Gear crunch - 1st and 2nd

[Reckless Rat]

Base of the clutch pedal onto the shaft that goes through the bell housing. There is a slot cut in the end of the shaft so you can hold it still with a big screwdriver while you position the pedal, but ideally it's a two person job. One to hold the release bearing against the fingers (through the hole in the bell housing and another pair of hands to loosen and retighten the pinchbolt on the pedal.

[Lowbarn]

What happens if your gear filling hole is on the top of the case?
Can I use the engine dipstick?
Richard

[Nick Turley]

I think that it is most likely that your clutch is not clearing properly and there for requires adjustment and possible overhaul.
It is a gearbox out job I am afraid. 
A lot of Austin Sevens suffer from the same problem due to clutches not being set up correctly on assembly.
There is a certain amount of bad information around on this issue.
If you want further advice/help on this send me a mail and I will do my best to help as you are new to Sevens.

[AustinWood]

If the filler is on the top then it's a three-speed gearbox. The engine dipstick works for the gearbox.

[Lowbarn]

Thanks Jim.
It is a three speed.
Regarding gear changes it’s taken me 12 months to learn how to change up from 1st to 2nd. 2nd to 3rd is ok.
As for changing down! I daren't. I will perhaps try giving the whole operation more time as previously suggested.
Richard.

[Reckless Rat]

On a crash box, like the 3 speed and the early 4 speed, when you change gear you're actually moving a straight cut gear into mesh with another one. It only happens if the two are rotating at the same speed (ie synchronised) - in the later synchromesh gearboxes this is done for you by cone clutches, which allow the change to be made without having to match engine to road speed.

When changing up, you have to wait for the engine speed to drop to what it would be at the same speed in the next gear. The A7 has a heavy flywheel and it takes time for it to slow down. Try counting out loud "One, one thousand - neutral, two, one thousand, gear" and you'll not be far off. Same for a down change, but this time you have to increase the engine speed to match the road speed. Don't rush it. If the speeds of the gears are matched it will drop in as smooth as silk. If not you're making steel dust.

It's really hard to ddc into 1st at anything above walking pace without a crunch. Better just to stop.

[John Cornforth]

The comments re double declutching are all very relevant when on the move. However, my understanding of the original post is that there was difficulty engaging gears when stationary and idling.

In this situation the propshaft and output shaft aren't turning, and the input (first motion) shaft and layshaft shouldn't be turning either, assuming the clutch is fully disengaged and you have waited a few seconds for any motion to stop. The idling speed and the gearbox oil level and grade will determine how long you have to wait.

You now have the situation where the gear "speeds" are matched, i.e. they are both zero. Most of the time it should now be possible to move the gear lever and select any gear. Occasionally you might hit an unlucky spot where the teeth on the relevant two gears (or the dogs in the case of top gear) just happen to be almost in line and won't slide into mesh, in which case you need to bring the clutch pedal up and down briefly and wait again for input shaft motion to cease. With luck the gear teeth will now be in a better position to allow meshing. If you hear crunching as the gears are selected when stationary, it means that one gear is still turning, normally due to the clutch not fully disengaging i.e. clutch drag.

This article might be of interest: http://www.da7c.co.uk/technical_torque_a...arbox.html

[Colin Wilks]

emleyj, if Nick Turley has offered to help you, this is an offer you would be crazy not to pursue. I got into Sevens about four years ago and Nick has been a huge help to me throughout.

[emleyj]

Thanks very much for the further replies. It’s great to see these forums so active with helpful replies and offers of assistance. I’ll drop Nick a message.

[emleyj]

Just an update to say I think my own inexperience with Sevens contributed greatly to this issue. Having practiced slower gear changes, when to shift up and down (especially in relation to hills) and using a 4s pause between engaging the clutch and gear selection when at a pause. It’s also surprising just how versatile third gear is!

Whilst I haven’t quite perfected the driving technique it’s a much improved situation.