Ongoing V70R Vibration / R specialist in the north?

[rockinron]

Hi all,

I have a 99 v70r AWD (phase 2, 4 speed auto, 2319cc engine).

Unfortunately since buying it has had a vibration that I've never been able to diagnose. It's such a shame because other than this the car is absolutely spot on.

The following is what has been done:

New alloys + tyres + balancing
Wheel Alignment
CV Axels reconditioned
Propshaft reconditioned (twice)
Propshaft centre bearing changed

But the problem still persists.

I have given up hope on any local garage being able to diagnose it so looking for suggestions on any Volvo AWD / R specialists vaguely near Yorkshire?

The vibration starts around 50mph and gets worse up to about 70 and is very much in the middle / back of the car, beyond that it seems to smooth out a little but stays present.

When the prop shaft is removed from the car the vibration stops completely and car runs perfect.

This has lead to me having the prop shaft balanced (even though there's an invoice from the previous owner for it doing), so the prop shaft has been balanced twice and that's not the problem.

2 different Volvo independents have looked at the car and the only niggle one found was a very slight bend in the short driveshaft in the middle of the CV axel. However with the prop shaft removed the vibration goes so in theory it shouldn't be this.

I'm thinking it's maybe the angle gear or viscous coupling but having read around online I'm not sure which and it's a bit advanced for my skills. Furthermore apparently a new VC would need lining up and balancing and I'm completely lost at that point - RWD is not something I've had before.

Any ideas or mechanic recommendations welcome.

[capt jack]

Would very highly recommend talking with Paul Dyrdal at Dyrdals, Hospital Fields Road, Fulford, York. 01904 633809.

[rockinron]

Thanks for the message.

It's actually Paul that spotted the slight bend in the CV joint. Very impressed and been back with my XC90 since but he's just not sure on where the problem is on the V70R. Also tricky with it being 20 year old it's not like they're working on them on a daily basis anymore.

At this point it may be that I just try to find a donor that's being broken and change the major parts till I find it... Hopeful there may be some R pro out there that can diagnose it first though.

[DSK]

Is it just a vibration or is there any associated knocking that comes and goes with the vibration over bumps etc?

[huron]

Know nothing about this model but on a Land Rover I've had a similar vibration where someone had got the CV joint at each end of the propshaft in the wrong alignment to each other.

[rockinron]

No knocking purely speed related and direction / incline doesn't seem to make any difference. The car drives perfect otherwise.

I'm starting to think it may be related to the viscous coupling.

If it was the CV I'd assume it would continue with the prop shaft out which it doesn't, although maybe that's related to it being under load or not.

[byootox]

I assume the bushes on the rear diff are in good order and no excessive movement is present ?
The cv joints on either end of the the propshaft... have they been inspected ? they can get dried out.

[ASt85]

Originally Posted by rockinron

2 different Volvo independents have looked at the car and the only niggle one found was a very slight bend in the short driveshaft in the middle of the CV axel. However with the prop shaft removed the vibration goes so in theory it shouldn't be this.

Have I misread this, as it would seem that if the bent driveshaft is removed the vibration goes away - doesn't that mean the bend is the issue?

A bent driveshaft will cause vibrations which get progressively worse as the speed increases, it can lead to excessive wear in the bearings/CV joints at either or both ends of the shaft which then exaggerates. A bend in a shaft is very difficult to correct by balancing as the loads at the bearings/cv joint are still acting out of alignment.

[rockinron]

Ah no, sorry I mean the prop shaft has been removed but the half shafts left in place. When driven like that the vibration goes away so that would seem to point to it not being the slight bend that's in the half shaft. The exception being if its happening only when the prop shaft is reconnected and the half shaft under load but there's no change in feel with changing acceleration.

I would typically just change the half shaft and see but it's a pain of a job on the R and not going to be cheap nor easy to source.

The prop shaft has been balanced and setup so it's not that, centre bearing has been changed. I can't see how it can be anything other than the VC or diff but finding a tech who knows theses cars is proving tricky.

[mankypaws]

What wheels have you put on the car are they genuine Volvo I've seen after market wheels with larger centre bore fitted without a spigot ring so the wheels not central on the hub