Rear axle again.

September 2nd, 2013

Right, no updates for a while and slow progress but progress is being made. I rolled the car out side the other weekend to take some pictures and to be able to stand right back to see the shape. It’s looking OK I think. Tiny but OK!

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20130818_100631 20130818_100641 Car out in the sun.

I also took a couple of black and white film shots and some pinholes.

2013-08-19_4 2013-08-19_3 Film.

2013-08-19_11 2013-08-19_15 Pinhole shots.

I would have though the oxy torch would show up brightly on film but apparently not!

Work on the skin continues slowly. I also went to visit the spares and picked up a crown wheel and pinion then last weekend Joss and I took all our parts up to visit Ian who is putting together the mechanical bits of the car Joss is making. We sorted out all the bits and should be able to all get a working axle from them. Ian has many fascinating things there so most of the day was spent just looking at stuff. Very enjoyable. A happy time was had by all!

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I also finally worked out why I was having no luck with my rear axle. It seems that the torque tube bearings were causing issues. Now this is complicated but in most torque tubes Austin used a special narrow bearing for the two intermediate thrust bearings. These two fit back to back inside the torque tube in a housing that gets inserted into the diff housing. It is explained well here: http://www.austin7club.org/How%20To%2015.htm

I have the narrow bearings but my housing is actually machined to fit the later, full width ones. This meant there was a gap in the housing when the bearings were inserted allowed my pinion to move back and forth about 1/16 of an inch. The bearings are thrust bearings and must go in the correct way around with respect to each other – thrust faces together. If you fit them the wrong way around the outer races will have a gap between them when the bearings are together. The correct way there should be no gap.

IMG_4120_1 IMG_4121_1 Correct orientation.

Narrow bearings in the deeper housing will have the gap. I don’t know if the housing is original (for later bearings?) of it it was machined sometime in the past.

IMG_4124_1 Gap between bearings and housing.

The solution to this was to make two shims, I used 0.8mm panel steel, to sit either side of the bearings to correctly space them. The other alternative was to fit new, full size ones. On Ian’s advice I popped apart the ones I have and just fitted new balls to them.

IMG_4129_1 Bearings with new balls to be fitted.

I carefully cleaned everything and polished the inside of the races and the pinion shaft so the bearings were a good push fit on the shaft. It took a number of assembly/dis-assemblies so I was glad I did this and the bearings could be removed relatively easily.

I then found I had to add another shim washer under the spacer on the pinion to get the meshing in the ball park (so had to dis-assemble everything again) but now things should be fine to get the final adjustments done. I only have one shim under the housing but found after blueing I needed a little more (using temporary cardboard ones) so I am waiting to get another steel one then I think the adjustment is right. I can then finally assemble the rear axle.

IMG_4140_1 Waiting to be assembled.

Tonight I came home and did some more hammering on the body. That is definitely getting better and better and easier as I get more practice.

IMG_4142_1 IMG_4139_1 Body.

Finally, this week I also ordered from the UK a new Phoenix 1-1/2 inch splash crank and matching rods. With shipping to NZ it all came to 1330 UK pounds. I also expect to pay another 15% GST once it arrives in NZ. I need to look the the block I have and see if it’s useable. If so I can work out the bore size and order suitable pistons, again from the UK. The crank and rods should take 8 weeks or so to arrive.

2 Responses to “Rear axle again.”

  1. Nigel Hamlin Wright Says:

    Nice work Simon. I wonder if, like mine, moving the front axle forward 6″ would help to put the radiator over the middle of the front wheel for a more vintage look? It certainly smooths out the ride. I’ve got the plates if you want to have a go. I see that you’ll never have to worry about a flat battery – just push out of the garage, leap in and trundle off down the hill (you’ll have to be quick if you want to turn right and go up the hill!). Final thing: http://www.jp.com.au/JPPistons.html aren’t they a bit closer to you? They supplied my pistons (through an agent in the UK).

  2. admin Says:

    Am keeping the running gear completely standard for now (well, mostly) since that makes it easier to register the car. Standard late Austin running gear isn’t too bad.

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