Well, my dilemna has come to fruition. I dropped my car off last weekend and they replaced the 6 speed.

The second gear that was crunching in the cold, well...it still feels a little notchy but certainly improved over what it was before. Hopefully it will stay in good condition.

The service order says that pieces of metal came out of the tranny when they drained it. So I wasn't crazy. However, I'm wondering why this would have been. I've been driving stick shift since I've been licensed, and have practiced double clutching on downshifts for the last 8. In other words, I baby my transmission. I don't power shift or abuse my car, well at least not the transmission.

In any case, the 06 G35X kind of grew on me. Slower, but it had a bit more torque down low. The stereo blows the 07 SOW out of the water. Other than that, I miss my girl.

CHris

 

Great, that means the new tranny on the 07 isn't any better.

 

Really? I had a 06 G35X loaner when I took my 07 in for service. The 06 also had the Bose system and I think the 07 SOW is definitely better.

 

Can someone confirm this for me: double-clutching is not necessary in modern day automobiles. I used to do that in my Mazda6 (my first manual -- don't laugh). I'd shift to neutral, tap the throttle, then downshift. Then I read online and learned from friends that you can just tap the throttle when your clutch is disengaged (clutch pedal down).

 

yes, for the last FIFTY YEARS cars haven't required double clutching.

 

Double clutching isnt necessary in modern transmissions, thats what the synchros are for. Or in my case, supposed to have been for.

With that being said though, use or abuse any part and it will wear out. I'd rather use the cheaper/easier pieces to replace and hope I will never need to.

Modern clutches still work under the same principle they always have from what I know. If the clutch is fully depressed, the pressure plate should be able to slide freely on the input shaft disengaging the tranny from the engine. So in effect, blipping the throttle wouldn't do anything to the tranny, making a double clutch necessary for the smoothest, least damaging shift.

 

Chris, too bad Infiniti couldn't replace your tranny with the upcoming revised 6MT in the 08s. Anyways, when are you due to get it back?

 

What you're describing isn't double clutching. It's rev matching. Double clutching isn't necessary, but rev matching on downshifts is always good.

 

Wow! Transmission replacement already??! Mine felt a little notchy in the beginning but nothing out of the ordinary 'new car' break in stuff. Buttery smoothe now with about 4k miles on the clock.

Wonder if you got some kind of rare defective one. Please keep us posted on this. Could be a possible problem that many more of us may come across later.

 

and what would be the difference between double clutching and rev matching

 

You let up the clutch when you double clutch.
You don't have to do that when just rev-matching.

double clutching is *needed* for those trannys that don't have a synchro.

 

have you tried using redline MTL tranny fluid?

http://www.redlineoil.com/products_g...p?categoryID=7

 

umm, it is double clutching.

Normal shifting in car with synchros --> clutch-in, move shifter down to next gear or deired lower gear, ease the clutch out.

Double clutching, can be done in a car with or without synchros --> Clutch in, move shifter to neutral, clutch-out, match revs to desired level based on lower gear your going to go into, clutch-in, move to desired lower gear, clutch out. (2 clutch ins, hence the doble clutch)

While doing this in cars with synchros isn't necessary, as has been stated, it can also be used when wanting to downshift while in bad driving conditions (slippery roads). By double clutching it makes the transition smooth, as opposed to being relativly jerky by letting the synchros handle the rev match.

 

Okay, I'm confused. So yes, I did "double clutch" in my Mazda6. That's because I thought that it's bad to depress the clutch (pedal down) and step on the throttle at the same time.

In both cases, I'm rev-matching. The only difference is, in double clutching, I go to neutral and let the clutch out (pedal up). I find, however, that I can do a better job of rev-matching when double clutching, versus regular down-shifting when I blip the throttle without going to neutral first. The downside is, it takes too long.

 

that's exactly correct, and the reason why people do it.

engaging the clutch (releasing the pedal) connects the input shaft of the tranny to the motor, allowing you to use the motor to spin up the half of the tranny that is freewheeling, and then sync it with the other half that is connected to the wheels.