A7 HALF SHAFTS

I Found the following in "Motor Sport" November 1966:

Congratulations to the Austin 7 and crews on their U.K to Australia and London-to-Tasmania trips. I note Horsbrough and Card had more than their share of half-shaft trouble and as it is common to these wonderful little cars a word on the subject would not be out of place. The major cause of half-shaft failure is badly fitting hubs and keys and I find the best way to fit these components is as follows :
Lap the hub on the shaft using valve grinding paste until the hub can be moved round the shaft steadily showing that high spots have been removed. Clean off paste and fit the hub to the shaft without the key and tighten up hard. Note the position of the nut, i.e., count the threads on the half-shaft showing and mark top flat or corner of the nut. Remove hub, fit the key and tighten up; the nut should go on the same distance as without the key. If the nut will not go on so far, the hub is riding on the key and that is the cause of the failures. To remedy, file the key until the nut will go fully home. This will need several trials; file only a bit from the key each time where it has been marked.
When finally assembling, if you find that the cotter-pin will not go in, do not slacken off a fraction but remove the nut and file a bit off, so that when fully tightened, the cotter will slide in. A useful tip is to mark the end of the shaft in line with the cotter hole.
Sometimes, when the hub and shaft are very worn and further metal has been removed by grinding, you find that the whole axle is locked due to the fact that the half-shaft gear has been pulled up hard on to the diff. cage. Do not worry, however, as a tapered sleeve shim can easily be made from bending round a piece of thin copper or even aluminium from a cigar tube or pastille box and cutting to size with ordinary scissors. After fitting this shim, the nut should be tightened after 5, 25, 50 and 100 miles or until it will tighten no further, showing that the shim is fully bedded in. Even without the shim, the nut should be checked after a few miles, and again, if it could be tightened.
One can, of course, drive an Austin 7 with a broken half-shaft, provided the broken end is pushed in to lock the differential and a wheel nut used as a distance piece to stop it working back.
I have driven my Austin daily for over nine years and leave the Jaguar at home for the wife. BRIAN R. HARFIELD.

 reply from Dave Wilcox:

As a 'lurker' who reads the mail of 'British Cars' etc but does not comment, your contribution re half shafts prompts me to respond for I am reminded that some years ago one Stuart Rolt gave a talk about back axles to a monthly meeting of the Pre-War Austin Seven Club. Amongst the many useful tips he suggested that the Woodruff key was in actual fact unnecessary since a properly assembled hub to half shaft was perfectly useable provided that it was tight. He validated his idea by claiming to have driven cars so prepared. Personally, I am not about to dive into the garage and whip the keys from my axle. Austins provided them and with the aforesaid proviso of proper preparation there they will stay. On a slight tangent but still vis a vis axles, I split the axle of my 1929 chummy some 18 months ago purely to examine its condition which was unknown when I bought the car. On each half shaft there was stamped a number which also appeared on the Woodruff key and the outer hub. These numbers were specific to each side and the examination confirmed that hubs keys and shafts matched. One therefore presumes that all items are original to the axle and unless this had been changed, also the car.  Condition of the keyways was good so it proves the point that if looked after you don't need to fix it, just have a peek every 69 years or so!!

Dave Wilcox

<Wilcox@seven.netkonect.co.uk>

With many thanks to John and Dave for this enlightening debate—Ed.