Let's say we are looking to upshift. The rpms go up to the point of shifting, the clutch is depressed, and the transmission is taken out of gear. Immediately, the clutch is again depressed (hence, the double clutch), and the transmission is shifted into the next gear. This is done for trannys without sychros (trucks). For upshifting, double-clutching is nothing more than a " timing thing" to allow for the engine rpms to match the road speed of the wheels which allows the appropriate shift.

It sounds complicated, but it is actually a simple concept when you realize what is going on.

David Liske

 

you can double clutch on both synchronized trannies and non-synchronized. it's just the synchronized ones, you can shift without the clutch, which i prefer

 

You're right. But with the example I tried to portray (OK, it may have been poorly written), I alluded to double clutching in large trucks which may not have synchro'd trannys. My specific experience is in driving fire engines, where double clutching is the norm. To double clutch in a modern passenger car is simply a novelty or topic of conversation. It's just not needed.

David Liske

 

thank you.....and so for shifting w/o the clutch

 

hey brentA.....i'm gonna do the h22a swap in my accord starting this saturday and it should be done at the end of next week......just saw that you had a 90 accord lx too, and figured i'd see if there were any parts you need/want as far as the engine/tranny/ecu are concerned....all in perfect condition.....just asking...peace

 

lol....how about a temp knob? heh

 

for 350, you can have the motor, tranny, ecu and the temp knob

 

thats ok im runnin smooth with 107,xxx

 

hmmm interesting discussion here. But im kinda confused. So are you guys saying you can shift without steppin on the clutch?? So just forcing it into gear??

 

You don't FORCE it into gear. You wait till the engine coasts down to the proper rpm, then it just drops into gear.

You can think of the synchros 2 different ways... Normally you push against them till they force the gears to match speed. This works when the clutch is disengaged; synchros aren't strong enough to force the whole engine to match speed.

If you don't disengage the clutch, the synchro blocks you from shifting into a gear until the gears match speed. Just push gently against the gear you want to go in, & wait till the synchro lets you in. When it lets you in, you gotta be ready to push it all the way into gear quickly before it's too late. It's just a little tricky - I'm not gonna let you practice on MY car...

Like someone said, it's just a novelty, or maybe its an education for how synchro's work.