S/V/C70 AW55-50/51SN Geartronic Transmission trouble

Did the B4 servo, did the flush and thought i'd solved the flared and thumping gear changes at low speeds only to have trouble back with a vengeance.
In fact it occurs almost without fail when I reapply the throttle to exit roundabouts.
So what to do?
Change the valve body with a $200 ebay one?
Change the solenoids with the $130 kits on ebay?
Change thes solenoids with genuine Rostra ones for $300?
Pull the solenoids apart and clean them - $ zero cost
And accept that even if i do these things it probably has worn clutch plates anyway?

Has anyone had any success fixing or prolonging the life of these trannies by swapping out the valve bodies or solenoids?


  • How could the maf sensor affect gear changes? read that somewhere......
  • You used vida to reset adaption post these changes?
  • no, was going to but some said not necessary
  • no, was going to but some said not necessary

    I'd do that before anything else
  • ok. will do. diagnostic tabs not working on my vida laptop; have been futzing with reinstalling it and lost sleep 3 nights running.
    edited May 2019
    Finally got diagnostics working OK again with a fresh install on a fresh copy of xp3 pro on an old cf18 toughbook.
    Although it doesnt meet specs as its only got 1.5gb max memory & only a 1.2ghz 59gmhz processor.
    Got it to run by over-writing the installation config.
    At this stage just reset the oil counter and will see how it goes before doing the adaptation sequence.
    No codes have ever been thrown but I will place it in "test" mode which heightens its fault sensitivity and take it for a spin after oil temp reaches spec to see what faults can be found.

  • Got Gearbox Solutions (Moorebank NSW) to overhaul my AW55/50 valve body with Sonnax kit and this fixed rough changes. Known issue with Volvo solenoids etc in valve bodies and software updates will not fix it.
    Also replaced all ATF fluid with Redline D4 Full Synthetic from Rocket Industries (Huntingwood NSW)
    This worked for my XC70 and I do not have any business association with these companies.
  • Thanks Tesla777!
    Was going well for last month since I reset the oil counter . Thought it had fixed itself but yesterday played up really bad .
    Odd thing is that seems to get triggered in roundabouts!!!
    Any theories there???
  • Boxy , that is the same fault I used to get ie occasionally a really rough gear change coming out of a roundabout.
    Sonnax valve body kit fixed it , has to be correct kit as Volvo made running changes to solenoids etc
    First try was a full replacement of ATF (as most owners don't change it) and then finally put in Redline D4 ATF synthetic fluid as forums mentioned this was best for AW55/50 (Aisin ie Toyota 5 speed)
    If you want to save yourself time and $$$ , my car is for sale on this site 2005 XC70 located in St Marys with rego til April 2020
  • After Valve body change , the computer then takes about 1000 km to relearn your driving patterns.
    Dealers will rip you off (Valve body costs about $3k) and very few Auto Transmission shops know how to fix it
    Gearbox Solutions (Moorebank NSW) fixed my Valve body
  • I've had my car since new. Paid almost 90K for it back in 2002!
    I will keep it alive as long as I possibly can .
    How much did tranny repair cost?
  • Thanks. Makes it hard to justify 1800 when car is probably only worth 2 to 3 k
    Might try doing it myself if I get a quiet patch.
  • 2002 was known for these Transmission issues , after 2005 5sp Auto improved AW55-50
    Is yours a V70 ie Awd or fwd ?
  • FWD
  • While car has been trouble free it did some weird change downs going downhill in its first 10k . They replaced the valve body under warranty and it did make some difference, with just an occasional flare. For 15k to 150K it never caused any issue at all. In fact lots of things were replaced under warranty without even requesting it. At the time I was clueless about cars and just left it up to the volvo dealership. From 100 k onwards I started to take more interest in my car ; probably because trivets took over the dealership from denlo and service charges became too much to stomach.
  • An update on this issue:

    Car has continued to flare and clunk badly on 2nd gear. Have learned to live with it and drive accordingly. But after a period of constant bad shifts the Transmission service light came on again.

    This time I decided to try clearing the adaptive settings and doing the new adaptation process with VIDA.

    When I changed the fluid in May 2019 I used the dipstick at room temp. So this time (9 months & 6000K later) I used VIDA to tell me when tranny fluid was 85 degrees and found the fluid was low. It needed another 400ml. Topped it up and reset the oil counter again. DTC's showed SLT solenoid was cause of flared or abrupt shifts.

    Upon clearing codes and resetting the old adaptation settings back to factory setting the car drove much better; in fact it felt like a different car. But after doing the full adaptation (hardest part was finding quiet and long level roads so you can do the adaptation properly) it was ok but perhaps not quite as good as the factory setting. I've been driving around with it now and its only flared slightly once in the last 1000k's

    Fingers crossed it stays that way otherwise I'll be doing the valve body nest.

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