This video is almost 9 years old! Crowns sound exactly the same as this GMC when being shifted, esp.the rear transmission//engined ones.
@SteveCarras
15 жыл бұрын
I take it that the last poster, coilgunner2, was answering your question, kingcamilo. It helps shift the gears of big vehicles and old buses like the one featured [GMC "Highway Traveler" PD-4104, this with 4 gears and non-synchro, located at the back of the bus], and also is done while using the accelator to attain the opposite of what each gear does: i.e., to upshift, you would slow down before doing the above, then downshifting requires a bit of pressure on the gas [as said by many here].
@zimtok
14 жыл бұрын
In an unsynchronized transmission you will be able to shift sooner. The double clutching allows the gears to match speed for easier shifting.
@zimtok
16 жыл бұрын
Old transmissions do not have "syncronized" gears. By pushing in the clutch the first time you are able to take it out of that gear. You have released the accelerator pedal and the engine will drop its RPM. When you release the clutch the transmission will slow down to the engine speed. When you push the clutch in the second time you can put it into the next gear.
@zimtok
15 жыл бұрын
Double clutching is what helps the gears of the transmission match RPM's with each other.
@CreRay
13 жыл бұрын
@XKP69X Push in the clutch, wait a few seconds for the gears to stop rotating, then take 1st gear. If you don't wait long enough you'll get the sound you hear at 0:06
@SteveCarras
16 жыл бұрын
One other thing:On a PDF file form a May 1974 things get Scenicruiser's then 20th anniversary, it mentioned a few electric clutches.Works same, these few "electric clutch" Scenicruisers's [PD 4105] clutches were same as the pedal ones.A treadle was installed instead of the usual pedal (a exception tohugh..).
@zimtok
15 жыл бұрын
Yes, they use it in racing... but mostly for quicker downshifting. For your daily driver the syncros will allow you to shift at a normal speed, and most daily drivers don't down shift ALL the time. If I didn't double clutch with this bus and just waited until the transmission was ready to be shifted I would loose about half my speed gain between each shift. .
@zimtok
17 жыл бұрын
This is a 4 Speed transmission and does not have synchronized gears. It is a 6-71 Detroit Diesel. The throttle response is sluggish at best. Double clutching is not the only way, it is just the BEST way to shift the gears of this bus.
@Donkey2454
16 жыл бұрын
Double clutching is used to match the transmission shaft rpm to the engine rpm to allow smooth shifting on vehicles with no synchronizers or worn ones. It is not used for racing.
@SteveCarras
16 жыл бұрын
PadmeJonez: "You did good, dude! :)" You sure did!
@SteveCarras
15 жыл бұрын
I've read on some site that the 4905's had SYNCROMESH [but were still very hard going like others were---these late sixtiies to seventies models had that reputation, and that's something that I read. Never drove any myself, though.]
@zimtok
17 жыл бұрын
My foot may be touching the clutch pedal but there is NO preasure on it. it takes quite a bit of force to depress the clutch at first and then the air assist helps. It is a smoother transition getting it out of gear when using the clutch. The 671 in conjunction with the accelerator pedal cable length makes it difficult to easily find an engine RPM. This bus does not shift like any truck I've driven.
@andy802diy
16 жыл бұрын
I haven't gotten around to tracking down the article yet, but I do recall that the bus they road tested had a helper axle in the back, but the helper axle was hidden by fairing so that at a glance it looked like there was only one rear axle. If that narrows it down any.
@zimtok
16 жыл бұрын
The shifter is connected to the transmission with mechanical linkage running down the center of the buss just under the floor.
@zimtok
16 жыл бұрын
You are only partially correct... It is the material that is produced here in the US prior to being shipped overseas to then become T-Shirts.
@RustySax
16 жыл бұрын
With only four speeds in this transmission and the Detroit two-stroke motor, best performance comes from winding it up to the governor (2100 rpm) and then shifting. Timed right, it will drop into the next gear at about 1300 rpm.
