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No clutch shifting

2K views 18 replies 13 participants last post by  IanRiordan 
#1 ·
is it bad on a transmission to shift without the clutch? obviously without grinding the gears lol

i tried it couple days ago and its surprisingly really easy to do
 
#4 ·
Umm... that's not exactly true! It's can be very hard on the synchronizers. In other words, the trans won't last as long before it starts grinding gears and popping out of gear. You CAN learn to shift without the clutch though. It's a matter of getting up to a certain speed then shifting. When you're at the right speed (rpm) for your trans there will be little or no resistance pulling out of the gear it's in and sliding into the next gear. If there is you haven't hit the right speed yet. It will take a little trial and error to find it.

At the right speed all the trans internals are turning at near the same speed, so no gear clash. The synchronizers apply force to the shaft the gear is getting ready to slide over slightly before the actual change, getting the receiving shaft a chance to match speed before the gear slide. There is a an engine speed where everything in the trans is at the same speed or very close. At that point you can shift without the clutch. Don't be fooled though! If there is some resistance but it shifts anyway, that's the synchronizers doing their job. If you shift like that a lot you'll wear the synchros out -- they aren't designed to work with pressure on them from the engine.

I "speed shift" my motorcycle all the time when at speed, but I've been riding a long time and can tell when it's time to shift by ear. At low speeds you'll have to use the clutch -- that's why it's called "speed shifting" -- you have to be reved up pretty good to hit the equilibrium range for the trans.
 
#5 ·
so basicly if its done right its fine and if not then expect to be rebuilding the Tranny.

i have done it quite a bit in the last few days and 1 time i got a big clunk like the tranny was coming up through the floor boards and jsut a cuple mild thumps
 
#6 ·
No-Clutch Shifting

Yup, the big rigs do it all the time, but......

The tranny's are designed for it. Remember, they've got thirteen or more speeds with an engine that has a 500 RPM usable range so the revs don't drop much and aligning the gears at the right RPM is much easier.

Do it on a tranny meant to be de-clutched between gears and, like farna said, you'll be doing a re-build. And not only synchros, you're side loading the bearings on the ttansmission shafts too. Not a good idea IMHO.
 
#8 ·
haha

The reason i wanted to learn to shift without the clutch is my Throw out bearing keeps going. my original clutch had 130,000 miles on it and it worked fine but it never engaged untill the pedal was almost all the way out so i thought it was worn and better replace it so i dont have any future problems. well i did the clutch wich included flywheel machined, pilot bearing, disk, pressure plate, and Throw out bearing, i got about 3,000 Miles before the Throw out bearing went, it would grind when i put the clutch in. so i swaped it out and it was good and i got about 600 miles out of this one and it starting to do it again so i bought a whole new clutch kit again and going to try that, im getting really tired of keep pulling the trans on the car, will be the 3rd time this winter in the Cold. The clutch is hydralic and its auto adjustes so there is no pressure on the clutch. and i know for sure its not putting pressure on the throw out bearing.
This problem with the car has been bugging me so much i want to just go run it into a Tree
 
#9 ·
You might check to be sure that your slave cylinder is coming back all the way. Also you could have air in the clutch system. You have to remove the slave cyl and leave the line hooked up and hold the cylinder with the bleeder in the up most position to bleed properly. Its a two man job.
 
#10 ·
It's only auto adjusting to a point. Most slave cylinders have an adjustable end. You have to adjust the clutch initially, and FROM THEN ON it's auto adjusting for wear. The clutch not releasing until the pedal is almost all the way out is correct. Otherwise you have a little pressure on the throw-out bearing which causes it to spin all the time and wear out quickly. It doesn't take much pressure, just enough to make it turn. The throw-out just isn't designed to turn all the time, especially with no pressure on it. I know this doesn't sound right, but with light pressure on it it will wear out faster. It's designed to spin with full pressure on it or not spin at all.

