double clutching

[Crofter]

Some driving schools now have very realistic shifting simulators. You can punch in the transmission type and the gvw, and the instructor can throw grades at you, up or down. The lever gives real feedback if you dont match rpms and the grind lets you know. The engine sound is accurate. It shows whether you are clutching too deep and engaging the clutch brake which is only to engage the first gear after idling in neutral. You can wear out a clutch brake in nothing flat if you misuse it. Those simulators are not toys and probably worth 75 grand and save a lot of wear and tear on real gears and lets you concentrate on learning the gears without also having to deal with traffic..

It is not easy to get someone up to speed on a large rig. Some pick it up quick and some I think would never get it. Does not seem to be any way connected with intelligence either. Telling someone how to do it by written instruction is a bit like writing out the instructions on how to play the bagpipes. I could write an explanation on how the gear synchronizers work, but it is not a lot of use in learning how to syncronize them with your ears, hands and feet. A lot of newer rigs are going to entirely computer shifted transmissions as it is not only easier to train a driver but much easier on the entire drive train.

 

[gink595]

Some driving schools now have very realistic shifting simulators. You can punch in the transmission type and the gvw, and the instructor can throw grades at you, up or down. The lever gives real feedback if you dont match rpms and the grind lets you know. The engine sound is accurate. It shows whether you are clutching too deep and engaging the clutch brake which is only to engage the first gear after idling in neutral. You can wear out a clutch brake in nothing flat if you misuse it. Those simulators are not toys and probably worth 75 grand and save a lot of wear and tear on real gears and lets you concentrate on learning the gears without also having to deal with traffic..

It is not easy to get someone up to speed on a large rig. Some pick it up quick and some I think would never get it. Does not seem to be any way connected with intelligence either. Telling someone how to do it by written instruction is a bit like writing out the instructions on how to play the bagpipes. I could write an explanation on how the gear synchronizers work, but it is not a lot of use in learning how to syncronize them with your ears, hands and feet. A lot of newer rigs are going to entirely computer shifted transmissions as it is not only easier to train a driver but much easier on the entire drive train.

Thats intersting about the schools. I learned when I was 18-19 years old working for a excavator/farmer, they were always busy doing something and not afraid of anyone driving their equipment. I learned really quick, they'd call me on the radio and tell me to bring the dump truck down to somewhere and I would tell them I've never ran a truck before and they would call back and tell me to figure it out. I knew the basics of it from the drive alongs but never operated one by myself before.

I will never forget that first trip in a Ford Louisville dump truck with a Detriot, it was a M'fer to shift and forget about down shifting it wasn't happening. But I did go on to learn how to drive one and was OK at shifting and downshifting from hauling grain in the fall. But it has been a few years now since I've ran one. it was kinda fun

 

[smilin possum]

Sell it and get something I could shift LOL. I have never run a even a twin stick 5 and 4 but I would like to give it a shot.

You need to find somebody that has one and get them to let you try it. It's a trip. I don't even know any body around here that has one. I drove for 17 years and then built them for 16 years and they are wild now a days. Auto trans cruise and it's just like driving a car. Cut my teeth in a 1968 International with a 238 Detroit with a 15 speed Roadranger trans. It's in the cow pasture at the guys house that bought it new.

 

[ozzy42]

I Hope some of you guys dont get the wrong idea about floating gears.
That is only for non-synced trannys,usually 9 or more speeds.It will destroy a tranny if you do it with the wrong type.
Something to do with the way the gears are cut [one with straight ,one with them cut at an angle].
Don't ask me wich is wich,I don't know,I just know they are different.

If you try it with a 4spd w/granny like found in most pick -ups ,1,and 1 1/2 ton dumps all you will do is tear them up.






:agree2:With the poster about the super 10 eaton fuller .There are BEAUTIES,Start most times in 2nd gear,work up to 10th ,and only move the shifter 3-4 times depending on wich tranny your using.

The guy who trained me back in 98 hated the way it would auto shift between
10th and 9th and he found a way to trick the tranny/ computer into losing the function,but it would reset the next time you shut down,and restarted the truck,so nothing permanent done to the truck .If I remember right , he would wind out 9th gear on a level road ,and throw it in nuetral,then let it coast for 30-45 seconds,and then it would make the computer have a brain fart and give up .
As for myself,I kind of liked it.

