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Discussion Starter #1
Hi, I've developed a really annoying issue with my gearbox today. The car still drives as it should when moving around, goes into all gears, however from cold the car changes from 1st to 2nd at around 4000 rpm, then sounds like it's riding the clutch. manual gear changes are very slow and down changes take ages. any ideas? The annoying bit is I upload gearbox software and reflash from cobb, set gear learn, it drives perfect for about 10 minutes then goes back in this mode.... annoying! can anyone help? Car is a 2008 JDM model 650. I'm currently running the up to date gearbox software too. thanks
 

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Is it 'just' when cold, or when at running temp also? The later software does seem to run higher rpm shifts when cold until it starts to warm up (+40deg ish) as the engine wants to run higher rpms as well to warm up faster.
When was your last transmission service? And at what trans temp are you doing your clutch learn at?
 

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Discussion Starter #3
Hi, it's worse when cold but today seems to be a little better. When it warms up it seems to be fine when normal driving, as soon as you switch to ''M'' it is really delayed in changing gear, then if you accelerate hard and change gear like you should it sounds like the clutch is riding pretty bad. Last service on it was 2 months ago. performing clutch learn at +75 degrees.
 

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75 deg is fairly warm for 'general' use learn, will be better for hard driving. Try a learn down at around 60 deg for a more multi-purpose setting and see how it is. With Consult or EcuTek cable you can see which temperature ranges you tend to use most and use as a guide also. As I said, the later software does seem to have settings to allow to heat up the car faster.
Have you done any track days or hard driving that may have over heated the fluid since the service?
 

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Discussion Starter #5
I've tried doing the learn at 50 too but made no difference, the odd thing is that one out of say three re flashes (at weekend) for the TCM made it work fine, but every time the temps go back up it goes back to how it is now. Its like its in a slow mode, but also making the clutch slip (all gear pulls are fine when in them, its just when going from one gear to another). It started to happen after a hard 15 minute drive, however I'm always nervous about temps so I made sure it didn't go over 100 (as had 3 GTR's).
 

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I'm assuming you have not got any trouble codes present or that keep appearing?
As the hardware cannot change, I would try de installing the Cobb, make sure its up to date, then try installing an early software version that matches your transmission/ecu. See how that runs.
 

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Discussion Starter #8
ok thanks very much, I will try that. It weirdly came back to life last night and is working fine. Very odd! I didn't even touch it as was just driving normally and the gears came back quick and blip, then the changes went smooth with no clutch slip. Will see how long it lasts and then if all else fails remove everything and re install stock. thanks for your help though!
 
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