Half Shaft replacement 1928 Chummy

[datcoor]

Hi,
Very grateful for any info on replacing LH half shaft on 1928 Chummy. Looked at most places on I'net but cannot find procedure and I d wish to get it right. Thanks, Dave

[Bob Culver]

This must be covered somewhere and soemeone will find a ref.
Bear in mid that the original meshing (or better) needs to be preserved. The assembled gasket thickness influences this, and the bearing preload. Comparison of the old and new side gaskets will give some clue as to any adjustements necessary. Noting the exact backlash may prove useful later.
Care is necessary not to accidentally heavily preload the expensive bearings, and ruin by forcing dents into them.
The fitting of the replacement axle to the hub has been extensively covered largely under the topic of lapping.

[Howard Wright]

Hi Dave

You can’t go far wrong by following The Austin Seven Manual by Woodrow.  If you don’t have a copy I thoroughly recommend you get one!

Cheers

Howard

[Robert Leigh]

Dave
If you are unfamiliar with the technique and possibly the internal layout of the axle components there are some useful things to remember. If you know them please don't be offended by my assuming your ignorance. You need to remove the left side of the axle casing, which can be done by removing the spring pin, after you have removed the brake drum and hub. You wil need to disconnect the brake cable. Remove the halfshaft nut from the offside and split the halfshaft taper by means of a hub puller. Undo the bolts on the left side of the differential, and the left axle case can then be removed, followed by the differential complete with halfshafts. The differential has to be dismantled to remove the left halfshaft. Re-assembly is basically the reverse of dismantling. Clearance between the crown wheel and pinion should be much the same as it was before dismantling, because you have done nothing to change this, except probably fit a new gasket. When the whole axle is in place on the car you need to tighten the half shaft nuts properly, especially the offside one. Try to protect the puller threads on the hubs: if you damage them with your big spanner you have difficulty fitting a puller next time. That is the basics, but do read anything else you can find to get it completely right. If you have someone more experienced locally there is nothing like having him/her present when you first tackle the job. Good luck!

[Stuart Giles]

Easiest way is as Robert's post above.

You might need to shove a piece of bar or such through the left hand spring eye and lean down on the spring to get enough clearance to withdraw the axle tube.

When splitting the diff to remove the dud halfshaft, put one halfshaft in the vice, slide either of the halfshafts into the diff and it will lock making it easier to undo the nuts that hold the two halves together. If there isn't any marking from a previous stripdown, scribe a line across the two halves of the diff to make sure you put it back together with the same orientation.

Before assembling your hub onto the replacement halfshaft it's well worth lapping the two tapers together with some coarse grinding paste to prevent the hub and shaft seating on a couple of high spots which will cause the hub to shoot loose later.

[Robert Leigh]

Stuart's comments are useful. I would add that lapping hubs onto shafts is not without pitfalls: when either component has been lapped repeatedly you can reach a situation where the pinion on the inner end pulls hard against the inside of the differential, adding swarf to the lubricant. If you are going to lap this taper be very sure that both components have enough material on them to allow for the reduction. Personally I rely on both components having a good taper, and never do more than clean off any high spots with a small fine file; then I do up the hub nut properly. This needs doing repeatedly after each of the next short journeys until the nut does not pull up any further. I do not do the lapping process, and after proper tightening the hubs do not work loose. When tightening hub nuts I place a very short piece of 35mm stainless tube over the hub thread, after splitting it to allow this. Its length should fully cover the thread to avoid damage from whatever large spanner you may use to tighten the nut. Personally I have a large ring spanner and tighten enough pulling upwards to lift the relevant corner of the car.

[datcoor]

Thank you all for your very relevant and helpful replies. I am not offended at all by your comments Robert, everyone can learn something and the best way is to assume ignorance !
I emigrated to Australia in 1971 and brought the Chummy with me. It performed very valuable service when my other car was being repaired. However, the Chummy showed its displeasure when the other car came back into service by breaking a halfshaft outside our garage so it did show some compassion. Thank you all again for your time and help.

[Tony Press]

I would remove the rear axle complete to strip it down on the bench.

I am sure a Queensland Club member could offer advice on the job,

[datcoor]

Thanks Tony, good idea and I should have thought of it and of contacting a QLD club