Half Shaft replacement AG tourer 1932

[Terrytuned]

David for fitting lip seals see BA7C technical website for latest updates under axles oil leaks.

[Bob Culver]

Hi Jon E

If the keyway in axle is visibly distorted the axle will be markedly out of round. Attempt to restore entirely by lapping will likely ruin hub and draw the axle too far out. Distorted (and not!) keyways are usually cracked although with ideally fitted hub with tight fit at large end might not progress. For most the inconvenience and  effort of later failure and  replacement does not warrant the risk. If persisting nonetheless tailored keys can be filed from "silver steel" and hardened. As others have pointed out, ideally do nothing.

Hi Stuart
 
I am intrigued that you recover axles. The several remarkably battered ones I have (aftermarket, off wrecks) are very hard. Do you let down the temper or do all with carbide tools, including the screw cut? How do you cut the key?
I have a near new Australian Dufor long axle. Dufor made replacement parts for everything but quality seems questionable. It  is finished at outer end to the smaller dia. This has placed the key at the edge of the taper and so is cracked. As a matter of interest on original short thin axles, how much of the engaged taper was there inboard of the key? I wonder if the dia increase was to gain a little more critical space.

[Ian Williams]

Dufor appear to have made made some rather poor quality parts, I believe they were responsible for the glass king pins which caused a few problems in the 70's and 80's. We also shorten LWB half shafts to make SWB items, some may not know that it is possible to shorten early Big Seven ones to make new LWB.

[Robert Leigh]

I am sure that there is lots of good advice in what has already been said. I want to add a word of caution: I found an axle where the hub had been ground onto the halfshaft probably a number of times, requiring a washer under the halfshaft nut so that the split pin could be lined up satisfactorily. Also it seemed that the inner end had the pinion scraping the inside of the differential case, producing silvery bits in the oil! This shows that it can be worth replacing hub and half shaft, so that they are both at the original dimensions.

Robert Leigh

[JonE]

is anyone supplying new rear hubs, Robert?

[David.H]

Original poster returning to the topic! The hub came apart easily and the stub of the half shaft (with key) came with it. now the interesting bit!
The half shaft had been drilled and tapped and a piece (I think) of studding screwed into the half shaft to join the pieces! I won't be sure until I remove the other end of the shaft from the diff. The stud/bolt had snapped (Surprise, surprise!)
I will post pictures when I have the shaft out. The stub separated easily & the tapers & key/keyway were in good order.
Amazingly the bearing is perfect. No sign of seal nor gasket......
The nearside hub also came apart easily & seems to be in good condition.
Now to take the broken shaft out. I have a spare that I Hope may be the right pattern.....
D

[squeak]

  Sounds like another candidate for this collection of bodgers         https://www.pinterest.com/foreman87/austin-seven-bits-and-bobs/

[Stuart Giles]

Hi Stuart
 
I am intrigued that you recover axles. The several remarkably battered ones I have (aftermarket, off wrecks) are very hard. Do you let down the temper or do all with carbide tools, including the screw cut? How do you cut the key?

Hi Bob,
         I machined the shafts just as they came. Of course, it's possible that the factory's original temper may have been "let down" slightly by my having welded up the original keyway and allowing natural cooling before machining.

I use carbide insert tooling for pretty much everything nowadays, but the Austin factory shafts will machine OK with dead sharp HSS tool as long as speeds and feeds are reduced to suit. The Keyway in the shaft below was cut with a HSS Woodruffe cutter without any issues.

In the photo below, the shiny area you can see is where I blended out the factory's Brinell test witness mark with an abrasive disc; this is something I do on all Austin shafts now to get rid of this serious stress raiser. The halfshaft piece below from one of my cars failed straight across the Brinell witness mark.

[Bob Culver]

Thanks Stuart
 
Sevens are full of surprises. Fatigue cracks often curve around bruises and other areas of compression. It was this observation that lead to rolling, peining etc as a counter measure! 
I have never had an axle fail and all the terribly battered ones I have acquired would have still been “mobile “ , with none broken across. On one, key shaped chunks either side of the key have gone completely! Presumably many fail across , I guess more usually at the end of the key.
Screw cutting in a lathe is a chore for those not practised but presumably this is how you cut the threads.
 
I have mentioned before, but when my car was in everyday use a young apprentice a few doors away ran a terrible Ruby. He decided to venture far out of town and encountered problems. So he called at my fathers home where he knew there were tools to attend to a rear hub. The keyway was so wrecked he had trouble balancing the key in place to assemble. My father was somewhat  meticulous in matters mechanical and could scarcely believe his eyes. It went another 100 miles.

[David Cochrane]

is anyone supplying new rear hubs, Robert?

??? 
BO45 here.