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Is my Transmission Broken?

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  • sapote
    replied
    Originally posted by Lee_Enfield View Post
    1. "kick" is mostly on 2nd gear, but can be felt on 1st and 3rd regularly

    2. Nope, just normal driving around town. I avoid reving too high in the neighborhoods to not annoy the neighbors, in this case I shift around 4k and it happens..
    1. Shift into 1st is not an up shift. Say you was shifting 2nd to 3rd, was the shifter kicked back to neutral? If yes then it seems the shifted slider hadn't fully engaged in the synchro teeth and clutch was engaged causing too much load and the barely engaged gears were popped out.

    2. Say you were in 2nd and at 4k rpm, then after disengaging the clutch the tranny input shaft needs times to slow down below 4K in order for the gears to shift into 3rd.

    HAve you checked if the clutch is fully disengaged when pedal is down, and how did you know if total disengged?

    Last edited by sapote; 06-05-2022, 03:15 PM.

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  • Lee_Enfield
    replied
    Originally posted by sapote View Post

    Only happened when driving aggressively? During shifting up, the next higher gear needs a lower engine RPM, and I think you had too high rpm and the synchro blocked the shift.

    Nope, just normal driving around town. I avoid reving too high in the neighborhoods to not annoy the neighbors, in this case I shift around 4k and it happens.

    On the other spectrum when I do shift higher it happens as well.

    It happens probably 80 percent of the Time, sometimes it pops in smooth.
    Last edited by Lee_Enfield; 06-04-2022, 07:03 PM.

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  • sapote
    replied
    Originally posted by Lee_Enfield View Post
    Not a gear grinding noise though. Only seems to happen when shifting up, down shifts seem to just pop right in
    Only happened when driving aggressively? During shifting up, the next higher gear needs a lower engine RPM, and I think you had too high rpm and the synchro blocked the shift.


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  • 01SG
    replied
    The ZF is a gem. No doubt it is easier to use. But as you mentioned, the Getrag has a lot more power to deal with, and that changes its nature. When you think about how the e39 m5 uses the same transmission, maybe it did not have to be that tough. Then again, they also used it on the Euro e36 m3.

    It is still a great box and a joy to use. It is just high-strung and takes some getting used to. Also, it is more satisfying when you get it right.

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  • tlow98
    replied
    All this talk makes me want to keep my ZF 5 speed, but I really wan the sixth ratio as I’m getting more aggressive rear end gearing. Le sigh!

    the ZF is so incredibly smooth and easy. I knew they upgraded to the 420g, but I don’t think we really needed the torque coverage that the 420g provides. Then again, I don’t know all the trade offs the engineers had to make.
    Last edited by tlow98; 06-03-2022, 08:10 PM.

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  • 01SG
    replied
    These are very robust transmissions. They are also very finicky. I have to concentrate more with this car than, for example, an e36. The Getrag does not seem to like anything but a perfect shift. There may well be a real problem, but you might benefit from changing your technique first. I have to shift this car faster than others. I think I get what you are talking about when I go from second to third too slowly, and on first to second without enough revs.

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  • Lee_Enfield
    replied
    Been driving the car more, and have a better overall description of what is doing.

    The weird "kick" I mentioned feels like something is hitting the lift linkage, it can sometimes be heard as a clicking as well. Not a gear grinding noise though. Only seems to happen when shifting up, down shifts seem to just pop right in. It only happens when car is moving, not when stationary. "kick" is mostly on 2nd gear, but can be felt on 1st and 3rd regularly, and occasionally on 4th and 5th. Sometimes I get a smooth shift into 2nd, but can never really replicate it.

    As for the not going into gear thing, I seem to have gotten a feel for when it does not go in so can mitigate.

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  • sapote
    replied
    Clutch in act on this 1973 CSL (predecessor to the M3). I wonder what is the red line on this vintage 2-valve single camshaft engine (I'm not sure the CSL has dual cams or single but my 1973 3.0CSi only single). Those door plexiglass were bent like a bow at high speed -- couldn't they stiffen up for less bend to have better aerodynamic drag?
    Last edited by sapote; 05-10-2022, 07:43 PM.

