240 Wont shift into overdrive

Discussion in 'Volvo 240' started by tlr1000, May 10, 2007.

  1. tlr1000

    tlr1000 Guest

    Hey all,
    Yesterday on the way home it took my '90 240 quite a while to shift
    into overdrive on the highway. This morning it never did.

    I tried hitting the overdrive button a few times to no avail. Does
    this indicate I'm going to need a new tranny or is their a possibility
    it could be a fuse or switch???

    My Haynes manual didnt have a clear answer.

    Thanks in advance!
    tlr1000, May 10, 2007
  2. tlr1000

    James Sweet Guest

    Did the arrow light on the dash stick on? Usually this fault is the
    overdrive relay, the solder joints inside develop cracks. The wiring to the
    solenoid on the transmission can be damaged as well. It's almost never a
    problem within the transmission itself.
    James Sweet, May 10, 2007
  3. tlr1000

    tlr1000 Guest

    No the light would go on and off when I pressed the button.
    tlr1000, May 10, 2007
  4. tlr1000

    clay Guest

    Mine stopped working a couple weeks back.
    The light burned out years ago... putting off that fix until I have time
    to do the speedo cable and odo gear at the same time.

    Maybe gonna go after the OD this weekend.
    Question is, do I start at the switch (easy to get to but hard to get
    at) or underneath at the relay (hard to get to but easy to get at)

    Maybe put it off until winter. As long as it's 80 or so outside, the
    relay works...
    clay, May 10, 2007
  5. tlr1000

    Glenn Klein Guest

    You need to check under the car to see if the wire coming out of the
    shifter bucket is broken if it is then splice a new section in & your
    problem is corrected
    Volvo Certified Technician
    ASE Certified Technician
    Glenn Klein, May 11, 2007
    viktor weisshaeupl, May 11, 2007
  7. I had a problem with a 745 TD overdrive some time ago. As much as I remember the
    pilot light and the solenoid are both activated by voltage from the relay. In my
    case the the light behaved in a parallel manner with the mechanical switching or
    nonswitching, sometimes switching/lighting happened many seconds after pressing
    the button. This meant that the relay did not react properly to the button. I
    changed the relay and everything worked well again. In your case if the pilot
    light goes on and the shifting does not happen, the fault should be somewhere
    between relay-solenoid cable-solenoid-gear. I would check the cable connection
    between relay pole and solenoid conncector. I do not remember which number the
    relay pole is but you can find it out from a wiring diagram. The cable between
    the pushbutton and the relay inside the gear shift rod is also a weak point I
    have learnt but that should be ok in your case.

    viktor weisshaeupl, May 11, 2007
  8. tlr1000

    Solomon Guest

    I wouldn't bother checking anytihing electrical without first checking
    the fluid level.
    Yours is a classic sympton of nothing more mysterious than a slight
    fluid leak, that over time finally depleted down to a low level, of
    just not enough fluid left in the tranny to aperate the OD.
    The fact that at first it took extra long to shift is the telltale
    It stopped shifting altogether just when the level depleted further.
    Solomon, May 13, 2007
  9. A wiring short/ground is the most common cause of 240 O/D shift failure.

    The positioning of the wiring running from the gear shift through the
    floorboard down to the transmission has more than one weak spot. The wiring
    itself is draped over the top of the tran housing, down the side to the O/D
    solenoid visible from the under the car. You will have to get under and
    inspect the spots where the wire can bounce up and down against the tran
    housing, wearing off the wire insulation over time and causing a
    short/ground. Also, where the wiring is molded into the solenoid is a spot
    that road grease and debris can cause to break down, causing short/ground.

    An exposed short/ground is easy enough to fix by adding insulation. You may
    need to splice in a good repair wire section. To complete the repair, wrap
    all the wiring inside one of those accordian style wiring tubes.

    If the plastic/rubber molded section of the solenoid where the wiring is
    attached is cracked/splitting, pull a good one from a pick-n-pull junkyard
    for a few bucks, test it on a 12-volt battery circuit (you will hear a tiny
    click switching it on, and again switching it off).