If you don't like the height of the clutch pedal you might be able to adjust the stop. Just make sure the rod on the slave cylinder is adjusted correctly to compensate and the throw-out isn't spinning all the time.

Since you're having so much trouble getting it adjusted you might want to take it to a shop, explain the problem, and see if they will adjust it after you replace. They may not, since you'll be ticked at them if it goes out again, and it could be an installation error on your part. Might be time to bite the bullet and let a shop install a new throw-out bearing. Then if it goes you can blame them for adjustment. Your clutch and pressure plate should still be fine though.
 
#12 ·
farna said:
I "speed shift" my motorcycle all the time when at speed, but I've been riding a long time and can tell when it's time to shift by ear.
But that has nothing to do with this. Motorcycles use a sequential tranny with dog rings. No syncros and a completely different design

You are right though, its tough on synchros. As long as you don't push hard it should be only moderately more wear. Just gently apply pressure and wait for the speeds to match. Kinda a waste though. A clutch is easy to replace compared to new synchros.
 
#13 ·
I didn't realize the MC trans was built that differently, but it does make sense. It's apparently built more like the big rigs -- intended for clutchless or light clutch shifting.
 
#14 ·
The big transmissions have no synchromesh,and have a clutch brake for putting it into gear at a dead stop.

Allthough lots of truckers,myself included,do shift without a clutch,all the major manufacturers of drive trains advise against it,spicer,rockwell,eaton,and others,all say that clutchless shifting puts an undue shockload on the whole drive train and causes premature failure.

Thats what they say,but if your driving for 14 hours a day or so,you cant help but get good at it after a while.

Also,big trucks without synchro must be double clutched if using the clutch,that is you push clutch pedal and pull gear lever into neutral,let clutch back up momentarily so input shaft of trans is engaged to crank and turning the same speed as crank,then push clutch in again and pull into next gear.
Same thing for downshifting,only you rev the engine slightly in the middle of the shift.
 
#18 ·
bolthog said:
if you have a hydraulic clutch make sure you never rest your foot on the pedal because its easier to wear the parts out on a hydro clutch than a mechanical. because it takes less pressure to disengage
i do that often as city driving and constant stop and go in rush hour, its goten to be a habbit that im gona have to stop.

not sure if i should start a new thread or not but the problem i been having is pretty odd. first time after doing the complete clutch after 3,000 miles, whenever i had the clutch in it would somtimes make a grinding sound wich i thought was the throw out bearing. guys at the shop when i had a exhaust joint welded told me it was the throw out bearing as well. so i swaped it out with a new one.

600 miles later i get a screeching/grinding noise again but it is not sounding the exact same and is not acting the same way. i mostly drive city, odd highway somtimes. i have only hear this noise in 1-3 gears. never happends when the clutch is enaged, only happends when the clutch is disengaged with the pedal in. seems like if im coming to a stop and down shifting and keeping the clutch in it will screech and stop when its between gears and come back again when its put into gear again.

This has been happening for the last 2 weeks or so of driving, some days i wont hear it at all and others like yesterday it will be all day making the noise.

This weekend i am installing The new clutch kit
 
#19 · (Edited)
Is it's a car (rwd) or commuter traffic (fwd)? If it's a car or one of the few fwd's to run one check the spigot bush/bearing in the back of the crank. With the clutch disengaged the crank spins around the input shaft, engaged the turn as one - assuming zero clutch slip. Another one to consider, the needle rollers on the mainshaft snout. They don't get loaded as heavily going up the gears as the input and rear cluster bearings but on deccel they cop it, the rear mainshaft bearing can be noisey on deccel - but if it's gone you'll get noise under load in direct (4th).
I shift clutchless and find some synchro boxes (muncie, vw, porsche,aussie m20/21 and 833n/p) are almost as smooth as a road ranger, even my old Range Rover hunting rig (4spd) glides in. All it takes is practice and a GENTLE hand.
 
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