@zimtok
16 жыл бұрын
Yes a 4 speed as you say just like a car The reverse is solenoid activated... with it in 1st hold the reverse switch and pull it into 2nd position and release the switch. It will not come out of reverse until it is put back into 1st.
@201200098
15 жыл бұрын
modern cars all have synchronizes, which adjust everything so that it shifts smoothly. synchro are not perfect though, so double clutching still gives you a smoother ride if you do it right. also on large trucks and older vehicles, there are unsynchronized transmission, and double clutching is a necessity.
@SteveCarras
16 жыл бұрын
Buses with no clutch brake are GMC MCI With them: Gillig Crown. As one of the previous posters said, pusher don't would not have them, and frankly, I don't see the advantage of having a clutch brake versus using the clutch itself. I'm surprised there are any syncrho's on any large vehicles, even current ones, OR a "clutchless" arrangement with split/range change [like on "Roadranger" set-ups].
@gunterbr
15 жыл бұрын
Old semi-trucks from Brazil also, from the 60s to the 80s. That's what that Portuguese phrase means.
@SteveCarras
15 жыл бұрын
Also, as mentioned here, the higher speed that the gear's supposed to have, the SLOWER it'll turn, nad the intended lower gears relevant to the faster, turn FASTER than the others [mentioned before on this entry form.] Read the previous comments posted.:)
@zimtok
16 жыл бұрын
This 4104 has the air assist installed on the clutch. I recently rebuilt the throttle cable and now it is smooth as silk. Shifting is even easier now then when I did this video.
@zimtok
15 жыл бұрын
You are correct, I have a tendancy of resting my foot on the clutch pedal, bad habit I need to work on....
@zimtok
15 жыл бұрын
If you read through the comments you will get your answer. BUT, In short you release the clutch so the gears in the transmission speed up or slow down to match for proper engagement. Newer transmissions have synchronizer gears to do it for you.
@zimtok
15 жыл бұрын
Yes the motor needs time to slow down. But if you just push the clutch in once you will be waiting a long time for the gears in the transmission to slow down. By releasing the clutch while in neutral (between gears) the transmission input gears slow down with the motor making it easier to shift into the next gear when the clutch is pushed in again. As you have said you don't have to use the clutch at all. This video is to show the rhythm of double clutching I use on this old bus.
@RustySax
16 жыл бұрын
No clutch brake on them, either! Very rare in a "pusher" bus, but often found in a mid-ship Crown or Gillig.
@RustySax
16 жыл бұрын
Yes you can float the gears and shift w/o the clutch, it just takes a LOT of practice.
@SteveCarras
12 жыл бұрын
@boroboyben In additon while 1) upshifting you gotta decelerate before shifting to neutral, then 2) downshiting ACCELERATE before you shift, as mentioned before.
@SteveCarras
16 жыл бұрын
Finally.on the Scenicruisers [not pictured above but still GMC, different model], a final interesting thing:p[probaly known though to most coach owners] Transmission originally was a three speed with a two speed fluid coupling (different bus than the one above which is a 4104, but making an interesting comment),with a dual engine, but this was not that successful, so the Scenicruisers [for those who wonder] sswitched to the usual 4 speed.
@SparkRoomProductions
17 жыл бұрын
I got a 55 GMC 4104...Great Video!
@zimtok
16 жыл бұрын
I can and have driven many vehicles without using the clutch. I'm not saying it can't be done but the old buses are differnet. Have you driven a Bus with a non syncronized transmission or a clutch brake? Add to that a slow response on the engine deceleration and the bus will slow down faster tehn you can get it into gear.
@zimtok
16 жыл бұрын
Yes, For reverse you put it in 1st gear hold the switch and pull it back into 2nd gear, now in reverse.
@Donkey2454
16 жыл бұрын
You can use the throttle to "rev-match" when downshifting...
@RustySax
16 жыл бұрын
Nice video, Scott!
