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+--- Thread: Gear crunch - 1st and 2nd (/showthread.php?tid=7641)
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Gear crunch - 1st and 2nd - emleyj - 21-06-2022
I’m new to Seven (but not classic car) ownership. I have a 1935 Ruby.
I understand the requirement for double de-clutching to facilitate smooth gear changes and to try and change gear at the correct speed.
I am generally able to get a smooth change up and down between 3 and 4.
However from idle I struggle to engage 1st, 2nd and reverse no matter how many times I depress the clutch. More often than not there’s a crunch, but not always. It’s the same story going from 1st to 2nd (though it’s not as bad, I think I’ve figured the best speed and double de-clutch technique) and when going down from 3rd to 2nd (again not generally as bad as when the car is idling).
Any advice on what I could do to improve this would be appreciated. I’m not sure where to start.
RE: Gear crunch - 1st and 2nd - Reckless Rat - 21-06-2022
There is no synchromesh on 1st gear so trying to engage it on the move is difficult. I just don't bother and always set off in 2nd unless the hill is steep. Some 4 speed boxes also didn't have synchromesh on 2nd gear, just on 3rd and top. Your car might have one of those fitted but the only way to be sure is to take the top off. Obviously if it is then you're always going to have to double up and down changes to and from 2nd. Engaging 1st or reverse is easier if the tick over speed is correct and there's no clutch drag.
Gearbox should contain engine oil not the thicker gearbox oil.
RE: Gear crunch - 1st and 2nd - Ivor Hawkins - 21-06-2022
First gear on your Ruby is really an emergency low as Reckers has said, on my box I never use it and double declutch down the box without a problem, however my problem is a crunch changing up from third to fourth...I think the solution is what was recommended by my dear old dad, up to optimum revs in third, dip the clutch, get a Senior Service out of the packet, select neutral, light your fag, depress the clutch, take a puff then select top.
I would have tried before now, but I can’t find a shop that sells Seniors...
RE: Gear crunch - 1st and 2nd - emleyj - 21-06-2022
Thanks for the replies. I’ve just changed the engine oil (20W50). My next job should be changing the gearbox oil and I’ll use the same stuff.
Thanks for the tips on keeping 1st for steep incline starts only. I’ll try just using 2nd.
My ear tells me that it’s idling too quickly. I did try slowing the idle rate but found when the throttle was blipped the car just wanted to cut out. The quicker idle stopped that. I guess that could be fuel mixture related? Points look nice and clean, haven’t checked the plugs. Float chamber jets are clear.
As for the senior service tip, I’ll need to take up smoking! ?
RE: Gear crunch - 1st and 2nd - Ivor Hawkins - 21-06-2022
No need to take up smoking Emley! but you might want to give the jets in your carb a thorough clean, you might find that will sort your slow running problem.
RE: Gear crunch - 1st and 2nd - John Cornforth - 21-06-2022
Hi
If you get a crunch when stationary even after depressing the clutch and waiting a few seconds, it's a sign that the input shaft of the gearbox is still turning. This normally means that the clutch isn't completely disengaging (clutch drag). It only takes a tiny amount of drag to overcome the friction of the input shaft and keep it turning. Fast idle will exacerbate this but isn't the root cause.
If the clutch pedal downward travel is being limited by contacting the floor, you could try moving the pedal lever position on the clutch operating shaft (it's held by a pinch bolt) so as to get a little more disengagement.
RE: Gear crunch - 1st and 2nd - Duncan Grimmond - 21-06-2022
I tend to double de-clutch both going up and down. Allowing the gear and engine speeds to match really makes a difference in achieving a smooth gear change (after you have done all other adjustments).
RE: Gear crunch - 1st and 2nd - Howard Wright - 21-06-2022
(21-06-2022, 07:40 PM)Duncan Grimmond Wrote: I tend to double de-clutch both going up and down. Allowing the gear and engine speeds to match really makes a difference in achieving a smooth gear change (after you have done all other adjustments).
Hi All
I agree with Duncan, I make ddc on the way up simple by clutch, out of gear, clutch then in gear rather than trying to match the engine speed with the throttle. Works for me.
Cheers
Howard
RE: Gear crunch - 1st and 2nd - Reckless Rat - 21-06-2022
Don't overfill the gearbox. Fill it to the BOTTOM of the threads on the filler plug hole.
RE: Gear crunch - 1st and 2nd - emleyj - 21-06-2022
Yes, this is exactly what’s happening. Even after waiting a few seconds there’s usually still a crunch selecting gear from stationary.
I’ll have a look and see if this adjustment is covered in my Austin Seven manual. In case it’s not, where is the pinch bolt located?
Comments about double declutching noted, thanks. Same for gearbox oil fill level - bottom of the threads on filler plug hole is the same as on my other classic.