2000 V70 XC Short bursts of washboard vibration (failed centre bearing)

aewoodhouse · Post by **aewoodhouse** » 06 Feb 2017, 15:18

I recently parted with my very dependable 98 S70 base 5 speed of 10 years in favor of an automatic 2000 V70 XC SE with a mere 67,000 miles on it.

Everything seemed to be perfect until I noticed that on the highway, only when going over 60 MPH there are occasional, short, one second bursts of "washboard" sensation/sound coming from the rear. I have been googling all afternoon to no avail and wondering if anyone has any wisdom to lend.

Further details: It is most often triggered by a lane change or acceleration, never lasts for more than a second, and is a lot like when you drive over the warning grooves put in some highways to warn of drifting into the shoulder or similar. I tested obsessively today and yes, I am certain its coming from the car, not the highway. All four tires are the same Pirelli P6 but the two rear ones are new and the front ones have 50% tread with significant dry rot. I know I am in for some new tires (just picked the car up yesterday) but started to worry that this could have more to do with the costly drive shaft. Its my first AWD car so forgive me if the obvious answer is the tires. I was just unable to find anything out there that fit this description.

Thanks for any insights!

Post by **wizechatmgr** » 06 Feb 2017, 15:28

AWD? Wondering if differential could be involved.

Post by **FlyingVolvo** » 06 Feb 2017, 16:08

Man, that thing must have lived in a garage for 17 years! Mine of the same year has nearly 200K more!

If this is happening very reliably... the first thing I would do is remove the main driveshaft for a while. If nothing happens, then you've narrowed it down to the AWD system (I'm betting on that). Just FYI, the AWD systems on the 98-2000 cars are finicky and generally very expensive to fix at most shops. I converted mine to FWD by removing the angle gear and drive shaft. Hopefully yours is still "new" enough to avoid major work, but even 67,000 miles is enough to shred these systems if they've been abused.

The only other thing I can think of that might make a racket back there could be failing parking brake shoes.

Post by **850 LPT** » 07 Feb 2017, 05:35

Congrats on your purchase! Was this car for sale in Scarsdale? I was eying that.

Anyway, you will want to replace the front tires really soon, your angle gear will thank you for it and last longer. To have the same exact tire diameter on all fours is critical in these cars.
I would also suggest replacing the angle gear oil soon. If it has not been changed it's too old by now.

Good luck with it,

Dirk

Post by **abscate** » 07 Feb 2017, 06:46

If it was in Scarsdale it was probably only used monthly for trips to the local cosmetic surgeon.

Definitely try two new matched tires on back first, or swap them front/back and see if it changes?

Post by **rspi** » 07 Feb 2017, 07:07

Stop driving IMMEDIATELY. Different size tires will DESTROY the AWD system in these cars in less than 50 miles. READ the owners manual. Ask me how I know.

aewoodhouse · Post by **aewoodhouse** » 07 Feb 2017, 07:41

Thanks for the replies! Yes, Dirk, it was indeed the one in Scarsdale. An amazing find with such low milage and in very good shape. I will definitely start with the tires, If it persists, then based on what I've read about failing driveshafts, seems like it can't be too far gone as these short bursts only happen under very specific circumstances. That is my hope anyway. Its nice to know that regardless, I can always revert to 2WD though the feel of the AWD is a pleasure to drive.

Post by **rspi** » 07 Feb 2017, 08:06

abscate wrote:If it was in Scarsdale it was probably only used monthly for trips to the local cosmetic surgeon.

Not sure if this is funny or sad. I know 2 people that live in Scarsdale, both have gotten cosmetic surgery multiple times in the past 2 years. SMH

Post by **850 LPT** » 07 Feb 2017, 10:40

I think it's funny. Typical abscate humor, what can I say.

Post by **scot850** » 07 Feb 2017, 11:13

Read what rspi says about the tires. Volvo P80 models are particularly sensitive to tires with different levels of wear. Replace the 2 worn ones immediately or bang goes the AWD system very quickly. Read the warning in the hand book!

The vibration is possibly de-laminated rear parking brake shoes. Check those first. If they are good, then remove the prop-shaft. This does not identify the fault other than there is a problem with the AWD and one or more of the components.

Also check the brake calipers. The rears are more prone to seizing.

Neil.