 

[TDunk]

I Hope some of you guys dont get the wrong idea about floating gears.
That is only for non-synced trannys,usually 9 or more speeds.It will destroy a tranny if you do it with the wrong type.
Something to do with the way the gears are cut [one with straight ,one with them cut at an angle].
Don't ask me wich is wich,I don't know,I just know they are different.

If you try it with a 4spd w/granny like found in most pick -ups ,1,and 1 1/2 ton dumps all you will do is tear them up.

Yup. Not using a clutch in a synchro. tranny is very very bad. You can tear the synchronizers out in no time flat.

 

[clutch25]

Yup. Not using a clutch in a synchro. tranny is very very bad. You can tear the synchronizers out in no time flat.

Why...if the gears are moving the same speed...shouldn't hurt a thing....

I learned how to drive semi last fall...during sugar beet harvest. Super 10...

Thing drove me NUTS....I have driven manuals in EVERY vehicle I've ever owned learned in them etc...and for some reason, that thing would still give me fits! The little thumb swithc would throw me....I would rather have a splitter and go through all 5 and start over.

 

[mic687]

I absolutly agree with Ozzy and TDunk. Fuller Roadranger transmitions are the only ones I have driven that you could float. All have been in large semi trucks and have been 9,10,13,15,or 18 speed transmissions. You have to use a gentle touch but it works well when you learn. If you don't know how stick to the old doubble clutch push the clutch in take it out of gear, let the clutch out, push the clutch in put it in the next higher gear. Down shift Push the clutch in take it out of gear let the clutch out,while raising the rpm gently push the clutch in slide it in into the next lower gear. All

 

[ozzy42]

Why...if the gears are moving the same speed...should hurt a thing....
They are made ,and designed differently
I learned how to drive semi last fall...during sugar beet harvest. Super 10...

Thing drove me NUTS....I have driven manuals in EVERY vehicle I've ever owned learned in them etc...and for some reason, that thing would still give me fits! The little thumb swithc would throw me....I would rather have a splitter and go through all 5 and start over.
I've heard that from a lot of guys,some love em,some hate em

.

 

[clutch25]

.

Hate to disagree with you guys about the float shift, but done it for years on all my manual trannies...so have lots of buddies. Never had any problems. Not looking to start a war or show any disrespect just my experience with it.

Done this alot with motor cycle/quad trannies to...the only thing it really reefs on in those is the clutch basket...unless you are REALLY missing the mesh speeds.

 

[asthesun]

Normal shifting would consist of pushing the clutch in, changing gears, then releasing the clutch.

Double Clutching would be pressing in the clutch, releasing it in neutral, then pressing down on the clutch again and then shifting to the next gear.

this is correct. not necessary if you tranny is synchronized properly

 

[mic687]

Hate to disagree with you guys about the float shift, but done it for years on all my manual trannies...so have lots of buddies. Never had any problems. Not looking to start a war or show any disrespect just my experience with it.

Done this alot with motor cycle/quad trannies to...the only thing it really reefs on in those is the clutch basket...unless you are REALLY missing the mesh speeds.

I too have shifted many motorcycles with no clutch they are straight cut gears non syncro transmission. A car or pickup truck if the tranny is worn sometimes although I have never had much success with this. Quite a bit of time behind the wheel of a big truck and they and motorcycles are the only reliable float shift vehicals and you just bang a motorcycle up and down not much finess.

 

[TDunk]

Hate to disagree with you guys about the float shift, but done it for years on all my manual trannies...so have lots of buddies. Never had any problems. Not looking to start a war or show any disrespect just my experience with it.

Done this alot with motor cycle/quad trannies to...the only thing it really reefs on in those is the clutch basket...unless you are REALLY missing the mesh speeds.

Use to never use the clutch when i was a NAPA delivery driver. Had an old S-10 with a 4 cyl. 5 speed. After the the 3rd tranny in 8 months they got wise. The older synchro. trannies could handle the "no clutching" than the newer ones.

When i was racing motocross i use to do the same when the arm pump was getting real bad. Then i got a 4 stroke and didn't have to clutch or shift nearly as much. I think the "cassette style" transmissions hold up alot better. I found it alot quicker to just never let up on the gas, pull the clutch in just a hair, grab the next gear and let go the clutch.

