Page 1 of 4 1234 LastLast
Results 1 to 15 of 47

Thread: 6 sp crashes going into 2nd gear

  1. #1
    1,000 rpm - releasing the clutch
    Drives
    2000 Special Edition
    Join Date
    Sep 2017
    Posts
    98
    Thanks Given
    21
    Thanked 4 Times in 3 Posts

    6 sp crashes going into 2nd gear

    So I may have figured out why the PO put this up for sale: the trans crunches going from 1st to 2nd (137,000 miles). Now I have in the past had sports cars with this issue and learned to shift them just so, such that I beat the crunch.

    The trans on my Miata tends to crunch less or not at all after warming up.

    Possibly I should try some magical mystery oil?

    Under the car for the first time today (at the mechanic's lift) and confirmed PO's claim of no rust, yes! and the boots on the CVs are good. Yes to that too. And that the exhaust is new and stainless steel, very good.

  2. #2
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts
    Mine does it as well when cold between 1-2. Warm, it's fine. Maybe inspect the clutch hydraulics, bleed them, replace the fluid in the transmission.

  3. The Following User Says Thank You to kung fu jesus For This Useful Post:

    kevinharrop (10-24-2017)

  4. #3
    Super Moderator RotorNutFD3S's Avatar
    Drives
    '99 Brilliant Black Turbo
    Location
    Newnan, GA
    Join Date
    Dec 2011
    Posts
    1,885
    Thanks Given
    2,464
    Thanked 1,473 Times in 698 Posts
    This is unfortunately pretty normal behavior on most Miata 6-speeds. A common recommendation (for 6-speeds) is flushing the current trans. fluid and replacing it with Ford Motorcraft trans. fluid (XT-M5-QS), quite a lot of people found that the 6-speeds behave much better with that fluid, especially at cold temps.
    I've got a lot less horsepower - luckily they are Japanese horses - usually in better shape and more motivated.

  5. The Following 2 Users Say Thank You to RotorNutFD3S For This Useful Post:

    kevinharrop (10-24-2017),Phatmiata (10-24-2017)

  6. #4
    4,000 rpm - entering the fun zone RustRat's Avatar
    Drives
    Red NA8C 1.6L
    Location
    Mediterranean Sea
    Join Date
    Sep 2014
    Posts
    1,234
    Thanks Given
    1,588
    Thanked 944 Times in 465 Posts
    I had the same thing happen to both my 5sp, always making a metal clunk in 1-2 change. Thought it was normal for Miatas in general.


    Sent from my iPhone using Tapatalk

  7. The Following 2 Users Say Thank You to RustRat For This Useful Post:

    Agent☣Orange (10-25-2017),HarryB (10-25-2017)

  8. #5
    1,000 rpm - releasing the clutch
    Drives
    2000 Special Edition
    Join Date
    Sep 2017
    Posts
    98
    Thanks Given
    21
    Thanked 4 Times in 3 Posts
    Quote Originally Posted by RotorNutFD3S View Post
    A common recommendation (for 6-speeds) is flushing the current trans. fluid and replacing it with Ford Motorcraft trans. fluid (XT-M5-QS),
    That stuff is $23 per qt. Does the 6 sp take two or (braces himself) three? Or better yet, 2.1.
    Last edited by RotorNutFD3S; 10-25-2017 at 08:00 AM. Reason: Fixed Quote

  9. #6
    1,000 rpm - releasing the clutch
    Drives
    2000 Special Edition
    Join Date
    Sep 2017
    Posts
    98
    Thanks Given
    21
    Thanked 4 Times in 3 Posts
    Quote Originally Posted by RustRat View Post
    I had the same thing happen to both my 5sp, always making a metal clunk in 1-2 change. Thought it was normal for Miatas in general.


    Sent from my iPhone using Tapatalk
    Normal in the sense that 2nd gear synchros wear out first on a transmission, I can't tell you why. I suppose it gets the most use.

    You have choices: rebuild ($$$) or try RotorNut's magical fluids ($) or learn to shift thru the sweet spot, although there may be no sweet spot. Or live with it. I personally cannot stand the damned crunching, I think I am spending money on magic fluids.

  10. #7
    Super Moderator RotorNutFD3S's Avatar
    Drives
    '99 Brilliant Black Turbo
    Location
    Newnan, GA
    Join Date
    Dec 2011
    Posts
    1,885
    Thanks Given
    2,464
    Thanked 1,473 Times in 698 Posts
    Quote Originally Posted by kevinharrop View Post
    That stuff is $23 per qt. Does the 6 sp take two or (braces himself) three? Or better yet, 2.1.
    Yeah, it's not exactly the least expensive option for fluids, but a lot of people swear by it. I've noticed an improvement on the 6-speed equipped cars I've worked on, with only one car showing no real change. NB 6-speeds take 2 qts.
    I've got a lot less horsepower - luckily they are Japanese horses - usually in better shape and more motivated.

