S/V/C70 AW55-50N transmission solenoid fix

edited July 27 in Articles & Guides

Car done 180000k and owned since new but transmission has been bad for 3 years. Flared shifting and bad clunks and occasionally wheel spins as it finally kicks into gear. Thought I would get lucky and tried the easy fixes like the B4 servo cover and flushing the tranny and resetting adaptation - they seemed to help for a while but with aggressive driving in hilly suburbs always seems to upset it and sets in play a new pattern of bad shifting and the eventual yellow exclamation mark and "service transmission" code on the dash. Just about everyone says replacing those 3 solenoids is the magic bullet so as a last resort before I junked the car I ordered the Rostra Solenoid kit from Ebay - around $200 aud

Various youtube videos , Howards Volvo site & the UK XC70 forum and an aussie guy called Mark from melbourne who said he used the XC forum instructions gave me the confidence to tackle it.

Like Mark I chose to use a floor jack and a large flat timber block instead of a lifting beam to support the engine & gearbox as the subframe needs to be lowered to provide sufficient clearance to manouvere the tranny's valve body cover out of the vehicle. Once thats off you have reasonable access to the solenoids and they would be easy to swap out if it wasn't for the 3 electrical clips which are a bitch of a thing to get out without breaking the original connector on the old solenoid body. Some people have successfully just cleaned out the old ones with drills and fine grit wet and dry paper or used the transgold kit to rebuild them but given the investment in time and effort just to get at the damn things out I chose to put the USA made and redesigned Rostra ones in as the fiddly transgold kit for rebuilding each solenoid is the same price any way. The Rostra ones have their clips upside down for some weird reason but that doesn't cause any issue as there is enough slack in the wires to clip them in.

Job is supposed to take 6 hours - yep maybe for a gun mechanic but not this old guy with his large fat stumpy arthritic fingers and crook legs and neck. Allowing for doing a few extra bits unrelated to the task it took me closer to 20 hours. Most people could comfortably do it in a weekend without rushing. But there is always a bolt or 2 that will drive you nuts - like the one bolt in between the tranny dispstick and the valve body that requires alignment of 2 brackets and took me 3 hours to put back in only to realise I was trying to put in the wrong bolt - DURRRRR! . Proof I've got bolts loose in my head too.

Anyway - was it worth it? Torture tested it today on my hilly streets and so far so good, even on big kick downs . Changes like a car is supposed to. I will do the fluid counter reset and adaptation with VIDA next and see how that goes but I'm already happy with it . I wont really be able to tell how successful it has been until I drive the car up Queen St Mosman as that's the only place where the transmission failure message has ever come on . Not a particularly steep street but its the succession of hilly stop starts and turns in getting to that street that always seems to bring on the failure message.

Stay tuned for further progress.



    edited September 15

    Can report that car is running better than new with the 3 solenoids replaced 3 months ago.

    I also drilled 3 access ports in the valve body cover to enable fine future shift hardness tuning if necessary There is a template for the holes on a website somewhere - if you need the info just txt me and I will find it again. I plugged the ports with rtf and a modified plastic push pin of the volvo wheel arch liner variety.

    I did the oil counter rest and set the adaptation back to default but haven't bothered doing the full on adaptation process. I started the adaptation process but I was using the wrong instructions for the speeds and couldn't get past the first adaptation. When I get around to it I will use the correct instructions I printed off from VIDA

    Used el cheapo Bunnings auto oil - Valvoline multi atf they sell for $35 for 4 litres in the Bunnings Tool shop departement. I only needed 4 litres as I didn't do a flush this time around (didnt need to as i'd done one a year earlier) . The Valvoline meets the 3309 specs and 60% of thee price of the mobil 3309 & 1/7th the price of the genuine volvo fluid which is just rebadged mobil 3309 anyway.

    The roads and odd hills and corners that used to cause the gearbox to jerk are now eaten by the gearbox. Even aggressive standing starts are now possible.

    Thumbs up for the Rostra solenoid kits on ebay!

  • Thanks for sharing your solenoid fix.

    Valvoline Maxlife ATF is seemingly well liked wherever I've read about it, and at $34.99 ($33.24 with powerpass) from Bunnings it's great value for a JWS3309 Full Synthetic fluid. Hopefully these companies don't just print 3309 because they can.

  • Ha! I did even better on the price using my sons old Bunnings staff card to get 20% off. Almost worthwhile getting a casual job with Bunnings - he's only done 1 shift in the past 18 months and still gets the benefits

  • I guess they will close that loophole now the cats out of the bag...….

  • Oh gee, I need a Bunnings job!

    One shift a fortnight please.

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