 

[treemandan]

Hmmm, I disagree, the whole concept of double clutching is to get the gear box spinning at approximately the same RPM's as the engine for the next gear, hence the throttle blip when in neutral, so you sentence should read ....

Double Clutching would be pressing in the clutch, releasing it in neutral, blipping the throttle, then pressing down on the clutch again and then shifting to the next gear.

Try it, you'll see what I mean, get that next gear spinning at the right RPM and then get mesh not mash.

Wouldn't make sense to blip since the gear is moving slower than the motor, the motor would have to slow down to be at the same speed. Sounds like you need a tune up
when your foot is off again and your are in nuetral the input shaft is being spun by the flywheel, when it slows to the speed of the gear you want it will go in and it doesn't matter if its syncro or not it will go in.

 

[Lawnmowerboy48]

Dan, are you talking about your subaru or a truck. In my mom's subaru, as in most cars, if you max out the rpms in first gear you can go right to third. Example being pulling out into traffic and flooring it and getting up to traffic speed in first and going right to third.

 

[Kunes]

Non Syncronized tranni's, if you have a fairly new car just single clutch

 

[Kunes]

Dan, are you talking about your subaru or a truck. In my mom's subaru, as in most cars, if you max out the rpms in first gear you can go right to third. Example being pulling out into traffic and flooring it and getting up to traffic speed in first and going right to third.

why would you do that, better off shifting into 2nd subies don't make their power in the high end

 

[Crofter]

TMD; back to the original post, I'd say that was skipping a shift, not double clutching. You are correct about not having to blip engine rpms up while upshifting (unless of course you have let the engine and input shaft rpms to drop below the point of engagement. You do of course have to bring the revs up when downshifting. Shifting without the clutch on a syncro transmission should not harm them if you hold only a light pull against the lever and feel the gears together as you throttle in the right rpm. If you are pulling hard every time when the gears are no where near matching speed and trying to force the small syncro friction surfaces to slow or speed up the entire engine plus the gear, instead of just the gear, then you can wear the syncros out in short order.

Of course if you are trying to force the same out of timing shift on a non syncro transmission there are no syncros to wear and you are grinding big gear teeth together. The actual engaging teeth on the hub and gear body of a syncro transmission are small, straight cut and shallow and the gears themselves are constant mesh helical and only locked or unlocked from their hubs when shifting. The construction really is quite different and much easier to envision if you see the innards.. But like I say even if you take opened up transmissions into the classroom it doesnt seem to help learning the gears any easier for some people. Like I said, like trying to explain in writing, how to play the bagpipes!

 

[turnkey4099]

Yup. Not using a clutch in a synchro. tranny is very very bad. You can tear the synchronizers out in no time flat.

Only if you are so clumsy you can't match rpms. If you are matching rpms the synchro doesnt' even operate.

In a gas rig, it is slower to clutchless up-shift vice single shift due to the time it takes for the engine to wind down. My one experience in a diesel big farm truck double clutching was a disaster as I couldn't break myself of the "wait a bit" habit.

I learned to drive on a 34 chev 1 1/2 ton. Drove a couple bigger trucks with 4sp and 2spd rear end with lever shift, i.e., two hands to 'split shift'.

Harry K

 

[TDunk]

Only if you are so clumsy you can't match rpms. If you are matching rpms the synchro doesnt' even operate.

That's the whole reason they starting putting synchronizers in tranny's was for people that couldn't shift that good. I'm pretty sure even some of the 10 and 13 speeds are being synchronized.

I'm not argueing here, but my old man and i have torn down alot of tranny's. We torn down a 6 speed spicer with 50K that looked like there could have been sand used instead of oil. The driver was about 400 lbs. plus and was to lazy to use the clutch. We've also torn down the same model tranny with 200k and looked like new. Driver was easy on the truck and used the clutch.

 

[treemandan]

Guess this post demostrates that all you idiots can't drive:jester:

I would think shifting a snynrco box with out using the clucth isn't a good idea unless the clutch went out and you had to. If the speeds are the same it will work no problem its just finding that speed that wears the syncros.
My scooby is auto and that runs on a big rubber band anyway.
I also think think that D C-ing is really for big trucks and in most cases not needed. my neighbor kid told me he was D C- ing his Jetta.