Hi Gents - do these mouse trap springs stay on the clutch fingers when putting the gearbox back or should all three be removed.



Thanks
Bob

The mousetrap springs remain fitted to the toggles Bob.

In that case I'll prepare for battle tomorrow to try and install it. Thanks for the speedy reply Ruairidh

You will find it a good deal easier to reinstall if you remove the clutch plate from the flywheel and clamp it shut with three evenly spaced g-clamps. Use long nose plyers to feed the tails of the springs back into the holes, then reinstall back onto the flywheel.

Or failing Ruairidh's method, get hold of three 2 1/2" x1/4" sets screws and three nuts , evenly space them around the plate and compress the springs by holding the head of the set screw and tightening the the nuts, once compressed enough fit the normal bolts to the remaining three holes, remove the set screws and fit the remaining bolts . This method can be used whilst the fly wheel is still in place. Doug Woodrow's idea not mine.
Derek

Location: Basingstoke

And don't forget to line up the 'blind' splines otherwise the gearbox won't mate with the engine. It's an OK job with the two out of the car but can be a bit of b*gger if the engine is in situ.

Location: Hertfordshire

The blind spline can make refitting the gear box difficult. When I last did this a few years ago, I seem to remember putting the box in gear and marking up the flange at the back of the gear box with the orientation of the blind spine. When it got knocked out of position during fitting, I could then set it back to where I knew it needed to be to slide on.
Hope this helps.
Colin

My index finger fits exactly into the splined hole and by jamming it in I can see the imprint of the blind spline and turn it to line up with the blind spline on the spigot...works every time!

Sorry to go off thread, but can anyone explain why there's a blind spline anyway?

Location: Near Bicester

Location: As far east in Kent as you can get

In "olden days" I don't think it was unique to the Austin seven , but why it was done is a mystery .

Merv

Location: New Forest

I think the one in my RN must be an after market one ,as it does not have a blind spline.

We've covered the Blind-spline subject before on this Forum. As I wrote previously, the official Austin Company explanation was that it is there "for convenience", which in my book is the opposite of real life. Cheers, Bill

Location: Mount Eliza, Australia

Bob,

undo that bolt that is clamping the pedal to its shaft and rotate it towards the back of the car, then tighten up the bolt (tight).

Dunno how to tell you this, but as far as I know you can only adjust the clutch travel by taking the clutch assembly out and adjusting the operating arms with an amendment to Austins design which includes drilling and tapping the area at the fulcrum of the toggles. And inserting some grub screws. The measurements from the working face of a Newton Bennett clutch is 1 1/4" and a Borg and Beck is 1 5/16". Drill a hole in each of the fulcrum points using a tapping drill for 1/4" NSF thread . Insert socket head screws from the lining side and adjust to measurements above, having put thread lock on the threads.
Hope this makes sense .
Derek

Location: Basingstoke

If my suggestion does nothing to help the clutch, Derek is correct!

Location: Near Bicester

There's a great article on adjusting clutch on the Cornish Austin 7 Club website: http://www.austin7.org/Technical%20Articles/Clutch%20Pedal%20Adjustment/

I have used a lump of wood behind the oiler in the past!!

Location: North West Hampshire

Linky

Ian Mc.

Location: Shropshire

Location: Fed up hosing mud off the dogs.

At the risk of being more boring than usual.........
Lining up the clutch plate is made much easier by just nipping the pressure plate set screws on the first thread then offering the gearbox up (yes a finger up the hole to find the blind spline, if necessary with the box in top gear and the propshaft flange marked at top with Tippex marking fluid to match the spline). If the blind spline is slightly out you can a) see where it should be by the Tippex mark and b) alter it easily as you only need to hold the box lightly against the end of the spline. Once the box is mated you can nip up the set screws a bit. I do this with the engine half in and half out of the car with the nose piece sitting on a one gallon oil can on the floor. (The petrol pump will be about where the exhaust pipe flange is) Once I've bolted the gearbox to the engine I fully tighten the clutch plate set screws, tie the clutch pedal fully forward to the engine oil filler pipe and lift the engine fully in. I've never had a problem. You can adjust the clutch pedal with the assembly in situ by using a piece of flat bar about 8" long curved (like a panel-beating spoon) to hold the release bearing where you want it before tightening the clutch pedal bolt. It works on the later cars. Thank goodness there was no blind spline on the earlier ones! Did the blind spline come in in '34 or was it earlier?
Steve

Location: Soggy Somerset

Steve - I'd have thought when the 4-speed box was first introduced = nearer 1932 than 1934? Cheers, Bill

Location: Mount Eliza, (not a mountain but hilly, overlooking the Bay) Australia

My 1929 engined 1928 Chummy with a 3 speed box had the blind spline and I can remember cursing loudly at the umpteenth attempt at assembly. I think I have pictures of it somewhere.

Location: Near M1 Jtn 28

As with Brian, my 1929 coil engine and 3 speed box also have the blind spline.

