See below cut/paste from the C70 Forum. As the V70 is mechanically similar I'm posting it here also.

I've been working (on my new to me 2008 C70) on what appears to be a not uncommon drivetrain vibration issue. One previous owner, and I have complete maintenance history.

Intermittent at low speed or under acceleration vibration. Doesn't feel in the steering wheel but in the floor etc. Tires are new, purchased prior to me buying the vehicle. Sometimes, most times smooth as silk especially while cruising. Other times at slow speed access or access to pass it shakes.

So far both right and left axle have been replaced. Left and right engine mounts have been replaced. Two piece transmission torque mount was replaced. Tires balanced yesterday. IPD tower brace installed. Planning to change out the spark plugs next week.

My question is, is there another transmission mount or other mount on the car. Been searching the threads but just haven't found a definitive answer for the later 2007 and up C70's.

Any help on that question? Any other ideas or advise?

Thanks in advance for your kind assistance.

 

I've seen more than a few of these have a failed RH motor mount below the crankshaft pulley. The reason is that you can have oil leaking down the engine on the mount and it rots the rubber.

In about 8/10 times, I find that mount bad when there is a vibration issue.

 

Tony, thanks for the note. All three mounts have now been replaced. RH mount was toast.

 

 

I've only found three, LH, RH and Torque Mount. IF anyone else knows where a fourth might be please let me know.

Changed spark plugs today. Old ones did not look bad, Volvo plugs. I put in 5 knew Volvo plugs (aint cheap) runs better and a little smoother but the jury is still out.

 

The four mounts are the lower torque mount which technically mounts to your transmission, the upper torque mount which mounts to the stabilizing rail under the hood, it's got a circular bushing. The other 2 are the LH and RH engine mounts.

 

Zmarsh,

Thanks for the note. Unfortunately you are incorrect. Earlier C70's did have the upper torque mount but from 2007 to end of production in 2013 that mount was eliminated.

 

Gotcha, they probably only have the 3 then. Call a volvo dealership to verify, though. They should know if anyone. I've never even looked at a c70