Vibrations when on higher speed and when car is accelerating

Jagger · Post by **Jagger** » 27 Mar 2012, 04:51

Hi everybody,

I have a 2001 V70 T5 and experiencing vibrations when the car is on approx. 110km/h speed (~68mph) and under load, i.e accelerating. If I go off the throttle, the vibrations are gone.
I have replaced the engine mountings, which in fact, were very worn but even after that, the vibrations are still there.
Especially when the car is accelerating and I'm going through a "dip", I can feel the vibrations.
I think I can rule out the tyres as the vibrations disappear when going off the throttle, which should not have any influence if the tyres would cause the problem.
It feels as if something is imbalanced, especially at about 110-120km/h or when going through a dip and while accelerating.

Has anyone experienced something like that and what could it be?

Thanks,
Norbert

Post by **fazool** » 27 Mar 2012, 06:21

You need to separate the engine speeds from the road/tire speed to see if the vibration follows road speed or engine speed.

When you are at 110-120km/h, what is your engine RPM speed? Find that number what is the RPM when it is vibrating.

Now, can you use a lower gear and get the same vibration at the same engine speed but at a ;lower road speed?

For example:

If in 5th gear, 110km/h and 2400 RPM you have vibration now try 3rd gear, 60km/hr and 2400 rpm.....do you still have vibration.

If yes, then the vibration is engine speed related. If no, then it is driveline/wheel related.

Can you get the vibration to occur and can you hold the engine and/or road speed to keep the vibration happening or does it always go away.

volvodoc · Post by **volvodoc** » 27 Mar 2012, 07:52

replace the right drive axle

Post by **chrism** » 27 Mar 2012, 12:20

Jagger,

I would second Volvodoc's diagnosis. My car did EXACTLY what you are experiencing. Also, when turning left and accelerating at the same time, I could feel a definate lump-lump-lump in the the right front.

Rather than purchase a Volvo-supplied axle ($400+) or a questionable Chinese unit from the local parts house (approx $100), I rolled the dice and took a shot at swapping out for a rebuilt Volvo axle from Axles Unlimited in North Carolinas (about $125-150 as I recall, plus a rebuildable core which yours should be). I asked them what "rebuilding" meant. He said they pull them apart, grind the little channels out a small amount, and reassemble with oversize balls, grease pack, and new boots. I questioned the wisdom of grinding out the channels and the possibility of cutting through the surface hardening. In their opinion, if you don't remove more than about .030, then you will not have compromised the heat treating. I considered this option to be no more risk than the Chinese axle, as the OEM is built by GKN which is a reputable manufacturer - but that's just my opinion.

Jagger · Post by **Jagger** » 28 Mar 2012, 05:37

Thanks to all of you!
I wish I had asked for advice earlier. Yesterday I took the car to a technician who was recommended to me.
He said he reckons the problem is in the driveshaft but in order to make sure he has to take it out.
Therefore he had taken them (both sides) out yesterday and already sent them for "re-conditioning".
I can fetch the car this afternoon, an equivalent of $525 later (lighter). I'm not sure yet what the re-conditioning entails,
but I will ask when I get there.

The problem I have is that I'm going on a long trip next week and I was panicking a bit.

I just hope that it actually helped.

Best regards,
Jagger

tardis007 · Post by **tardis007** » 10 Jan 2013, 17:31

Did It fix your problem?