worn bushing will cause shake on take off. - Dave

Worn panhard rod bushings will cause the rear axle to be offset. Worn TAB's will clunk and cause a rough ride. Worn torque rod bushings will cause the rear axle to hop on take off.

A bad rear u-joint can make the car shake to beat hell.


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'80 DL 2 door, '89 DL Wagon, '15 XC70 T6

Based on symptom descriptions, bad ujoint was my thought as well. The bushing mess usually just results in clunks and bangs.
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82 242-6.2L; '17 Mazda3; '16 Crosstrek

Check your exhaust mounts and see if any are missing and/ or broken. rear shocks ??
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