EDITED: That actually may, or may not be true. The clutch plate definately has the blind spline - the engine is under the bench and I have just checked (but, of course, the clutch plate might well not be the original one to the engine); I can't remember about the gearbox - that is currently in the car with a different engine

Ian Mc.

Location: Shropshire

The deciding factor is whether the gearbox 1st motion shaft has a blind female spline or not. If it hasnt, then both clutch plates (blind spline/non blind spline) will fit. If the gear box does have the blind spline then only the clutch plate with a blind spline will fit it.

Just re-read that and I think it makes sense!!

Location: Farnham

David,

" The deciding factor is whether the gearbox 1st motion shaft has a blind female spline or not. If it hasnt, then both clutch plates (blind spline/non blind spline) will fit. If the gear box does have the blind spline then only the clutch plate with a blind spline will fit it."


I think you mean it the other way-

The deciding factor is whether the gearbox 1st motion shaft has a blind female spline or not. If it has, then both clutch plates (blind spline/non blind spline) will fit. If the clutch plate does have the blind (male) spline then only the gearbox with a blind (female) spline will fit it.

Tony.

Location: Melbourne, Australia

Sorry guys but, I don't think I agree with either statement. The interior of the 1st motion shaft would have a MALE blind spline, if it had one at all, in order to match the FEMALE blind spline on the exterior of the centre spigot on the clutch plate.
i.e. the cluch plate spigot has a missing spline- in effect a groove; the input shaft has a double width spline to mate with that groove.

If the gearbox does NOT have the blind MALE spline either clutch plate centre will fit; if the gearbox DOES have the blind MALE spline only the clutch plate centre with the blind FEMALE spline will enter it.

Or are we all saying the same thing but in different ways??

Ian Mc.

Location: Shropshire

Location: United Kingdom

Cheers Steve.

Ian Mc.

Location: Shropshire

I'll go back in the shed and check - this time with my glasses on!

Location: Farnham

I think I have at last fathomed out the purposes of the blind spline.

It is there to cause immense frustration, much debate, a measure of confusion, and the occasional bit of work for the local fire brigade in releasing trapped fingers from holes up which they should probably not be put.

In short, another example of the perfect functionality of all things Austin 7.

p.s. I can't tell you what a joy it is to hear that I am not the only one overcome with Tourette's when trying to put engine and gearbox together.

Location: Moist Hertfordshire

Location: Farnham

Crikey

To set the clutch up properly all you need to do is to bend those levers to the required position.

With my 3speed car I set them with a touch of heat so that when you put a straight edge over the bll housing I can just fit a 6mm plate between the toggle end and the straight edge. I use this as a gauge.

Not sure what it is for these later cars, but I would be interested as its a job I'm going to be doing one soon. And it would save a bit of measuring to know.

If the toggles are not set up properly, the clutch will either slip, or not disengage properly, or even the toggles hit the taper pins on the clutch pedal shaft on the gearbox when you press the pedal.

Setting the pedal is a simple affair. Turn the shaft so that the bearing touches the toggles, and then clamp the pedal where you want it. I was always taught to saw a slot in the other end of the clutch pedal shaft (before assembly) so you can use a screwdriver to turn it when you do this.

As for the splines, I've never ever had a problem with this, but I do always fit the gearbox to the engine before putting it in, not while putting it in. All you need to do is have the gearbox in gear, do your best to aim, and if your out a bit turn one way or the other on the gearbox output untill it drops in. It always pays to try the clutch plate spline in the gearbox spline before assembly of the clutch. If its too stiff it upsets the clutch operation and it will drag, it needs to be a nice fit.

David,

So -

"The deciding factor is whether the gearbox 1st motion shaft has a blind female spline or not. If it hasnt, then both clutch plates (blind spline/non blind spline) will fit. If the gear box does have the blind spline then only the clutch plate with a blind spline will fit it."

Should read-

The deciding factor is whether the gearbox 1st motion shaft has a blind male (not female)spline or not. If it hasn't, then both clutch plates (blind spline/non blind spline) will fit. If the gear box does have the blind (male) spline then only the clutch plate with a blind (female) spline will fit it.

Never having had anything to do with this very strange Austin 7 quirk I will take my bike and go.

Tony.

Location: Melbourne, Australia

Hedd,

My understanding of the difference between the three speed clutch throwout assembly and the later four speed clutch throwout assembly is that the first has a plain ball thrust bearing which needs to be held together at all times, so the clutch levers press the unit forward onto the three fingers which are 'loose', whereas the later throwout assembly has an angular contact ball bearing which holds together under no load, so the levers and throwout assembly are kept out of engagement by springs and the mousetrap springs hold the three clutch levers back.
Thus the early clutch has the bearing always runnung, the late only runs when disengaging the clutch.

As you note the setting of the fingers is critical and all must be in the same plane in the three speed box arrangement, or the clutch pedal jumps around alarmingly

Tony.

Location: Melbourne, Australia