    If none of the above are the cause, don't forget to check for a blown fuse.
    Pat Quadlander, May 13, 2007
  10. tlr1000

    tlr1000 Guest

    Thanks for the suggestions. I didnt have time to check it this weekend
    but I will be looking at it today. I will post if I find the problem,
    otherwise its off to the mechanic. Oh well, first time I've had to
    actually think about taking it to a mechanic in the 3 years I've owned
    it. Not bad for a 20 year old car.
    tlr1000, May 14, 2007
  11. tlr1000

    Tim McNamara Guest

    Been there, done that. It's most likely the OD relay has failed. You
    can repair or replace it by taking out the glove compartment and looking
    in to the left, towards the center console (assuming a left-hand drive
    car; I imagine it's a bit different in a right-hand drive car). It's a
    (IIRC) small white box.

    If you're comfortable with soldering you can inspect the circuit board
    inside for signs of cracking and resolder, or you can replace the relay
    for pretty cheap. Take you about an hour if you choose to resolder, 20
    minutes if you replace and have the spare on hand before you start. If
    you do it again someday, it'll take you 10 minutes. The most time
    consuming part is removing the glove compartment and putting it back in.

    I've had to do this in three out of four 240s in our household over the
    past 6 years. The one that didn't need it had a manual transmission.
    Tim McNamara, May 14, 2007
  12. tlr1000

    Tim McNamara Guest

    YYMV of course, but in 100% of cases (n=3) at my house the cause was an
    OD relay gone bad. It's a 10 minute fix, see my other post.
    Also a distinct possibility and one that might point to a cause other
    than a bad relay.
    Tim McNamara, May 14, 2007
  13. tlr1000

    James Sweet Guest

    I've seen them in white, green, red, and orange depending on the year and
    whether it's a manual or automatic. The manual transmission cars with
    overdrive have a relay too, but it tends to be used less so it usually lasts
    longer. With the automatic cars, the relay is engaged and supplying power to
    the solenoid 99% of the time the car is running.
    James Sweet, May 14, 2007
  14. tlr1000

    James Sweet Guest

    I should add that if the wire over the transmission chafes, it will often
    cook the relay and then sometimes blow the fuse so you may have two or all
    three common causes all linked to one initial fault.
    James Sweet, May 14, 2007
  15. tlr1000

    Tim McNamara Guest

    That's not exactly the best case scenario.
    Tim McNamara, May 15, 2007
  16. tlr1000

    Tim McNamara Guest

    I didn't know the manual transmission cars have an OD relay. That seems
    odd in a 5 speed manual transmission. In the case of that car (an 1987
    245), it got totaled perhaps before those problems surfaced- certainly
    before the wiring harness self-composted. Man, that was a darn good
    car- I miss that one.
    Tim McNamara, May 15, 2007
  17. tlr1000

    tlr1000 Guest

    I pulled the glove box and found the box. With the car on and I hit
    the O/D button, the box makes a clicking noise. Does this indicate its
    bad or working? I crawled under the car this evening and there is one
    spot where it looks like insulation is missing. I think I'm just going
    to bite the bullet and pay someone to do it.

    Thanks to all for taking the time to reply!
    tlr1000, May 15, 2007
  18. tlr1000

    James Sweet Guest

    In 1987 the non-turbo manual cars went to the M47 which is a true 5 speed
    and has no relay. The earlier cars as well as turbos had the M46 which is a
    4 speed manual with pushbutton electric overdrive.
    James Sweet, May 15, 2007
  19. tlr1000

    James Sweet Guest

    That doesn't tell you either way, you have to pop the cover off the box and
    inspect the solder joints on the circuit board, they will probably be
    James Sweet, May 15, 2007
  20. tlr1000

    clay Guest

    I popped the relay out tonight and looked at the joints closely. No
    apparent cracks (to these 47 year old squinties anyway.)
    Sweated the ones that looked questionable.
    Put it back together. Now I hear clicking at the relay and under the car
    when I push the button.
    Whatever I touched, musta' fixed it.
    Just once though, I'd like to see a crack instead of randomly touching
    up the joints...
    clay, May 16, 2007
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.