Lee and I have opposite theories about double-clutching on down gear changes. This is a neutral discussion, I just want to know what everyone else thinks about the topic..
Cheers 😎
[Edited on 20-11-2004 by oval TOFU]
...and Robert's ya father's brother...
If it means a smoother downshift then why not?
If you enjoy fitting thrust bearings it's worth it. :thumb
BAJA NOW FITTED WITH A FULL FLYING REBUILD
If you prefer fitting gearbox bearings instead, don't do it.
on a vw or a semi?
some people are like slinky's
they have no useful purpose
but they are fun to watch
when you push them down the stairs
i thought thats what syncromesh is for 🙂
Jon
Have to do it quite a bit...gearbox worn out 🙁 so beneficial as I guess its a lot better than crunching in the gears...
Heidi - 1960 White Beetle
'65 Kiwi Ghia
Can everyone elaborate a bit on thier comments? - thrust bearing and gearbox bearing replacement? (I know thrust bearing would be easier to replace!)
buzzbug its manual
che Castro From my understanding, doesn't it reduce the wear on the syncros as they don't have to 'work' as much to match the larger differences of speed the gears are rotating?
...and Robert's ya father's brother...
The thrust bearing slides over the Gear Box input shaft. When you use the Clutch, the fork moves the bearing into contact with the Clutch housing and it releases the grip on the Clutch Plate.
So every time you use the Clutch the Bearing has to do some work.
They should last as long or longer then the Clutch, but I always replace them when I replace a Clutch.
In all honesty Double Clutching shouldn't really hurt anything.
As for not Double Clutching hurting the Bearings in the Gear Box. :duh I don't think so, it would only hurt the Gears and Synchros if there not meshing properly and there being crunched together.
But I do know a Young Driver who has destroyed two thrust Bearings. I don't want to name him but he has Numbers and stripes on his Car. :thumb
BAJA NOW FITTED WITH A FULL FLYING REBUILD
I do it out of necessity.
Going from third to second is next to impossible without it. The gearbox crunches violently. Same with second to first.
The Vw gearbox will even let you change without using the clutch.
Just pick the right revs
Warren
Warrenm wrote:The Vw gearbox will even let you change without using the clutch.
Just pick the right revs
Warren
any gearbox will except maybe an FSM niki...
"Tell him 'We've already got one'"
always.
that's how i was taught to drive and i love the sound of it. especially if you go from 5th to 2nd in hard braking 😀😀 (in a 97golf)
plus with a gearbox that requires a knee hooked over it to keep it in 4th (64 notch).. double clutching just makes it more interesting 😀
zac
MOB: 0423890217
Mines a bit of a yes and no. If i am putting around i usually just down shift as normal. If i am into it a little and am downshifting hard i will rev match and double clutch to save syncros. My gearbox is quite good for an original. Only problem. 2nd to 3rd quickly creates a little crunch, and 2nd gear syncro wont hold in gear under high revs. (if i am in 2nd and floor it to 40mph and back off, it'll knock back into neutral. If i am putting around it behaves nice. Its old. Its tempremental. Doubleclutching and rev matching certainly sounds better if ya racing around thou. Especially if u got an audience and your coming into a nice roundabout or a set of lights :thumb Thats my 2 bucks.
Its only nessasary if you have a crash box, or worn syncro's. If you have a syncro box, why bother. VW made the later box's syncro for a reason, so not so good manual drivers would have an easier time of it and not destroy their gearbox! In my old 56 you sometimes have to change into first (non syncro) on a steep incline, I do it then and then only!
Rob...😎
Boxer Power
Member of DMLRK.....Die Mittler Lebuns Resto Komeradschaft
nah. i'm a young driver and when in town...if i rev in 2nd then drop it..i can make the car backfrire very nicely. then as you come to the lights sounding like a beefy harley..it just attracts looks.
so always..it's still great fun in the 97golf too.
MOB: 0423890217
I am not sure if some understand what double declutching is.
Perhaps the ones that drop into 2nd and sound like a Harley could explain what they do.
Warren
say you're in 4th gear...
and you go to change down to third (there are multiple ways of doing this...)
you press the clutch in..blip the throttle..and then slot the gearshift into 3rd 'predicting' the revs beforehand. ie..do the syncros job for it.
makes for smoother downshifts and better control i think.
zac
MOB: 0423890217
zac_smits wrote:say you're in 4th gear...
and you go to change down to third (there are multiple ways of doing this...)
you press the clutch in..blip the throttle..and then slot the gearshift into 3rd 'predicting' the revs beforehand. ie..do the syncros job for it.
makes for smoother downshifts and better control i think.
zac
Double declutching:
You are in 4th and wish to change down- you put in clutch- shift to neutral-let clutch out- push clutch in- then shift to 3rd.
This allowed time for gear sets to match speed on crash boxes.
It is not double de clutching unless the clutch pedal is depressed twice..
Warren
[Edited on 21-11-2004 by Warrenm]
yeh i missed a line there...
and you just push the clutch in far enough to pop it out of gear..
but i still blip the throttle before pressing the clutch again
MOB: 0423890217
Thats why it is a waste of time on a syncro box, thats what their for! unless the syncro's are worn and not working. I have heard that double clutching on a syncro box accellerates the wear on the syncro mechanisims, is this so?
Rob....😎
Boxer Power
Member of DMLRK.....Die Mittler Lebuns Resto Komeradschaft
wouldn't have a clue mate
MOB: 0423890217
I won't double clutch everytime I downshift, usually only when I skip a gear (ie:4th to 2nd). If I'm putting around, as Blue_72 says, I'll just downshift normally. Personal preference and 'if you can be bothered' I suppose...
Splitting hairs now: wouldn't it reduce some wear on the clutch as well since it doensn't have to press against the pressure plate (or driven plate or whichever) at such large different rates of rotation?
[Edited on 21-11-2004 by oval TOFU]
...and Robert's ya father's brother...
Thats right, but if you get it wrong and clash the gears, whats more expencive to repair, a clutch or the gearbox?
Rob...😎
Boxer Power
Member of DMLRK.....Die Mittler Lebuns Resto Komeradschaft
Robo wrote:Thats why it is a waste of time on a syncro box, thats what their for! unless the syncro's are worn and not working. I have heard that double clutching on a syncro box accellerates the wear on the syncro mechanisims, is this so?
Rob....😎
Yes it "spins" synchros at higher speed and causes additional wear.
Warren
Warrenm wrote:Robo wrote:Thats why it is a waste of time on a syncro box, thats what their for! unless the syncro's are worn and not working. I have heard that double clutching on a syncro box accellerates the wear on the syncro mechanisims, is this so?
Rob....😎
Yes it "spins" synchros at higher speed and causes additional wear.
Warren
Aren't the syncros spinning whenever the gearbox is in motion anyway?
...and Robert's ya father's brother...
