People talk about double clutching every now and again. Usually when dealing with synchro problems. It was also mentioned in "The Fast and the Furious"... Are these proceedures the same or are they talking about two different things? Were they just taking outta their *** in the movie? Is the proceedure on page 21 of the Haynes manual correct? Won't that take time away from you and slow down your race times? How can I work this into my daily driving if it is helpful?

 

Yes, the haynes explains how to do it.
Yes, it will take time to do and slow you down.
Yes, it is good for your tranny.
And yes, you shouldn't pay any attention to anything those people said in the movie.

Cody

 

Historically speaking, double-clutching was necessary in the dark past when gearboxes didn't have syncromesh to assist in downshifts. You had to clutch then pull to neutral, clutch again to select the different gear. Blipping the engine revs before clutching into the next gear allowed for a smooth transition into the next gear as the engine revs met the rpm level of the next gear ratio...


Denny, from the abandoned corncrib...

 

Absolutely right Denny!!! That's what I have to do on my '52 Ford F-3. And let me tell ya...It's a BITCH!!!! It's a 4 speed, and the gears are so low, I usually start in 3rd anyways. But I still can't get it right. I always grind them. Grind'em till ya find'em I guess.

 

Uh-oh...Showin' my age again...
Peace, Love, Dove...Buckaroos

Denny, from the 'ol corncrib...

 

If keeping speed in a race, and saving your tranny are both important..double declutching isn't good...try heal-toe shifting. The RPM's even out and make it really easy on the tranny, while not losing any speed.

 

If you really wanna test your skills try doing both at the same time.

 

Heh... there are two ways to shift into 2nd or 3rd gear in my '7... bang it really fast and ignore any crunchy sounds it makes, or double-clutch it. You can't shift slowly unless you're REALLY patient, because the synchros are worn enough that they almost work.

I thought you were SUPPOSED to double-clutch when you heel-toe... it sure makes it a bunch easier. The fun part is left-foot braking and downshifting WITHOUT the clutch. I used'ta'could do it all the time in my Subaru, I had to because it had the typical Subaru brake pedal mushing 3 inches below the gas pedal so heel-toe was impossible. Heck I could drive that thing all day without using the clutch, or making ugly noises, or taking a long time to shift.

 

They never teach you any of the good stuff in driver's ed. They barely brushed on stick shift, manual transmissions, and clutches in my class. It was all automatic, Put it in D, point the wheel to where you wanna go, big one on teh left makes you stop, long one on the right makes you go.

 

I think a lot of the problems with older Rx-7's grinding transmissions are miss adjusted pedals. Next time you push on your clutch watch how long it takes till you feel pressure on your foot. My 84 used to grind going into 2nd unless I pushed the pedal to the floor and getting the revs close to the gear ratio. I then thought that my synchro was shot but then I adjusted the pedal (the adjustment is under the dash up where the rod pushes on the clutch master cylinder) and BING no more crunch into 2nd. On my car I had ~1.5-2" of travel before It started to actually move the slave cylinder. Something to think about before you think your trans is shot and you waste time "double clutching" every time you shift.

 

There's an easy way to check that.

Start the car in gear, clutch all the way down.

Still holding clutch all the way down, shift into Neutral for 5 seconds, then try to shift back into gear. If it grinds at ALL, then the clutch is staying partially engaged.