IN THE GARAGE

A series of articles from the experienced Austin Seven mechanics

at GM AUTO SERVICES tel: 01202-683848

Article Number 1 - The Need For Regular Servicing:

In these day of modern motor cars, we have got so used to not checking oil levels and not having to grease parts or lie underneath checking things, that I thought a timely reminder may be in order for the "good health " of your Seven.   The oil levels in the engine should be checked before every run as well as the radiator.  Every couple of months the rear axle and gearbox levels should be checked along with greasing the various grease nipples.  As many members only use their cars on the odd club run these maintenance jobs tend to get overlooked. This can prove very expensive;  crown wheel and pinions are getting very hard to find secondhand, and very expensive new, if you are lucky enough to find one.  Gearbox repairs and all bearings are now expensive.  A complete set of axle bearings recently cost £140 plus the cost of a replacement crown wheel and pinion plus labour.  So you see, half an hour checking levels and greasing up can save a lot of money and also a lot of rare spare parts.

Article Number 2 - Grease Nipples

So often do we see cars with a mixture of old original and modern grease nipples. With this combination, a quick grease-up becomes a real pain because two grease guns need to be employed to do the job properly and evidence has shown that because of this it is rarely done correctly.  The answer is obvious really, either fit original style nipples throughout and use an original gun or, our preference, fit modern nipples all round. You can fit either straight ones or angled to suit your needs and these are readily available from either the Seven Workshop or from club member Willie McKenzie at ARP Services. Note: sometimes the front spring shackles may have smaller ones fitted so check first. All you then need to do is visit your decent local motor accessory shop and treat yourself to a modern grease gun.  Obviously with parts becoming harder to find it makes sense to keep your vehicle regularly maintained.  If you are a real purist you could even remove your old nipple, screw in a modern one, grease and replace with existing!

Article Number 3 - Reconditioning Ruby Propshafts

The Hardy Spicer joint bearings, after many years service, 70 odd if original, will have become very loose and worn.  This is easily checked by twisting and noting any play between the two parts of the U.J.   If play is evident, new joints are required and they can be obtained from Willie McKenzie or Seven Workshop.  There are two joints on each shaft.
Shaft removal from the car is quite straight forward.  Just undo the four bolts on the gearbox flange and the four on the torque tube flange and the shaft will come away.
With the shaft on the bench, unscrew the aluminium flange holding the sliding spine and pull the splines away releasing the front U.J. from the main shaft.  This short section is probably the best to tackle first as it is usually covered in grease and oil and therefore easier to dismantle.  You will notice circlips located in each of the four knuckles of the joint.
Remove all of these using circlip pliers.  Then, with the joint held firmly in the vice, insert a drift into one of the 4 holes and with a heavy hammer drive the old bearing as far as it will go.  The bearing on the opposing side will be driven out about half an inch, remove the joint from the vice and clamp this half inch into the vice and you will find it will either twist out or can be tapped out by hitting the body of the joint.   Drive the cross spider back until the opposing joint shows half an inch and repeat the process.  Remove the other two in the same way and then the centre spider can be removed.  Clean parts thoroughly before starting the replacement.
Carefully pull off all four caps containing the needle rollers from the new spider, fit the spider into the holes in the shaft and gently press the caps back through the shaft onto the spider using the vice as a press or tapping gently with a hammer, making sure the spider enters the caps on both sides by sliding it back and forth to ensure it does not jam (this could cause the needle rollers to fall out of position).  When the caps are flush with the yoke of the shaft, drive them on one at a time and refit the new circlips.  I have found that these new circlips often need filing down as their diameter is a fraction too large (note: do not add extra grease to the caps as this will cause them not to push home fully).  Check that the circlips are located firmly in their slots.  Job done.   Repeat the procedure on the other joint.

Article Number 4 - Front axles

When deciding on a replacement front axle, check that the king pin eyes are not worn oval. The pin should be a tight fit, also check that the axle is not bent or twisted. You can change from l inch to l 1/4 inch brake shoes without any other modifications. If you find that, on replacing the drums, the brakes bind on hard, try chamfering the edge of the shoes nearest to the back plates as it is possible in some cases that there is a wear ridge in the drum. Regarding the shock absorber modification, handling can be improved by fixing one side of the shock absorber directly on to the pin on the axle. Remove one side (either side will do) and remove the aluminium link, cut the link in half, drill out one side of the pair of blades to 3/4" and, using the half link as a spacer with a new rubber brush, refit onto the pin in the axle using a steel washer to pinch the rubber bush tight. This mod. prevents any sideways movement of the axle in relation to the spring.

Article Number 5 - A7 Carburettors

The Austin 10 carb won’t work properly on the Seven as the choke tube (the size of the barrel) is larger on the 10.  The size of the intake tube is critical in the pick-up of fuel from the jets.  Petrol is sucked into the choke tube by the venturi action of the intake of air through the carburettor which has to be at the correct speed for the jets to function properly.  The air is sucked into the carburettor by the pistons so there has to be a balance between bore size and choke tube size to achieve the correct speed of incoming air.