Topic

deeshdeesh
By: deeshdeesh
Posts: 4
Joined: 06/08/11

3rd gear crunch on a 56 reg MX5 with 20k miles?

Posted: Aug 06 2011 Tags:  crunch, downshift, gearbox, grind, nc Views: 87

Hi everyone,

I've had my 6-speed MX-5 (56 reg, 20k miles) for a year now, and have noticed that when driven abit more enthusiastically, the 3rd gear occasionally 'crunches' or 'grinds' when put in. Would also like to say this is after the engine has warmed up too.

This happens even with the clutch fully pressed down, so it isn't that. My car has always been taken care of, and drove quite gently I would say, and just had it's 4th year service in May. But it obviously doesn't do alot of miles as you can see.

Is it possible that the synchromesh on the 3rd gear has worn already?? Or would a gearbox oil change help matters?

Any advice would be much appreciated...

Replies

  1. /My-Page/?userId=6712

    RE: 3rd gear crunch on a 56 reg MX5 with 20k miles?

    Hi , this can be a problem ,especially with the 6 speed box .I have cured it on a few cars by changing the oil to a fully synthetic  GL4 spec oil . Have a word with Opie oils and see what they recommend ,I have always found them very professional with excellent prices .You can ask them via their web site . If you have a few hours spare ! you can read all about what our american cousins do about the problem on the Miata Forum

    2Litre Miyako  Aluminium Silver  Brilliant

    Posted: Aug 08 2011 By: Raptor   Posts: 160
  2. /My-Page/?userId=15077

    3rd gear crunch on a 56 reg MX5 with 20k miles?

    06/08/2011 06:54:56, deeshdeesh said:
    "

    Hi everyone,

    I've had my 6-speed MX-5 (56 reg, 20k miles) for a year now, and have noticed that when driven abit more enthusiastically, the 3rd gear occasionally 'crunches' or 'grinds' when put in. Would also like to say this is after the engine has warmed up too.

     as it only does it occaisionally you are probably just beating the syncro.  ive never thought the change quality was very quick on the mk3 due to the beefed up syncros and internals.  my 5 speed box baulked into reverse so i put in some Ametech MT-10 additive see  americantechnology.co.uk under gearbox additives.   now its better.  also sold on ebay


    youre only supposed to blow the bloody doors off
    Posted: Aug 08 2011 By: mynameismichaelcaine   Posts: 83
  3. /My-Page/?userId=8339

    3rd gear crunch on a 56 reg MX5 with 20k miles?

    08/08/2011 08:14:20, mynameismichaelcaine said:


     ... ive never thought the change quality was very quick on the mk3 due to the beefed up syncros and internals.  my 5 speed box baulked into reverse ...

    Interesting to hear I'm not the only person to experience this with a 5-speed 'box.


     

    Posted: Aug 08 2011 By: Titus   Posts: 5307
  4. /My-Page/?userId=15095

    RE: 3rd gear crunch on a 56 reg MX5 with 20k miles?

    I see... Redline and Royal Purple seem to have been mentioned a few times with varying results. Thanks for the info, nice to know I'm not alone :)

    Posted: Aug 13 2011 By: deeshdeesh   Posts: 4
  5. /My-Page/?userId=2800

    3rd gear crunch on a 56 reg MX5 with 20k miles?

    08/08/2011 08:51:16, Titus said:
    "

    08/08/2011 08:14:20, mynameismichaelcaine said:


     ... ive never thought the change quality was very quick on the mk3 due to the beefed up syncros and internals.  my 5 speed box baulked into reverse ...

    Interesting to hear I'm not the only person to experience this with a 5-speed 'box.


     

    "

     Definitely not! Drunk   I find my 'box incredibly variable.  Sometimes the change is great, sometimes it's not.  It's been the same story since I've had it.  Definitely worse when cold, but sometimes it doesn't seem to want to go into 5th.  Other times it shifts beautifully.  Maybe it's my arm! Zoned out 

    Posted: Aug 13 2011 By: galaxygreybullet   Posts: 103
  6. /My-Page/?userId=2784

    RE: 3rd gear crunch on a 56 reg MX5 with 20k miles?

    Change diff oil at same time.

    Just beware draing g/box oil as if you remove the wrong bolt & hear a clunk it's a box out job as you have just lost the selector!


    2006 2.0 Sport, ILM springs, Cosworth filter, Roddisons race pads, exhaust, geo settings, uprated ARB's & moreCool
    Posted: Aug 14 2011 By: g40steve   Posts: 607