Unusual clutch problem

Driving home after a car show over the weekend my clutch would not fully engage. Had an interesting drive home thru traffic until I remembered about double clutching.The Speedster was hard to shift, did not want to down shift and would not go into gear from a dead stop. Had to either put it in a lower gear before stopping or once stopped, shut off the ignition and place into gear before starting. once in gear the car would still rokk forward with the clutch fully depressed. With a breakdown at hand and Carlisle just around the corner the clutch wasn't the only thing fully depressed. As soon as I made it home I went to Speedster Owners website and read everything concerning clutches by using the search feature and the knowledge section. I then checked the clutch cable & boden tube. They appeared to be OK. Called Kirk at Vintage on Monday and he was very patient and offered advice on other areas to check. He even offered to look at it for me but I explained that the trip to his shop w/o a clutch was a bit much from Virginia. I checked the welds at the boden tube and at the transmission and both were Ok. Hoping the engine would not have to come out , I drove to a local VW mechanic seeing $$ fly out the window the whole trip.
The problen turned out to be a broken clutch pedal, The clutch pedal assembly had a crack bu the pin that secures it to the shaft allowing the pedal to bind and never fully engage the clutch. He peplaced the pedal with one off a parts car he had at the shop and sent me on my way only a few dollars poorer.

explain double clutching... a term ive heard but never used or read about.

actuating clutch between gears, used to match revs between eng/trans.
with non syncro'd gears.

Double clutch.....using both hands.

Ok, double clutching is to depress the clutch once, and then immediately a second time, some times slightly revving the engine in-between clutching. This allows the engine rpm to match the transmission/wheel RPM, and allows the transmission synchros to catch up so that the gears will mesh rather than grind, since they are theoretically turning at similar speeds after the double -clutching manuever.

Often done when the syncros in the manual tranny are bad. Truckers often shift without the clutch, by just using their Ear, and the seat of the pants to listen and feel for just the right instant to shift.


GClarke "The vacaville Guy"

so you can pull from one gear to another without the clutch if you do it at just the right instant? dont think ill be trying this.

i usually dont let off the gas when im really DRIVING so does that help the rpms rise as if i were double clutching... i just dont really see how this changes anything. wouldnt that all increase time to shift?

Double clutching is something I taught new "Big truck" drivers to do dbl clutching between gears is the only way to shift thru a 10 13 or 18 speed trans...I'm now to the point where I use the clutch to drop it in gear from a stand still and then shift smooth as butter thru the rest of the gears both up and down range. Seriously, this can easily be taught on a speedster, pick up truck etc.

Alan

Stacey,

Glad to hear your problem is solved, it was an inexpensive fix and you're back in motion, I'd hate to have you miss Carlisle.

Remeber Steve McQueen double clutching in Bullit?
Ron

i still dont understand... :( why is this better? or is it?

ok i got it now after reading here...

www.driversedge.com/race.htm - well not that article, but its a funny one... theres another about double clutching.

i guess i try to do this while heal toe braking/downshifting, but usually i just hold the clutch until im at my speed where i know where the engine rpm should be, as i am braking or coasting with the clutch in ill just pull from 4th to 3rd straight without ever letting the clutch up.

so i push in the clutch, ball of my foot hits the brake and my toe gets to play with the gas... as i slow into a corner, i will blip the gas a bit over where i know it needs to be, pull from whatever gear i was in, to what ever gear im going to as i let off the brake and hit the gas at the right rpm accelerating... am i not letting the synchros match because i dont leave it in neutral with the clutch out for a split second? it sure is a fast way to do it, but if i can get as fast doing what you all are talking about and be less stressful on my tranny, i'll try to learn the to double clutch.

Oh....I thought double clutching was having a cold brew in each hand... eh?

nic double clutching is a waste of time with a modern syncro'd
trans. to prove the operation of the syncro's, while driving in second
gear take it out into neutral, place slight pressure on your
stick holding it against third (remember no clutch) when the revs
match the stick will magically go smoothly into third. if it
doesn't you can blip the throttle and it will pop into place.
no grinding or other troubles!

