Clutchless shifting

Yes

I am not an auto expert by any means, but I'll tell you what I think. My first vehicle was a 1970 VW van and I knew that transmission well. Aside from taking off from a dead stop, I did not have to use the clutch. I could just slip the transmission from one gear to the next - I could just feel the right time to do it. It got to be something I did just for fun because I could. Make sure you understand, I was not just jamming the shifter into position forcefully, the shifting was smooth as can be. My next vehicle was an Isuzu Trooper, and while it was still possible to shift without the clutch-it was nowhere as easy as with my old VW.

--Dan

In the early days of Formula 1 racing (between the world wars) clutches were so delicate they were used only at the start of the race. All shifting was done without the clutch, and there was NO sychromesh. Yes it can be done, smoothly and without any stress on the gearbox. But it takes lots of practice to devolop the skill, and you'll hear some godawful grinching noises until you get it right.

|> Hi, dumb question: am i likely to cause transmission damage |> shifting without using the clutch ...

If you want to do that, get a dog-ring transmission. Drag racers years ago used to remove 1/2 or 2/3 of the splines on the synchros so they could bang-shift. Not much fun on the street though. Rex in Fort Worth

If you can finesse it such that nothing grinds and it slips into gear easily without forcing it, you won't hurt anything. The question is: are you that good?

|On Thu, 19 Feb 2004 20:46:07 GMT, "dg" wrote: | |>I am not an auto expert by any means, but I'll tell you what I think. My |>first vehicle was a 1970 VW van and I knew that transmission well. Aside |>from taking off from a dead stop, I did not have to use the clutch. I could |>just slip the transmission from one gear to the next - I could just feel the |>right time to do it. It got to be something I did just for fun because I |>could. Make sure you understand, I was not just jamming the shifter into |>position forcefully, the shifting was smooth as can be. My next vehicle was |>an Isuzu Trooper, and while it was still possible to shift without the |>clutch-it was nowhere as easy as with my old VW. | |In the early days of Formula 1 racing (between the world wars) |clutches were so delicate they were used only at the start of the |race. All shifting was done without the clutch, and there was NO |sychromesh. Yes it can be done, smoothly and without any stress on the |gearbox. But it takes lots of practice to devolop the skill, and |you'll hear some godawful grinching noises until you get it right.

Real formula race cars still have no synchros ( they wouldn't last long) but instead have dog rings, a crude engagement hub. You don't use a clutch, you just match the revs and as long as you are close, it snicks right in. I also recall the VW minivan as being easy to shift clutchless. A friend had one, and drove it that way for years. I think that VW transaxle used a type of synchro that was more tolerant of that than most. Plus, the torque characteristics of those engines probably helps. BTW, thousands of those small formula cars use that VW transaxle as the basic unit, although it becomes a Hewland Mk9. Rex in Fort Worth

Clutchless shifting causes a little extra wear on the synchros because they sit there and slip while you apply pressure to the shift lever heading toward the next gear until the engine slows down enough for everything to line up. But they wear in a NORMAL shift by rapidly slowing the spinning clutch disk, too.

But... Its an 87 Mazda.... do you really care? :-)

Exactly how I do it, it is a lot of fun, about as close as I'm going to get to owning a TipTronic! :-)

kristoff plasun

not if it's done right, no grinding with syncros, when learning shift slightly to see if gear can go in.

kristoff plasun

nah, shifting should only be done when gears and engine are in syncro

No, but the next person to own might! :-)

(the thing is still in great condition, especially the engine which had to be rebuilt because I forgot I wasn't driving a VTEC Honda he he)

kristoff plasun

D@mn straight! he he

kp

Not quite. He asked " am i likely to cause transmission damage shifting without using the clutch when engine and gearbox are in syncro?"

I assumed he meant "in synch". Yes he can, if he gets the gears spinning in sych. If he has to practice to learn how, then whether he buggers the gears would depend on how fast a learner he is and how sturdy his gearbox is.

That never happens unless you're shifting a true unsynchronized "crash box", though. On a synchromesh transmission, you can get close but the synchros will hold you off until everything lines up perfectly, whereas a crash box goes right on into gear as soon as the gear teeth themselves line up. If you do it "right" with a synchromesh the synchros barely slide at all, so its probably less wear than they get decelerating the clutch plate on a "normal" shift.