08 XC70 Bucking Bronco

replicapro · Post by **replicapro** » 27 Jul 2014, 09:20

Big trouble with my 2008 XC70- 128,000 mi total. Drove 1500 highway mi in the last two days after replacing two front tires, Replacing all four struts, and getting 4w alignment.
In the last 200 mi strange vibration started in front on acceleration then grew worse and traveled to feel like it is coming from under the middle console between front seats.Feels like a bucking bronco when the pedal's down, then disappears when I lift.
Obviously, I am thinking Halex and know the cautions about different sized tires.
I thought the new generation of AWD could handle a tiny change between slightly worn rears and new fronts. Tires are all Pirelli p-Zeros. Temps have been hot here in the NE (80-90F)
Any ideas what could cause this, or even better, fix it?

replicapro · Post by **replicapro** » 27 Jul 2014, 12:55

More info on this: I had a chance to look under the car this morning and nothing is obviously bad there.
Both front axles seem solid with no play. The prop shaft has about 2mm play but nothing leaking or worn at either end. No burning smells at any time. I did get a check engine light after replacing the tires, 1500mi. ago, but it went away after three start cycles. Vibration is like a really rough corduroy road under load, then smooth as silk when I lift. My guess now is perhaps engine mounts? Anyone?

midniteliquid · Post by **midniteliquid** » 02 Aug 2014, 08:27

Are the tires the same on the front as they are on the back with the exception being the fronts are newer?

replicapro · Post by **replicapro** » 12 Aug 2014, 09:47

Update on the Volvo Bronco: Rear main driveshaft removed. Problem gone. Now to decide if I want to spend a ridiculous $1200 for a discounted new shaft from Volvo before the snow flies. Erie VoVo also has used for $675. probably where I am headed.
Thanks for the help

Post by **JDS60R** » 12 Aug 2014, 12:30

Its usually just dry grease on the end cv joints of the center shaft(usually the front one) . You can repack them with quality synthetic grease and inspect for damage, or just buy new ends.

If your boots are ripped here is an affordable source.
http://www.driveshaftparts.com/cv-joints-shafts/volvo/

Post by **precopster** » 12 Aug 2014, 15:32

That's a great resource JDSR60!!
Who thought you could buy CV parts separately like that!!