Yeah, but you have to be careful about briskly pulling it into the next gear (either up or down) as the revs match or you miss your opportunity and it'll grind a bit.

I was taught to double-clutch on the farm trucks we had when I was a kid. Gear Synchros were unheard of then - oldest truck we had was a 37 Chevy 5-ton with straight-toothed gears, and the newest was a 1951 Ford dump - and NONE of them had gear synchros - so double-clutching was a big deal just to get it smoothly into the next gear. All it did was, when you were passing neutral between gears you let the clutch out for a second to allow the gear train to come up to speed (which was usually faster than needed for the next upshift) and then depressed the clutch going out of neutral and pulling gently on the gearshift to let it slip into the next gear when your gear speeds matched.

Of course, as a kid you quickly realize that it'll go from gear to gear just by matching the right engine RPM from neutral for the gear you want, and you never need the clutch except for starting out in first (sounds like Alan!), so we did that whenever no one was watching. If it's done right, it can be very easy on both the clutch and transmission, but most of the time un-experienced people do it poorly, unnecessarily stressing things and then lunch something causing $$$ to fly out the window.

As transmission and synchro designs improved, the need for double clutching went away, and doing so on todays' transmissions is un-necessary (and takes more time per shift and more wear on the clutch linkage).

I always felt funny trying clutch-less shifts on VW transmissions, as they tend to make un-natural noises when you miss a shift that way and I didn't want to break something. Maybe they could take it, but why dance with disaster?

Trivia - Paddy Hopkirk?

Ooh! Ooh!

The London to Sydney rally guy, right?

Aw, the lost art of double clutching! Once owned a '62 Corvette with a THREE speed transmission (Hey, I bought it used and it SURE wasn't mistreated). First gear was a typical non-synchro. Only way to get back into first after you atart moving is to double clutch. Done properly it is a very smooth transition between gears, with no sudden lurch or change in road speed as the clutch is finally released. Cold sober it was a highly unpredictable outcome. After a few beers on Friday night, I never had any problems. Analyzing this, I finally swapped out the three speed for a fourspeed Muncie for $150. It was a bolt-in swap, done in on home made wood ramps, in a garage heated by a pot belly stove in the middle of a Detroit winter. Those were the days my friends . . .

Paddy Hopkirk - good call, Chris!

Great friend of John Cooper of Nottingham (or was it Sherwood, back then?) builder of the infamous and well-neigh unbeatable Mini Cooper "S" ralley machines.

Seems like every picture taken of Paddy in his Mini during a Ralley showed him with this awesome grin - like he was in the best place in the Universe!

I think he also held the record for the London-to-Monte Carlo race for a long time, too.

so on my truck, this is why if i try to shift to quickly, being a truck tranny and all, its not always so nice to let the shifter into the next gear as fast as id like, even with the clutch pressed in fully. all about the synchros eh? Always learnin.

Nic:

Well, obviously you can DO it, (push it quickly into the next gear, that is), but all you're doing is making the synchros spin that next gear up all that much faster to make the about-to-mesh gears attain the same speed before you can easily slip them together.

Now, someone with more tranny-rebuilding experience than I can explain exactly what that does to the synchro gears, but my guess is that forcing a fast shift all the time would wear the synchros prematurely causing a tranny rebuild sooner, rather than later.

i try not to speed/power shift the truck, though it does probably have about 360 ft/lbs of torque and about 330hp :) which makes it fun to drive like that every once and a while... I just have to remember i can pull the gears as hard or quick as the Porsche.

guess i wont be double clutching the porsche and wont be speed shifting the truck... good ol camaro - damn automatics :)

I still don't quite follow the clutch transition to Paddy Hopkirk. Did he complete a few races without a working clutch, forcing him to do clutchless shifts or something?

I was thinking "random" on that one myself... someone draw the connection for those of us who dont have enough free time (or years under our belts) to memorize such useless, er, i mean, interesting information :)