@RustySax
16 жыл бұрын
Not usually, but sometimes you have to if you get your timing off. Since this isn't a synchronized gearbox, it shifts differently than the ones in a car or pickup. You have to wait to make your shifts - no Speed Shiftin' here!!
@denjen010
15 жыл бұрын
can u make another one of these type of videos my friend that would be great man.
@andy802diy
16 жыл бұрын
By the way, speaking of bus performance, Road and Track actually test drove a greyhound bus in 1969. I forget which month (try october). I don't think it was a 4104, probably an MC-something, but it had a detroit of course and a 4-speed manual. It was a full road & track style road test; I think they even did their usual slalom and skidpad tests. It'd be worth tracking down and putting in the reading rack in the head. :-)
@SteveCarras
5 жыл бұрын
4-spd. would be a spicerr-no schyncro. Engine Detoit either 671, 871, or variant.
@SteveCarras
6 жыл бұрын
Sitll a great video at 11! No clutch brake, and, I assume,. if zimtok is still aorund no Jake, either?
@SteveCarras
15 жыл бұрын
If you think shifting a floor-mounted four speed shifter [not to mention the more challenging big riggers]-not to the poster of the video,of course, so much but as to the "newbies" here, - is a challenge, you ought to try [I am not a bus driver, incidentally:)] shiftinga SILVERSIDES [GM 1938-1948,in the pre-1945 years Yellow Cach, GM's org.umbrella]--column shifted and such. There's even a video or two about them.
@SteveCarras
14 жыл бұрын
@XKP69X These rear-transmission/engine buses don't have clutch brakes [as if it hasn't been said already].
@mujjuman
16 жыл бұрын
nice vid. cool bus.
@zimtok
16 жыл бұрын
The "Interview" video was done 4 months before the "Double Clutching" video. It's amazing how much better I got in that time.
@SteveCarras
15 жыл бұрын
Perhaps we should be glad two stick transmisisons exist only on big rigs and "jeeps" and not on buses [GM Futurliners tried this, but these were not rode by the public!] The old stick ones, of cours,e only had one not count cases like Crowns with Roadranger 10 speeds and such.
@SteveCarras
15 жыл бұрын
Incidentally, My GM INTERCITY COACHES book [2003, Iconographix Press, authors Brian Grams and ANdrew Gold-and no Gold'n'Grams jokes, please], states the PD 4104 was built 1953-1960, making it (with the Scenicrusier, GMC PD-4501] one of the first "Fishbowl/slant-ended" styled buses [the type that GM and Flxible used so succesfully later on their transit/suburbans, and making the bus in the video among the last PD 4104's ever built.
@KamiKaziChicken
16 жыл бұрын
It generally helps when you change gear burnerdown1
@zimtok
16 жыл бұрын
You certainly cannot be in a hurry when driving a vehicle like this.
@jmagic32971
16 жыл бұрын
id be limping after 1 hour driving thaat thing ill grind before i go back into double clutching again just watching this video my clutch knee started paining.arrggggh.!!!
@andy802diy
16 жыл бұрын
Sometimes I wonder why the accelerator pedal on busses is not just an on/off switch. Not sure I've ever seen one just part-way down! Also kind of funny how you had to edit between shifts to keep the video from being too long! :-P Ah... busses! I'll get there when I get there!
@zimtok
16 жыл бұрын
I would probably be limping also if it were not for the air assist I have on the clutch. It isn't any harder to push then the clutch on my 65 GTO....
@makipsee
15 жыл бұрын
no i havent but i have driven plenty of trucks that dont have syncros... theres nothing special about double clutching... the only thing it does it allow time for the motor 2 slow down so that the gears will match up
@TrackratM3
16 жыл бұрын
yo man I want that shifter for my civic! that would be Phat man,soes with my 20 inch dubs and my 3 plane wing. 88 civic 780 Hp stock motor with megacan muffler
@rossdsea
15 жыл бұрын
thanks for posting, does not look as hard as people make it out to be. the trick is matching rpms?
