Rough Downshifting

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  • #1

    Rough Downshifting

    Everything clutch wise in this car I got is fine except sometimes…not all the time…it will be rough downshifting into 3rd and into 2nd, mostly into 3rd is really grindy and rough. Not really bad its just like its catching something. Shifting up is fine and downshifting from 5th to 4th is fine. I also noticed the clutch engages very low, the previous owner also told me that he recently put in a new slave.

    So downshifting for me is so natural! its a habit ive always had and either the previous owner never downshifted and always went neutral and the tranny isnt worn that way, The BW T5 in AEs and Mustangs suck? or some clutch adjustment? or re bleeding? need a lil help guys thanks.
    AE , FMIC, 2.5 Turbo back, BOV, MBC, 8 Pounds, Spectre 12" cone, 350Z rims The old Z31
  • #2
    When was your trans fluid changed last? Have you tried bleeding the clutch hydraulics yet? Does the car still have the stock clutch Dampner? The T5 is the weekest of the Z31 transmissions.
  • #3
    I dont know about the first 3 questions.
    AE , FMIC, 2.5 Turbo back, BOV, MBC, 8 Pounds, Spectre 12" cone, 350Z rims The old Z31
  • #4
    Trbulnt;330341 wrote: Have you tried bleeding the clutch hydraulics yet?
    Curious as to how you don't know this? If you haven't bled it since you have owned the car then the answer is no. As he stated, the T5 is the weakest Z31 transmission so it is very possible that being drove in a certain style for so long and then going to a new owner such as yourself, that your style of shifting is new and causing "unusual" wear to a degree. I would start with changing the fluid in the transmission, bleed the system, and bypass the damper while your at it with a 280zx line.
    Build Log Link: http://z31performance.com/showthread…-VG33-HX35-WIP
  • #5
    ZEricMZ;330364 wrote: Curious as to how you don't know this? If you haven't bled it since you have owned the car then the answer is no. As he stated, the T5 is the weakest Z31 transmission so it is very possible that being drove in a certain style for so long and then going to a new owner such as yourself, that your style of shifting is new and causing "unusual" wear to a degree. I would start with changing the fluid in the transmission, bleed the system, and bypass the damper while your at it with a 280zx line.
    thats y I said maybe the previous owner never downshifted and always went neutral, that's y the tranny isn't worn that way.
    AE , FMIC, 2.5 Turbo back, BOV, MBC, 8 Pounds, Spectre 12" cone, 350Z rims The old Z31
  • #6
    its normal for NWC T-5's, both of mine are funny like that, one is tight into 2nd, the other into 4th (tight, or grinding…) its the constant flaw of the T-5's -- the syncro's. thats really the only real issue with them, the syncro's go out, and then it turns to trash progressively after that.

    I normally will rev match during down shifting, and have much smoother operation.
    Damn dirty angels....these cars!

    Current Daily Driver - 86 Turbo.
    Under the cover - THE BANANA… that needs to be re-energized.
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  • #7
    Looks like I'm gonna have to search for a 30a. My NA2T had the NA 71c and I beat the hell out of it with no problems ever!n
    AE , FMIC, 2.5 Turbo back, BOV, MBC, 8 Pounds, Spectre 12" cone, 350Z rims The old Z31
  • #8
    Is there any slop in the pedal? When the master cylinder starts to fail you will get alot of "dead" space at the beginning of the throw and the engagement point will get closer to the floor.

    I've heard that the T5 kinda sucks, but I've only owned 71c cars.
    5.3 LSx Z31
  • #9
    I blee up 3 71c trannies that were rebuilt plus the factory one. Put in a t5 and it shifted way better than all my 71c's. I dont care if its weaker…lol its the only transmission tyat isnt notchy But thats another story.

    Perhaps the op should check that when hr fully depresses the clutch that the fork at the transmission is fully depressed.
    My Build Thread
  • #10
    Another thing also, if the slave was changed with a parts store $20 slave, then chances are it is leaking and causing low pedal and possibly not fully releasing the clutch. That can make the gears grind or tough to shift. Use only oem Nissan slaves as they are the best, strongest, and last the longest.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily
  • #11
    I'll get under there and look
    AE , FMIC, 2.5 Turbo back, BOV, MBC, 8 Pounds, Spectre 12" cone, 350Z rims The old Z31
  • #12
    Granny shiftin, not double clutchin like you should…



    but for real…
    Does the pedal rest where it should on the safety switch? Try pumping the pedal for a bit and see if you can get it to sit higher and engage properly. Get someone under the car to watch the slave as you push the clutch in to see if it is fully depressed. BLEED IT regardless. Autobone master and slave cylinders are like 25 total, even if they aren't the best, they work and are 6+ times cheaper than an oem nissan one

    Although, for some reason, I feel that this isn't a clutch hydraulics problem. I just rev match most of the time out of habit anyways, my 30a isn't exactly in brand new condition but some gears are tight occasionally, that just what happens when syncros start to wear
  • #13
    Big Slappy Z;340466 wrote: Granny shiftin, not double clutchin like you should…



    but for real…
    Does the pedal rest where it should on the safety switch? Try pumping the pedal for a bit and see if you can get it to sit higher and engage properly. Get someone under the car to watch the slave as you push the clutch in to see if it is fully depressed. BLEED IT regardless. Autobone master and slave cylinders are like 25 total, even if they aren't the best, they work and are 6+ times cheaper than an oem nissan one

    Although, for some reason, I feel that this isn't a clutch hydraulics problem. I just rev match most of the time out of habit anyways, my 30a isn't exactly in brand new condition but some gears are tight occasionally, that just what happens when syncros start to wear
    Thanks slappy! lol ill get on it, its really annoying! imma downshifter by habit haha
    AE , FMIC, 2.5 Turbo back, BOV, MBC, 8 Pounds, Spectre 12" cone, 350Z rims The old Z31
  • #14
    Trbulnt;330352 wrote: The clutch is hydraulic so there is no adjustment per se.
    Well, you can adjust the pedal travel. If it's adjusted in too much, the clutch may not be 100% engaged even with the pedal to the floor. I had this problem when I replaced my master cylinder. There was simply a little too much free travel in the pedal before it engaged the clutch, and once in a while I'd grind a little trying to downshift.
    Zoey - 1987 Z31T GLL - HKS EVC / CM SS 3" turbo-back / Stance GR+
    Black Betty - 2014 Audi C7 S6 APR1
  • #15
    Trbulnt;330352 wrote: The clutch is hydraulic so there is no adjustment per se.
    unfair assumption.

    you can change the slave rod to a longer piece.
    you can adjust the pedal rod with the two jam nuts by removing the snap-pin and adjusting it from inside the car.
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