Shifting Without Using The Clutch

[JohnD]

Anyone that's ever been a commercial truck driver knows that big trucks are the easiest things going to shift without a clutch. Old school Detroit Diesels were the trickiest because they gain and lose revs relatively quickly, but still they were way easier to shift than a car. Then they invented air shifters that split the top 4 gears which made going up and down as simple as preselecting up or down then lifting off the fuel slightly and then getting back on the fuel, gently. Gentle touch was always the way in a big truck, getting physical with no finesse just broke shit. Nobody I knew ever double clutched, it was just not necessary. Coarse large toothed gears just drop in and out slick as duck doo when you did it with PERFECT REV MATCHING!!

Perfect rev matching is even more necessary in a car, but trickier to drive clutchless due to relatively fine cut gears and engines that gain and lose revs fast. Best car I ever drove for clutchless shifting was a Lotus Cortina, mid 60s vintage, no idea whose gearbox it was but it was just the slickest shifting trans I ever drove.

The Mustangs' not tremendously precise shifter makes clutchless shifting a chore, it's hard to repeatedly get the shifter in the right spot at the right time to make it just fall into gear like it should.

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[ForTheHordeKT]

Haha, I didn't even know this was a thing. I think I'll just keep clutching it though.

Maybe I'll experiment on the diesel trucks at work LOL. I don't have my CDL, but I'm going to be going for it. I fill up our trucks with ethanol to go down to the Chevron refinery, we load up avgas, diesel, race gas, etc. A lot of times I'll pre-load a truck for a driver who isn't there yet and anymore they let me just pull these things around the yard to my loading terminal.

 

[Gurjit]

had to drive my 88 drop top 5L back home when the clutch cable snapped
reversing up my grandma's driveway then proceeding through 15 miles of moderate traffic on the highway, all the way back home. then another 15 miles to the shop to get it fixed the next day

I row through 13, 15, and 18 speed trucks @ work all the time, very easy to float shift

 

[TexasRebel]

floating gears isn't the best thing to do to a fully synchromeshed transmission. Unless you're rev matching perfectly you are essentially just using the synchronizer cones as your main clutch so instead of working against the transmission rotating assembly they now work against the engine, too.

The thing is, if you start out floating gears with synchronizers you might be developing bad habits that get masked, and you'd never know until you try in a transmission without synchros ... or even without constant mesh gears.

I've always wanted to add a tachometer needle for each gearset in a manual transmission. With the digital dash on the '18s it could be done with a little programming. The axle RPM is known as well as the relationship between the axle and each gearset... no extra sensors necessary.

 

[qtrracer]

I've been doing clutchless shifts for so long I forget not to do it when driving another's car - freaks them out. Also, I've found that some FWD trannys don't like it much. I stopped it on both our Prelude and MINI.

I've been working on a track shift technique; don't like heal-toe or left-foot breaking. Been practicing on the street. Got the downshift pretty good. On the track a week ago, downshift was pretty good/smooth/fast. Upshift was too slow. This tranny lends itself well to clutchless shifting since the gear ratios are nicely spaced.

 

[Boggus]

So what's the magic rpm to shift without the clutch

 

[TexasRebel]

So what's the magic rpm to shift without the clutch

Whatever RPM the desired gearset is running.

 

[Gigantor]

There should be a registry of all cars owned by clutclhess shifters. . .hahahahaha

 

[rambunctious]

floating gears isn't the best thing to do to a fully synchromeshed transmission. Unless you're rev matching perfectly you are essentially just using the synchronizer cones as your main clutch so instead of working against the transmission rotating assembly they now work against the engine, too.

The thing is, if you start out floating gears with synchronizers you might be developing bad habits that get masked, and you'd never know until you try in a transmission without synchros ... or even without constant mesh gears.

I've always wanted to add a tachometer needle for each gearset in a manual transmission. With the digital dash on the '18s it could be done with a little programming. The axle RPM is known as well as the relationship between the axle and each gearset... no extra sensors necessary.

What TR said
you will wear out the syncros
and as a result, the tranny will eventually begin to pop out of gear...
or the syncs wont work gong into gears.
a cool or fun thing to do, but not good on the trans at all over time.
Ramb

 

[lwnslw]

Whatever RPM the desired gearset is running.

I find that my GT/PP will float right into gear at about 1500-2000

As a few have said, it is not the best thing for your tranny BUT to be honest I personally feel it is a must that I learn the right rpms to perform the clutch less shift on every standard car I own. It is a great thing to know for emergencies..

L8R

 

[airfuel]

Use the clutch, these aren't motorcycles.

 

[Norm Peterson]

It's still a useful skill to have in your driving tool kit. I've had to go to it a few times over the years, but it's not something I do on a regular basis.

I'd be willing to bet that on really hasty shifts many people are actually operating somewhere between clutch fully disengaged and fully clutchless shifting.


Norm

 

[CompOface]

Some of us can change gear without using a clutch or stick.

You do realize that automatics have clutches right? Several in fact. You have no choice in an auto, you are using clutches

 

[bumada]

The Mustang will hold the RPMs for next gear when upshifting. Probably makes it a bit easier.

 

[N123456]

Just like an auto.

We get it man..you drive an auto. Fantastic. :frusty:

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