@zimtok
16 жыл бұрын
Dusty, I will try it on my 4104 now that the throttle is more responsive. I'm curious to see which way will be a quicker shift.
@SteveCarras
8 жыл бұрын
I'll make a rather pithy and cogent compliment: Given the choice....given the choice of,say, a 2016 (manufactuer name) car or this PD 4104 bus, which would be a dream vechicle (for me this bus...don't worry, I'm not buying anyone's beloved property from them..:)) I noticed by the way that zimtok/Just Stuff's channell (the uploader) switched name back to zimtok, which I've preferred as well since it was the original username.!
@steviedb9
17 жыл бұрын
only on the downshift do you need to blip the throttle, think about it, why would you want to increase the revs when going up a gear? when you go down the gears blipping the throttle syncs the engine and transmission speed giving a smoother change
@SteveCarras
16 жыл бұрын
This is, as we know, a 4-speed manual (with solenoid reverse on the shift from 1 to 2). Now, I guess the shift pattern proper for the 4 forward speeds was just like on a car [minus the synchro for the forward..and I guess the reverse was to ahead of 2nd or to the right (I've heard onclificting comments as to where the switch was swithced to) Anyway, I presume as I was syaing it just had a nomral shift pattern (no over or under). Like this:(excluding the reverse "split") 13 24
@zimtok
17 жыл бұрын
No, I don't "blip" the throttle. It's more like pusing in the clutch and pulling it out of gear at the same time. And then pushing the clutch and putting it into the next gear at the same time.
@BassmanII
16 жыл бұрын
True, I'm more familiar with the Spicers on the MCIs
@SteveCarras
14 жыл бұрын
I also if I drove wouldn't use a clutch brake myself, but then again, I haven't any experience. Maybe a two stick rig would need it. [to the last poster that I replied to] but you'd have to click another KZitem video for that, since this is a 4 speed bus. This is gettin' to be the much asked quesiton here..
@5150ou812
16 жыл бұрын
If you insist on double clutching, only push it about an inch or two. only push it to the floor to get your starting gear otherwise you'll ware the clutch brake out and have to grind it into gear to get moving. You really ought to float it anyway.
@SteveCarras
16 жыл бұрын
MThies's video of a 1966 Dodge has a comment, or at elast one of nthe vids did about this bus having a Synchro (a Gas or stick back then I could understand, having ridden Chevy, Crown, and Ford and such), and can only say a schynro on a bus, for am manual, especially back then, is unthinkable to me. BTW Cars did not have 'erm either until years ago, and of course neither do big trucks, but virtually all of us know that..
@SteveCarras
10 жыл бұрын
Hey, I noted a change in the author's username (originally "zimtok").
@saabdude67
17 жыл бұрын
If you blip the throttle while upshifting you defeat the purpose of a DC upshift... Letting the clutch out in Neutral when upshifting synchronizes the clutch-tranny shaft with the layshaft; therefore, if you blip the throttle, the clutch-tranny shaft will spin faster than the layshaft and you'll crunch the gears even worse.
@SteveCarras
15 жыл бұрын
Are you by chance referring to a) the long time or to b) the fact that many guys would rather drive shift?
@BassmanII
17 жыл бұрын
Not really, on the bus transmissions, especially non-progressive seven speed on down, you have to use the clutch brake to shift.
@zimtok
16 жыл бұрын
Once i get better at downshifting I will do a video.
@BassmanII
16 жыл бұрын
1969? Chances are it was an MC-7. the MC-8 didn't come out until 1973.
@SteveCarras
5 жыл бұрын
Probaly was (MC7s were available as early as 1968-73 in new units, and 1973 as u said was when MC8s became available.
@StanWilhite
13 жыл бұрын
@zimtok Does anyone really teach "double clutching??? You should only use the clutch to start off. Less gear grinding without the clutch after practice.
@RustySax
16 жыл бұрын
You use it until you learn, with lots of practice, how to do it smoothly, then you can practice shifting w/o the clutch.
