Hello all, hope you wont mind a newbie asking a question.

I've bought a baby austin, not had it long, but bought it because it had just had an engine rebuild, and a new MOT.

I've not done much with it, just a few short trips into town and back, probably 30odd miles since I bought it. Ive encountered two problems witch seem related. On one trip at about 35-40 mph in top gear (3rd), there was a funny wizzing sound from the gearbox flywheel sort of area, when I slowed up it stopped. On another run again at the same sort of speed in 3rd I got a click followed by the same noise, then as I slowed up it turned into a knocking, the knocking carried on even with the gearbox in neutral, also on tickover once I had stopped it seemed to keep time with the engine. I switched off, started up again and it had gone. The noise came from the flywheel sort of area again. it didnt sound like an engine knock. It had about 3lbs pressure, but I'm told this is about normal when warmed up?

Any ideas, I thought the flywheel could be loose, but with the cover off it seems tight and doesnt wobble or anything. Someone said it could the clutch bearing as they turn all the time (?) on my car (?), could this be the culprit?. I oiled it down a tube and it didnt happen again but I'm not sure, or could it be the gearbox, it seems a bit noisy, there is a definate chipped tooth in top gear. I've not had the problem in any other gear, and Im sure I've had more revs on in 2nd than when doing 35 in 3rd.

Sorry but im a bit stuck!

Welcome to the world of A7s. There are plenty around and you will not be short of helpful contacts to solve A7 problems. The knocking you describe could well be the clutch toggle arms striking one or both of the cotters securing the clutch withdrawal levers to the cross-shaft. This is the shaft which rotates when you depress the clutch pedal. There is not much clearance in this area so it is important to check on assembly that the cotters do not protrude unduly.
It looks as though the remedy (in any event) is to separate gearbox from engine and inspect the cotters for impact damage! If this is found, file off the damaged area , plus some margin, from the cotter(s) and ensure clearance by measuring the distance to the cotters from the bell-housing joint and, similarly the distance from the toggles to this common face. The difference will indicate the clearance.
The good news is that it is unlikely that any expensive damage will have ocurred! The really good news could be that if the noise has gone it is because all the "surplus" metal has been "machined!!" off and you now have clearance. If the noise has gone I would leave well alone! Let's see what others think!
If you are into a gearbox rebuild I recommend the manual by Doug Woodward. I expect details of this will be found on this site in the "Search" box.
Ron

Clonks and rattles are all part of the fun...unless serious!

I rebuilt my engine at the end of last year and on cranking came across a repetitive 'clunk' from around the flywheel area. Turning the engine slowly over on the starting handle, with the flywheel cover removed, showed that the flywheel was very slightly fouling a tiny casting 'lip' on the edge of the bellhousing - the rectangular opening under the flywheel cover. It was really loud and I thought the flywheel was loose but splitting gearbox from engine revealed no such problem. I filed a couple of mm off the lip and since then, touch wood, no problem. Might be worth taking your cover off and having a look... Good luck.

Nick

Would the clutch levers hitting the pins cause a intermittent knock? I'd have thought it would happen pretty much all the time. My noise only happened once and when the car was going fairly fast

I had the head break off a clutch plate bolt once, it made a short knocking noise as it was flung around the bell-housing, then clicked for a bit as the flywheel caught it every so often. It stopped eventually and disapeared out of the hole!

Check and see if all 6 bolt heads are still there by removing the flywheel cover.

Cheers

R

I agree with what you say Ben. It doesn't appear to be clutch lever pin trouble. If it was a one-off knock it sounds like a loose item in there, as suggested by Ruairidh, including the possibly of a washer, or some-such having been left hidden behind the flywheel during the rebuild. Moral is to get the flywheel cover tack bolted back on v soon after fitting the flywheel -especially if the job gets interrupted (as they always do!)
Ron

Having taken the cover off, and had a look (engine still in), it seems the levers are held in by the clutch bearing, the clutch bearing is held towards the engine by the clutch shaft on the gear box, that in turn is held forward by an external spring.

Say when going fast the vibration allowed the clutch shaft to let the pressure off the bearing, alowing it to vibrate towards the gear box, this would allow the levers to also move towards the gearbox, and the possibility of hitting something. This could be an intermittent thing couldnt it?

I'm going to have a drive tommorrow, get some miles on the clock, and see if it does it again. It hadnt knocked before, and hasnt done it since. If it does engine is likely coming out, your replies have given me some ideas what to look for when it is happening.

Say it was the engine what would cause an intermittent Knock like that?, could it be a little end?, it didnt sound like a big end and it was ok after.

The joys of vintage motoring

Ben,

little ends tend to tick when the engine in idling.

If it doesn't do it again then it may have just have been something picked up in the bell housing, which may well have gone by now!

If you start taking the engine apart looking for what it is you may cause more problems. Are you amember of an A7 club? Can you ask someone to listen to it and advise you??

Cheers

Ruairidh

did near on 15 miles yesterday on back lanes, no knock. Argh.....................................

Ben,

I would suggest you now enjoy your car and if the problem returns, deal with it then. Anything serious would, I am sure, have showed up over a 15 mile run.

Cheers

Ruairidh