Results 1 to 8 of 8
  1. #1
    Join Date
    Mar 2013
    Location
    New England
    Posts
    3

    Default Volvo Engineers Stumped - New Forum Member with 2008 XC70 Vibration Issues

    First off, new to the XC forum, but looks like a lot of great stuff, and hopefully someone can help me out....volvo's engineers are stumped

    My wife has a 2008 XC70 that we bought brand new. At 10,000 miles the vehicle started having a vibration throughout the whole car (appeared less front end, more rear end problem). We attempted to chase it with the selling dealer (only one in local area) and never got anywhere. The issue was blamed on our tires, and I wasnt putting new tires on the vehicle when it was still brand new. Dealer wasnt helpful and I gave up - would add the vibration concern to the issue list at every oil change, but nothing was done about it. Now fastforward - the vehicle has 65,000 miles, new tires, and the vibration still exists (its bad enough I will not drive the car long distances as I cant stand it - and the car was bought as our family roadtrip vehicle). The selling dealer was acquired by another line of dealerships which is known for extrodinary service. So, at the next oil change I asked for the issue to be looked at. Immediately, the service advisor agreed there was a problem, and the issue came to who would be responsbile for the diagnostic charges - the extended warranty unfortunately isnt a Volvo warranty and thus doest cover diag. Upon looking at the service records, apparently the only good thing the old dealer did was document that the vehicle had a valid vibration concern starting at 10k...so thankfully Volvo has stepped up on the diag costs. Thats the background....(sorry for the long post)

    The vehicle has been in the shop going on 5 weeks now, and they have 60+ hours into diag and we arent making progress. The regional volvo engineer has been leading the diag personally, and has spent 3 days in the shop with the vehicle and driven it many times....

    The issue:
    Whole car vibrates/shakes at 50+ mph

    Whats been done (all Remove/Replace items come off another vehcile that was proven to not have issue):

    1. Rule out wheel/tire issue - vehicle has brand new wheels/tires on it that were proven good on another vehicle for all further diag concerns
    2. Check all fluids in drivetrain
    3. Shut off engine at speed
    3. Check body/engine mounts - found both rear body mounts cracked in half. Replaced. Issue not resolved
    4. Remove Driveshaft
    5. Remove/replace front axles
    6. Untorque/Retorque all suspension components
    7. Remove/Replace Rear AOC (explained as secondary transfer case in rear of vehicle)
    8. Remove Rear Axles - Drive car in 2wd only, nothing spinning from TCase back
    **Issue was thought to be resolved after first testdrive with no rear axles, meaning either a rear axle or rear diff issue. I was asked to come drive/confirm with nothing in the rear end spinning, and halfway thru the testdrive with the service manager the vibration came back and didnt go away.

    They have put 100s of miles on the car test driving with various parts combinations, and the following additional observations have been made:
    1. When the car is driven immediately after coming off the lift, before the suspension completely compresses, the vibration is gone
    2. A slight grinding noise is developing in the vacinity of the gas pedel in certain infrequent situations.
    3. Any brakes/bearing issues have been ruled out since the vibration hasnt changed and nothing has broken in 50k miles.

    One of the tech's apparently is leaning toward the tranny, but the shifts are all smooth and there is no apparent issue there. Im a 4wd truck type guy, not an AWD guy, so all these extra components to introduce slip are new to me. After digging thru the info on this forum, it sounds like we should be investigating the Bevel Gear (especially on account of the slight grinding noise now developing).

    Can someone post a diagram of the entire AWD system layout in the car? The way I understand the layout, power from the engine is transfered to the transmission, then the bevel gear, then the tcase, then to the front diff and the rear driveshaft which couples to the AOC then the rear diff. The service manager hasnt mentioned the bevel gear and struggles to explain the power transfer in terms of components from the engine to the road....

    Can anyone shed some light on this issue? Volvo and the dealer have been great, but we are all frustrated and looking for a solution. And yes, buying back the car has been brought up, but I own it outright and hate to take on a new payment as they arent handing me the keys to a new car....

    Thanks for reading this long post.

  2. #2
    Join Date
    Apr 2003
    Location
    Devon PA
    Posts
    11,409

    Default

    It's possible it's in the tranny but it's a long shot.
    Are you located on the East Coast?

    I had the same issue in a very early 98XC, (May 1997 build, delivered late June 1997) but I'll get back to that in a minute.

    There is an engineer at VCNA who used to be out factory rep in the 90s. A very bright guy named Chris (I will leave his last name out of this for now).
    Anyhow, the dealer started doing the same with mine, first tires, then other parts, nothing worked, then Chris got involved.
    (This was right when new, not at 10K miles).
    Chris and I became close and he really wanted to fix this because I had one of the first 98s back then and he feared the problem would be on other XC that were in the pipeline.
    He asked me would I mind a tradeoff for maybe a bit more noise when I hit a bump for a smoother ride.
    I said go ahead.
    He said he would be back in a week.
    A week later he came back. I dropped the car off and when I picked it up the next day the vibrations were gone and it really was not particularly any louder!!
    He designed and made a pair of billet subframe bushings, he said he thought (correctly) that the ones on the car were allowing vibrations to transmit throughout the car.

    Now, yours is a 2008, an early car with a new chassis so perhaps yours has a similar issue.
    Personally I would have not let this go, I would have demanded a new car, then and there since they were unable to fix it. Now it's too late on time and mileage.

