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1987 240 M47 jerks on acceleration

posted by  someone claiming to be Davi d on  Fri Apr 10 23:39 CST 2015 [RELATED]

I Have a 5sp manual 87 240 and I am experiencing jerking on acceleration and cruising. it is the worst in 1st and 2nd gear when I am taking off but this jerking can occur in 3rd gear or even when I am at highway speed although it is much less pronounced. I cannot get this problem to occur without the engine under load but as soon as I engage the clutch and push on the gas it sounds like the engine is not getting enough gas. as I increase acceleration and engage the clutch all the way the car will jerk several times and then even out when I mash on the accelerator. Another thing is that the car will drive fine when I start up but appear after a few minutes of driving.








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    1987 240 M47 jerks on acceleration

    uid 46171's pic
    posted by  kittysgreyvolvo on  Mon Apr 13 06:40 CST 2015
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Sat Oct 18 15:23 CST 2014
    [RELATED]

    A few notions ...

    Your symptoms are more problematic in low gears, so more torque ...

    1. Check the clutch cable adjustment? As the clutch material wears, any clutch cable free-play is used up, reducing the clamping force when you engage the clutch (release the clutch pedal).

    Reference the procedure in your Volvo 240 service manual (Bentley, Haynes).

    Maybe here at https://www.brickboard.com/FAQ/700-900/TransmissionManual.htm

    2. Another cause may be one or more broken motor mounts. The engine-transmission assembly can twist, and that can also exacerbate a tight clutch cable adjustment.

    Though broken Volvo 240 motor mounts is dangerous. Especially is the transmission mount and one of the motor mounts (usually the driver side, I think.)

    3. Rear main bearing (crank seal) leaks so much oil, the friction material of the clutch plate is oil-soaked and probably ruined. Clogged PCV flame trap / oil separator box.

    4. Your clutch is worn out, and other components, require replacement.

    You may need PCV cleaning, motor mount replacement, and clutch replacement outright.

    When was the last time you checked the fluid in your M47 transmission. Best to use Redline MTL. Maybe up a single MTL weight from what the Redline web site recommends if high mileage on your M47 in that 1987 240 of yours. Search the brickboard for the manual transmission overfill method.

    Me mindful of the reverse light switch wires under the transmission tunnel. Insulation wears, causes shorts.

    Questions?

    Search the brickboard. You may find info useful for you. Others may chime in.

    Hope that helps.

    Duff.








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      1987 240 M47 jerks on acceleration ... and ....

      uid 46171's pic
      posted by  kittysgreyvolvo on  Mon Apr 13 14:46 CST 2015
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Sat Oct 18 15:23 CST 2014
      [RELATED]

      The flex coupler, what acts as a U-joint between the transmission output flange and the drive shaft.

      Take a look at the drive shaft center support carrier bearing-bushing assembly. Is it secure? The bushing okay?

      Else, engine operating problems. In lower gears the driver usually depresses the accelerator pedal more than when up-shifting and taking up final drive.

      So, does flooring the accelerator pedal in fourth or fifth gear cause any problems?

      What begins as intermittent failures, such as a failing sensor, corrosion at a wire harness ground point or wire harness connector, or other thingy, can cause "bucking" or "bogging" behaviors as you briefly describe here.

      I did not think of these things earlier. Sorry about that.

      Someone else may come along with useful questions and answers for you, versus what I put forth here.

      cheers.

      forgetful dud.







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