@zimtok
17 жыл бұрын
Downshifting will come later when I'm better at it. In the mean time just run the video bacwards...(ha ha ha)
@cvueguy
14 жыл бұрын
whats with the dress on the shifter? You can always tell a novice-his left foot is resting on top of the clutch getting ready for the next gear !
@andy802diy
16 жыл бұрын
Nice! But I want to see some DOWNshifting. That's where it counts! :-)
@zimtok
15 жыл бұрын
Have you driven a 1960 4104 bus with a spicer 4 speed transmission? These transmissions do NOT have Syncronizers.. .
@SteveCarras
15 жыл бұрын
I'm not sure if that applies to semi-truck transmissions, though..:-)
@GenericGene
17 жыл бұрын
I classed a few gears when I was learning -
@jigo53
14 жыл бұрын
my 1st gear screeches when i pop it down from 2nd gear (slowing down) do u have any idea what it is? cause i thought double clutch might prevent it
@LoginErroronu
15 жыл бұрын
he must be moving at like 220mph.. look at the camera shake, dahum.
@highway955
14 жыл бұрын
@mtlove91 - youre right but there should be enough freeplay in there tha your not actually disengaging the clutch
@StudManbdk
14 жыл бұрын
whats good about double shifting...why does it help or why would you want to do it?
@ramawson
16 жыл бұрын
do american busses/trucks have syncro boxes? because if they do normaly you wont have to double clutch
@zimtok
16 жыл бұрын
The older buses did not have syncro trans... .
@SteveCarras
16 жыл бұрын
I think that had a switch for reverswe like many pthers.
@jorikrademakers
15 жыл бұрын
that is a race technique for downshifting
@oldsklteg
17 жыл бұрын
i love my sequencial 6 :)
@zimtok
15 жыл бұрын
There is no clutch brake on this bus.... I've tried to lessen the amount I push the clutch but it does not work as well.
@Last-Varangian
17 жыл бұрын
Check out my video on shifting. It is called "Workin Them Gears" I'm in a semi-truck going up and down without touching the clutch until I have to come to a complete stop.
@zimtok
16 жыл бұрын
Is your "rig" a 1960 4104 Bus? Have you ever driven an old Bus?
@makipsee
15 жыл бұрын
no matter what i i have driven i never use the clutch... only 2 take off and never grinded a gear
@SteveCarras
15 жыл бұрын
Someone requested downshifitng, and the poster ["zimtok"] assured once he'd get the hang of THAT, he'd ;post one..but this video itself will suffice..haven't been on one of these for ages..
@RustySax
16 жыл бұрын
There is NO clutch brake on the transmission of this particular coach.
@SteveCarras
16 жыл бұрын
No stick buses with skme exceptions and almost NO bigger stick shift newer or older (certainly NO older) trucks had syncromesh, with some exceptions (I'd rather, again, double clutch those had I driven the trucks or stuff..synchrozied transmission on larger vehicles, either old OR new, doesn't make much sense at all to me.)
@darkmp40
16 жыл бұрын
what exactly is the point of double clutching? i never understood it, when i've driven 9 speeds and 13 speeds i've only clutched just once.. not twice
@andy802diy
16 жыл бұрын
well, if it does have a clutch brake, it definitely isn't working!
@zimtok
16 жыл бұрын
Not true... The lower gear you were in is running fast. The next gear you need to go to is running slower. You need to allow the engine to come down to the slower running gear to engage it.
@zimtok
16 жыл бұрын
Any vehicle/engine can be stalled. I stalled this bus on a hill of all places. Too much clutch release and not enought RPMs will do it every time.
@zimtok
16 жыл бұрын
It is... DD 6-71..
@pwarren1010
16 жыл бұрын
Are you sure?I thought any non syncro has a clutch brake.
@Vicsonvee
11 жыл бұрын
Start the damn thing in gear, like I do.
@ntxic8td
16 жыл бұрын
How come you dont use the throttle to match speeds?
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