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  • sapote
    replied
    Originally posted by Jimbo's M View Post
    Didn't realize that was normal. Thought it was my M being my M. That said, it's quite frustrating trying to hit third at 8000 rpm and all you feel is a wall. Once I get below ~6.5/7, it'll go in. I think I'll still keep'er anyway.
    When the clutch pedal was pushed -- clutch disengaged -- the clutch disk was fast like a spinning top and its inertial is very high and took some seconds to slow down by itself, or shorter time by slowed down with the synchro (driver pushing the shifter to engage the synchro), or by double clutch: because the engine slows down faster than the clutch disk, and so by engaged the clutch (in neutral) will let the slowed down engine to pull the faster spinning clutch disk down to match with the 3rd gear, then disengage the clutch and shift into 3rd (this helps shifting in to 3rd quicker than just pressing the synchro to do the job). To do the whole double clutch fast, you don't need to completely let go the clutch pedal all the way up, but just let it up 1" or so (where the clutch start biting point) and this should be enough for the engine to slow down the clutch disk), then declutch and shift into next gear.

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  • Lee_Enfield
    replied
    Well that's good to hear at least. Thanks for the input.

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  • Cubieman
    replied
    Originally posted by Jimbo's M View Post
    Didn't realize that was normal. Thought it was my M being my M. That said, it's quite frustrating trying to hit third at 8000 rpm and all you feel is a wall. Once I get below ~6.5/7, it'll go in. I think I'll still keep'er anyway.
    Exactly, that is a better description, it does feel like you are hitting a wall. I want to be competitive with my buddies E60 M5 but I always have that issue.

    I stopped that a while ago though, not the car to drag race in.

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  • Jimbo's M
    replied
    Originally posted by sapote View Post
    This sounds like the rpm was too high and not synced to the output gear, and so the synchro was blocking the gears from engaging which is normal. If it was
    at 8000 rpm with 2nd, then 3rd only can engage if rpm drops lower.
    Didn't realize that was normal. Thought it was my M being my M. That said, it's quite frustrating trying to hit third at 8000 rpm and all you feel is a wall. Once I get below ~6.5/7, it'll go in. I think I'll still keep'er anyway.

    Leave a comment:


  • sapote
    replied
    Originally posted by Cubieman View Post
    Maybe part of that was me nervous during a drag race but after that "blocked 3rd gear" deal happened 5 different times on my 2/3 shift I'm sure I've got a synchro issue or maybe linkage issue.
    So it was not much of a race with the 3rd gear blocked

    This sounds like the rpm was too high and not synced to the output gear, and so the synchro was blocking the gears from engaging which is normal. If it was
    at 8000 rpm with 2nd, then 3rd only can engage if rpm drops lower.

    Leave a comment:


  • Cubieman
    replied
    I have an issue going into 3rd sometimes and it sounds similar to what you have described as the "kick" possibly.

    I normally don't ever launch the vehicle or slam shift it etc. but the few times I have done that I have had a 3rd gear issue almost each time.

    When I am really on it (semi-redline shifts) and going from 2nd>3rd gear sometimes while entering 3rd it feels as though something is "blocking" my ability to engage 3rd. I will try to slam it into 3rd, and if I feel this "blocking" sensation and continue to push through and attempt my shift the gears almost always grind which is terrible at ~8k.

    Maybe part of that was me nervous during a drag race but after that "blocked 3rd gear" deal happened 5 different times on my 2/3 shift I'm sure I've got a synchro issue or maybe linkage issue.

    During regular street driving or even faster driving all is well, there is only sometimes a slight "snick" during a 2/3 shift, feels like a linkage issue if anything there.


    The car basically blocking me from 3rd when drag racing told me not to ever do that again, made me feel bad to do that to the E46 M3.

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  • bmwfnatic
    replied
    I am going to have to agree with heinzboehmer, my experiences are similar.

    When I first got the car, the next day when I was leaving the neighborhood the same happened to me, somehow wasn't fully into 2nd gear and ground the gears.
    Having driven manual all my life this shocked me, it happened a few more times since then, but only like right after driving away in the morning, leaving the neighborhood at ~15 MPH.

    I think my muscle memory somehow adapted to the 'longer' and 'double-notchy' throw into 2nd gear, because thinking about it now, the issue hasn't come back for at least the past 2 years.
    I have changed nothing with regard to attempt to fix it, so it kinda fixed itself I suppose.

    So I think I am going to call this one normal as well, do note that it never happened to me at significant speed / revs, if it does, then perhaps your gearbox is broken.

    Hope that helps.

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