    After mine was fixed there was an immediate running change and a similar bushing was introduced into the line but with the old sound deadening characteristics
    All emails please use: jrl1194 (at) aol.com

    2007 V70 2.5T White/Oak, 112K miles. My daily driver and GORGEOUS
    2000 V70R wife's. Won't sell, now at 148K miles !! and still (almost) perfect.
    2000 S70 GLT SE with 29,000 miles!!! A time capsule, V70R front bumper, Volans, etc. SOLD!!! (I Will regret selling this!)

  3. #3
    Join Date
    Mar 2013
    Location
    New England
    Posts
    3

    Default

    Yes - east coast. Southern Mass.

    I'd been leaning towards bushings/mounts since the beginning, but they feel that the vibration is rotationally generated and in the drivetrain. Right now the vibration is intermitent, as in not present until the car warms up the drivetrain components (3-5 min on highway), and there are two big changes I can see that might effect it, (1) ambient temperature is 10+ degrees higher than its been, and (2) the load on the Tcase should be significantly less (or at least different) as a 2wd car than the full AWD that it has been, meaning it gets to temperature slower.

  4. #4
    Join Date
    May 2010
    Location
    New York & New Jersey
    Posts
    371

    Default

    From your OP:
    The way I understand the layout, power from the engine is transfered to the transmission, then the bevel gear, then the tcase, then to the front diff and the rear driveshaft which couples to the AOC then the rear diff. The service manager hasnt mentioned the bevel gear and struggles to explain the power transfer in terms of components from the engine to the road....

    Engine is a 3.2 liter transverse engine, power is transmitted from crank to trans (front axle half-shafts transmit power to front wheels), from trans to bevel/angle gear which converts transverse rotation to longitudinal rotation to driveshaft/propshaft to AOC (Haldex viscous coupling which normally allows slip, but locks up progressively based on electronic signal of slippage), AOC to rear diff.

    I would be thinking body mounts, angle/bevel gear, unbalanced driveshaft or the transmission.

    While no diagram, I hope this helps.

    Andres
    2013 XC70 T6, Premier Plus, BLIS Black/Black 18K miles, stock
    2004 XC70 Premium, Convenience, Climate Blue/Tan 122K miles, 2007+ ABL lights, IPD sways F & R, TME exhaust, SS brake lines, R Brembo calipers & rotors, Akebono ceramic pads F & R (replaced PCV, power steering rack, struts and springs, end links, ball joints, A-arms, all fluids)

  5. #5
    Join Date
    Jan 2011
    Location
    Fort Worth Texas or thereabouts
    Posts
    400

    Default

    The front wheel drive is direct. The trans directly drives fronts with no possible way to disconnect the front axles. The final drive case in transaxle has a collar that connects the angle gear (bevel gear) and that turns rear driveshaft. The driveshaft turns the input to the Haldex (volvo calls it Active On-demand Coulper, AOC) which has a wet clutch plate set that can be locked or have reduced apply pressure for a less than full torque application to rear differential to drive rear wheels.

    There is a control unit, Differential Electronic Module (DEM) that controls the extent of clutch apply in the AOC. The DEM varies the application based on wheel slip calculations primarily derived in the Brake Control Module (BCM).

    So as I understand the list of things above did not result in the vibration going away.

    Since you effectively had it operating as a FWD XC70 then the AWD components would seem to be off the table though the angle gear might still have been in place. I can't imagine an angle gear caused problem to not have progressed and worsened A LOT in almost 50K miles.

    Is the vibration like a tire balance problem or is it faster/higher frequency? Is it high amplitude like a badly imbalanced tire or a more faintly felt vibration?

  6. #6
    Join Date
    Mar 2013
    Location
    New England
    Posts
    3

    Default

    The vibration is high amplitude, much like a badly balenced tire and can be felt through the whole car, but not the steering wheel. As a passenger watching the dashboard you can visibly see the car shaking. After the most recent test drives, the techs believe it is getting worse as componets get hotter, driving it longer and harder (though they admit not wanting to push the car over 60mph which makes me feel great knowing my family will be riding in this car again if/when they cant find the issue and return it). Gently applying the brakes and maintaining speed (ie. increasing the load/force on the drivetrain) makes it much worse now. A front brake job was done on friday to rule out any rotor balance issues on account of this behavior, and to ensure the vibration is increased due to increased load/force and not braking. The initial test drive shows no difference with the brake job.

    The bevel gear is currently connected, and susposedly being investigated this week, but I dont believe there should be any load on it with no driveshaft in the car, so Im not hopeful on that one.

    It will be interesting to see where we go from here - its not like you just swap in a new transmission real quick to rule that out....

  7. #7
    Join Date
    Nov 2009
    Location
    South Wales UK
    Posts
    1,901

    Default

    Having had something similar but not on a Volvo I would be inclined to be looking at the body/engine mounts.

    It sounds like something has either hardened up or failed so vibrations from movement are being transmitted through the bodyshell which are then being heard and felt through the whole car except the steering wheel which while being a bit strange might be due to the way the connections are made in the steering column.

    It sounds like having a rock hard suspension when you feel every bit of bad road being resonated through the car.

    I hope they find the problem as it sounds like a nightmare!

  8. #8
    Join Date
    Aug 2011
    Location
    Wyoming
    Posts
    74

    Default

    Any updates on this?
    2014 Volvo XC60 T6 AWD Sport: Stock for now
    2009 Scion tC 5M: True Ram-Air with K&N Filter, JVTR Header, Raceland Exhaust with AR25 Resonator, Seibon Carbon Fiber Hood and Hatch, HIDs.
    1998 Olds Cutlass GLS 4A: K&N Short Ram, P&P TB, Custom Exhaust, Enkei MM2 Ultralight 18's.
    1997 Suzuki Sidekick JLX Sport: 3 inch Lift with Long Travel Shocks, larger tires, and Dash mounted CB Radio.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •