Gear changes a bit crunchy.....

[JBT]

Never really thought about it if I'm honest as it's generally seen as better for your gearbox & preventing the syncros from wearing out prematurely.

Rev matching on downshift will save some clutch friction material wear. I's not double de-clutching which essentially means double clutch mechanism wear.

If you really need to double de-clutch an MX-5 transmission to avoid gears crunching, then the tranny or the clutch system is pretty stuffed.

[wasabi]

^^^

Never see double clutching as a necessity in any modern car I've dríven... It's just nicer when down shifting (Just to rev match really).

So my mechanic didn't want to change the gear box fluid yesterday as he said it was pristine. So short of trying that Redline stuff - Which I will probably do in the future - it seems to be confirmed that I've just got the same issues that everyone has

That's all I really wanted to confirm

[gslender]

Rev matching won't allow the engine to bring the input shaft up to speed for better gear changes.

If you have a gearbox that has worn syncros, then double clutching (DC) will improve the gear change performance and life expectancy of the gearbox.

Worrying about clutch wear (an item designed to be replaced) is probably not valid in comparison to replacing the gearbox or repairing worn syncros.

I'd bet that most early MX5s were abused in their young life as clueless owners screamed up to corners in 4th, and then slammed it into 2nd or 1st gear before braking with no consideration to the mechanical pain that the gearbox goes through trying to spin up the input shaft for 2nd gear to match the 80kph speed of the rear wheels. This act wears out syncros and knowing to DC would in fact reduce that. Rev matching doesn't as there is no engagement in neutral and the input shaft is not spun up before the gear is selected - rev matching just saves the clutch.

I'm not sure why people think DC isn't worth doing - probably lost over the years as gearboxes are getting better, but it still improves and extends the life of a gearbox if you do it correctly. The wear on the clutch plate is zero because there is no resistance when in neutral for a few ms, so the only thing getting extra work is the slave cylinder - a $60 part and 15 min job to replace. Big deal. It would probably wear out due to rubber age well before being used to often when DC on the rare times you have to go from 5th/4th to 1st/2nd gear.

G

[wasabi]

Just a quick update...

My mechanic tried out the Nulon gearbox additive in my car. Would have to say there is a very slight improvement when cold (Being pretty generous) but as others have suggested, probably not worth the effort... I'm just confirming it