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