1989 740 HPT

edited August 2018 in RWD
When it rains it poors!!

First off the gearbox needs help. Hates shifting down to second and overdrive is ok when cold but disengages when it’s warm. Am I looking at a rebuild or replacement? What is everyone’s experience with this?


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Comments

  • edited March 2018
    M46? I couldn't find anyone interested in rebuilding mine so I bought a used one from Mark at Berry.
    goodenough
  • Vee_QueVee_Que (@Vee_Que) South Eastern suburbs Melbourne.
    There was a Rebuilt one for sale on Gumtree in Melbourne, all working. Otherwise I have boxes that are known good.

    The od stopping working is clutches heating up and failing, the solenoid usually just will not work. Though it could be the relay but that's a long shot.
    goodenoughbgpzfm142
  • There was a Rebuilt one for sale on Gumtree in Melbourne, all working. Otherwise I have boxes that are known good.

    The od stopping working is clutches heating up and failing, the solenoid usually just will not work. Though it could be the relay but that's a long shot.

    That makes sense. The old guy said he cooked the clutch because he turned up the boost or something.
    How much for a box?
    My mate has an m47 for a 240. Is that a good option and where can I get an extension to suit a 740?
  • SpacSpac (@Spac) Canberra-ish.
    There are 740 M47s around.
    Should not be difficult to extend the shifter bracket of a 240 one.
    Vee_Quegoodenough
  • 740HPT! Not worth fixing, I think you need to sell it to me 😊
    jamesincgoodenoughEx850RKlaptrap24
  • 740HPT! Not worth fixing, I think you need to sell it to me 😊

    Haha! I couldn’t part with her just yet.
    Just got her up to 140km/h (legally on a road that has a 140km/h speed limit) in 4th gear. The thing hammers. Went to engage o/d but it didn’t engage or maybe I was already going to fast. Didn’t notice much difference. Gearbox is still very usable just hates shifting down to 2nd when going over 40km/h.
  • M90 conversion looking like a good idea?

    I don't know much about the inner workings of the overdrive but from what little I understand high torque / boost shouldn't be applied with the overdrive engaged.
    goodenoughiceton1975
  • vo940 wrote: »
    Gearbox is still very usable just hates shifting down to 2nd when going over 40km/h.

    What happens when you double de-clutch? Does it go into 2nd then?

    goodenough
  • Vee_QueVee_Que (@Vee_Que) South Eastern suburbs Melbourne.
    M90 conversion means throwing parts out he already has, plus if you get a dud box, end up in the same boat as you are with a broken m46. The T5 is a simple swap and can be done cost effectivly, and more importantly, a box can be rebuilt or upgraded.

    Sheer age and incorrect oil would kill the od clutches.
    goodenoughCamT
  • vo940 wrote: »
    Gearbox is still very usable just hates shifting down to 2nd when going over 40km/h.

    What happens when you double de-clutch? Does it go into 2nd then?

    Just tried that and yes a litttle better!
  • M90 conversion looking like a good idea?

    I don't know much about the inner workings of the overdrive but from what little I understand high torque / boost shouldn't be applied with the overdrive engaged.

    Yeah I have thought about m90 in the past but what VQ said if I get a dud box I’m back to square one minus 1500 dollars. I might just use an m47 in this one. I’m not looking for really big power. And yeah I’ve heard that the m46 o/d is not a power gear. I can go more than fast enough in 4th anyway haha
    Vee_Que
  • Ex850RSnoopy (@Ex850R) Somewhere Over the Rainbow. Melbourne.
    M90s available on shipment basis from UK with Berry motor group.
    Straight forward swap no fekin about.
    And being a volvo box no need for engineering approval.
    iceton1975
  • M90s available on shipment basis from UK with Berry motor group.
    Straight forward swap no fekin about.
    And being a volvo box no need for engineering approval.

    I'm sure the T5 is good for many swaps (and easier to rebuild) but being a rare vehicle I'd keep it all Volvo / M90 if it were mine. I believe the M47 was never used on turbo cars?

    Unlikely one of the M90s mported off a parts car was the reason it was taken off the road - however having purchased a couple of these there's no history on mileage so you could get a nice tight one or a very tired unit off a high mileage car, lucky dip. Still worth the chance IMO.
    Ex850Rgoodenoughiceton1975
  • Or I may part out my black one and use the good m46 from that and also the Sachs clutch. My black one has Gemini’s as well with centre caps
  • That also means I can put a complete mint black interior in this one and good instrument cluster
    Ex850R
  • Ex850RSnoopy (@Ex850R) Somewhere Over the Rainbow. Melbourne.
    Swap all over and sell aa other one as a rolling fixer upper, keeps it in circulation.
  • vo940 wrote: »
    vo940 wrote: »
    Gearbox is still very usable just hates shifting down to 2nd when going over 40km/h.

    What happens when you double de-clutch? Does it go into 2nd then?

    Just tried that and yes a litttle better!

    That would suggest that your synchos are worn. Unfortunately M45/M46 synchos are NLA from Volvo, last time I checked anyway.

    All is not lost, since Planetman from Turbobricks (Eric at High Performance Auto in Torrence CA) has a supply of them.
    Vee_Quegoodenough
  • My m46 in my 240t didn’t like boost going past 15 but od worked fine even when the car was doing 180 ( obviously on limitless road in nt ;)
    goodenough
  • Swap all over and sell aa other one as a rolling fixer upper, keeps it in circulation.

    For sure. If I go ahead with it I won’t be scrapping anything
    Ex850RVee_Que
  • vo940 wrote: »
    There was a Rebuilt one for sale on Gumtree in Melbourne, all working. Otherwise I have boxes that are known good.

    The od stopping working is clutches heating up and failing, the solenoid usually just will not work. Though it could be the relay but that's a long shot.

    That makes sense. The old guy said he cooked the clutch because he turned up the boost or something.
    How much for a box?
    My mate has an m47 for a 240. Is that a good option and where can I get an extension to suit a 740?

    Is he sure he cooked the clutch and not the cone clutch in the box? I did a pull in the 245 at 20psi and it ate the cone clutch. Even with a new turbo clutch it still slips in every gear.
    Vee_Que
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