  11. #8
    Super Moderator tsingson's Avatar
    Drives
    99 Silver NB
    Join Date
    May 2005
    Posts
    18,501
    Thanks Given
    12,135
    Thanked 2,066 Times in 1,332 Posts
    I swear the price of that stuff changes by the dealer. I don't remember paying that much. Might want to call around.

  12. #9
    1,000 rpm - releasing the clutch
    Drives
    2000 Special Edition
    Join Date
    Sep 2017
    Posts
    98
    Thanks Given
    21
    Thanked 4 Times in 3 Posts
    Well, I have ordered three qts (my shop could not guarantee getting every drop of 2 qts from the bottle to the trans) at $17 per, ground shipping, should see it in a week or so, and then I'll give you a report.

  13. #10
    Nukuler banned! chiefmg's Avatar
    Location
    N KY
    Join Date
    Jan 2012
    Posts
    1,422
    Thanks Given
    184
    Thanked 1,226 Times in 527 Posts
    The drain and fill plugs for a 6 speed are on the left (driver's) side of the transmission. DO NOT remove any plug from the right side or you will regret it. Easiest way is to remove both plugs, once drained replace the drain plug and then fill from the top until fluid comes out of the fill plug. Oh yeah, and make sure your car is level (seems obvious I know, but I've read stories of people who didn't understand that).
    '00 SE, intercooled BRP MP62, Reverant MS2, Ohlins DFV, Konig Flatout (now X 2)
    __________________________________________________ ____________
    This ain't no build thread!

  14. The Following 2 Users Say Thank You to chiefmg For This Useful Post:

    kevinharrop (10-26-2017),RotorNutFD3S (10-26-2017)

  15. #11
    Super Moderator tsingson's Avatar
    Drives
    99 Silver NB
    Join Date
    May 2005
    Posts
    18,501
    Thanks Given
    12,135
    Thanked 2,066 Times in 1,332 Posts
    You may want to try removing the top one first. That way if you can't, you don't drain it all and not have a way to fill it.

  16. The Following 2 Users Say Thank You to tsingson For This Useful Post:

    HarryB (10-26-2017),RotorNutFD3S (10-26-2017)

  17. #12
    Super Moderator RotorNutFD3S's Avatar
    Drives
    '99 Brilliant Black Turbo
    Location
    Newnan, GA
    Join Date
    Dec 2011
    Posts
    1,885
    Thanks Given
    2,464
    Thanked 1,473 Times in 698 Posts
    Quote Originally Posted by tsingson View Post
    You may want to try removing the top one first. That way if you can't, you don't drain it all and not have a way to fill it.
    Always a good idea! Fortunately if that does happen, you can fill it from the shifter turret (6-speeds only). In which case you use two qts and be done with it.
    I've got a lot less horsepower - luckily they are Japanese horses - usually in better shape and more motivated.

  18. The Following User Says Thank You to RotorNutFD3S For This Useful Post:

    tsingson (10-26-2017)

  19. #13
    1,000 rpm - releasing the clutch
    Drives
    2000 Special Edition
    Join Date
    Sep 2017
    Posts
    98
    Thanks Given
    21
    Thanked 4 Times in 3 Posts
    Quote Originally Posted by RotorNutFD3S View Post
    Always a good idea! Fortunately if that does happen, you can fill it from the shifter turret (6-speeds only). In which case you use two qts and be done with it.
    That's IF you can get your Nardi shift nob off the shift rod.

  20. #14
    1,000 rpm - releasing the clutch
    Drives
    2000 Special Edition
    Join Date
    Sep 2017
    Posts
    98
    Thanks Given
    21
    Thanked 4 Times in 3 Posts
    Well, I have finally got a couple of quarts of Rotornut's XT-M5-QS fully synthetic transmission gear oil into the tranny. I THINK it is an improvement. Shifting seems easier, and the crashing noise of grinding the 2nd gear synchronizer to a fine powder is less pronounced. But I need to evaluate it over a number of days, yes?

    $120 later....

  21. The Following 2 Users Say Thank You to kevinharrop For This Useful Post:

    Agent☣Orange (11-08-2017),NCGreasemonkey (11-08-2017)

  22. #15
    Individual-1 ☚ ☻ ☛ Agent☣Orange's Avatar
    Location
    🍊SWFL🏝
    Join Date
    Apr 2010
    Posts
    21,588
    Thanks Given
    4,763
    Thanked 4,318 Times in 2,543 Posts
    Crashing and crunching are very harsh words. Yes, see how your new fluid reacts and it may take a couple thousand miles.


    No todo que es oro brilla.

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •