please help me here! ive been told that trucks above the one ton state, use the clutch only for take off, then you just feel your way through the gears ,with out clutching? ive done that with cars and dirt bikes, and was told that it was damaging to do so!
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clutch or no clutch
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It's generaly done on class 7 or 8 trucks with transmissions that are not syncretized.They use sliding gears or siding clutches.sometimes I take it out of gear with the clutch then let off the throttle until it will go in the next higher gear.It's a smooth transition after you get used to it.
cat320
Charter Member
your talking about rpm shifting use the clutch to start and stop. i have done this with an old mack have not driven any of these new transmisions. but i know you can do it in the older trucks
willie59
Administrator
Yep, that's the way you drive big truck trannies. It's really simple why. First of all, the gears are way bigger in diameter and thickness than car or motorcycle trannies, so the mesh is totally different. Second, if you wound out a gear and need to shift to the next high gear, these heavy shafts and gears have inertia almost like a flywheel. If you just pushed in the clutch and try to shift, the inertia has everything turning and you'd still "grind the gear". So you learn to shift by leaving the clutch engaged to keep the engine sync'ed up with the tranny shaft and use the throttle pedal to control engine rpm to match up the gear being engaged. Takes a little practice, but after a while, your shifting as easy and flawless as in a car.
Hendrik
Senior Member
Not a good idea with syncro boxes, as I have heard that not using the clutch can damage the syncro gears.
However yeah, any crash box can be shifted without the clutch, either that or double de-clutch. It does take some practice to get the revs right, particularly on the down shift. On the trucks I drove it was 500 rpm between gears. Once you get the hang of it you can do it in yer sleep.
This is best practiced away from traffic as you can easily get locked out and panic.
Then there is skip shifting which we will leave for advanced class.
Could be, but I had over 150k miles on that pickup when I sold it and never had a tranny problem. :beatsme
Bob Horrell
Charter Member
I only use the clutch for starting out. Even at a stop sign, if I don't have to wait for anyone, I can drop it into a low gear just as the wheels come to a stop without using the clutch. When empty I skip shift a lot without the clutch. A lot of times I only use 4 gears when empty.
Hendrik
Senior Member
This reminds me of a joke I heard a long time ago, not sure if I got it right but here it goes:
One fine day a cop pulls over a bloke in a fancy red convertible sports car, cop says to the fella "you know there was stop sign back there and you failed to come to a complete stop"
yuppie says "ahh come on now officer I slowed down and just about came to a stop"
Cop pulls the driver out of the car and starts pounding him with his stick, after a while he asks the driver "now sir would you like me slow down and almost stop or would you like me to come to a complete stop?"
willie59
Administrator
Hey counter, I'll kick it up another notch above "clutch or no clutch", and give you "no clutch and no throttle pedal". Back in the late '80s, I worked for a crane company. An operator called on the radio and said the hyd clutch pedal on the TMS100 Grove crane dropped to the floorboard, no clutch control. Then his throttle pedal did the same, linkage broke, had no throttle. He pulled over on the side of the highway and requested a wrecker. I radio'd back and said "I'm on my way, I'll get it back home". When I got there he asked "how are you going to drive this thing back?" I said "drive my truck and follow me." On this crane, the only thing between you and the engine is a piece of sheet metal access cover. I removed the cover, and there's the engine right next to me. I put the machine in low gear and hit the starter. It fired up and started moving. Reach into the engine and work the throttle control to wind up the gear with my right hand while left hand is on steering wheel. Take left hand off wheel to shift to next gear while working throttle with right hand to mesh gears, holding steering wheel with left knee! I drove this thing about 15 miles back to our shop like this. Machines ain't nothing like cars or motorcycles.
I've driven all the trucks in my career without a clutch for shifting, both up and down.
A synchromesh tranny can be damaged in this manner if you rely on the synchros to align the gears rather than engine rpm and try to muscle it into gear. If done properly there shouldn't be any additional wear.
A synchromesh tranny can be damaged in this manner if you rely on the synchros to align the gears rather than engine rpm and try to muscle it into gear. If done properly there shouldn't be any additional wear.
Hendrik
Senior Member
Yeah that makes sense, as synchro gears are not as tough as the actual gears.
WesternStar
Well-Known Member
I learned how to float the gears way before I learned how to double clutch. Once you've done it a few times in your particular truck, you just do it by ear and feel. Saves wear and tear on the clutch linkages, and on the ol' left knee too!
crane operator
Senior Member
Had a similar event to atcoequip's, also in a crane. TMS 300, had clutch pedal, but the throttle when it was below 10 degrees would stick wide open. Crane is a single engine for upper and lower and I found I could shift by pulling the throttle control air switch from upper to lower. Button out, full throttle, push button in to throttle down while shifting to idle down, shift, then button back out for full throttle. In a 13 speed. When I explained to the mechanic how I was getting back home in cold weather, he smacked me in the head and told me to quit driving it that way. I told him if he would find time to fix it when I wasn't out making money, he could have at it, otherwise I was waiting for a slower day. So yes, shifting is possible with no clutch, also with no throttle, and other assorted things that most consider as vital to road use.
Buckwheat
Member
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Ive driven manual trannies my whole life and ill tell ya with syncro's its alot easier with the clutch but driven my class eight the clutch is only used when im starting or stoping.
willie59
Administrator
That's a funny story. Sometimes a crane operator is required to operate things other than...just the crane, like upper/lower throttle control switch's so you can shift gears and get back in the throttle.
That's a funny story. Sometimes a crane operator is required to operate things other than...just the crane, like upper/lower throttle control switch's so you can shift gears and get back in the throttle.
Crane work is never boring.It's a multitasking job.
We had a crane operator that must have figured it was boring! We were setting up a batch plant and had to take some time to assemble some stuff and when we finally got done we were signaling to the operator to go ahead and raise it up. kept trying to get his attention only to find out he had fallen asleep!! We were not very amused
We had a crane operator that must have figured it was boring! We were setting up a batch plant and had to take some time to assemble some stuff and when we finally got done we were signaling to the operator to go ahead and raise it up. kept trying to get his attention only to find out he had fallen asleep!! We were not very amused
I had a crane job like that last summer. I was setting trusses on a new home and the carpender had a string stretched acosse the top of the peak.He took about 10 to 15 miniutes to set a truss.I would shut the crane off and wait untill they were ready fore the next truss.Oh well ,I was charging by the hour.
crane operator
Senior Member
Boy - these guys are taking for-ev-er to get this batch plant ready. I already ate most of my lunch. You think they would be ready when they're paying by the hour? Radio is kind of boring. Hmmm - maybe I'll just close my eyes for a little bit ....a little more.........maybe tilt the seat back...... zzzzzzzzzzzzzzzzzzzzzzzzzz. Just fooling with you. I actually can't sleep in the cab, but I used to work with a operator who claimed he could sleep while actually swinging the crane! I never saw it, but I do know if he was sitting still very long, you better plan on waking him up.