Replacng rear axle assembly

[Dennis Nicholas]

Also found....the inner faces of the lugs on the axle casing, that the spring pins go through, not parallel due to wear (just like the inner thrust faces on the stub axles). I spent quite a while filing up wedge shaped washers/shims to fit and take up side wear between spring eye and lugs. (oh to have a surface grinder with adjustable bed or vice)

Dennis

[SneezerUSA]

The good advice keeps coming.  Thanks

[Hedd_Jones]

To remove an axle, the worst job is getting the spring pin cotter pin out. So you can then remove the spring pin, which can also be a chore, if its been there a long time and your hubs are still on.

If you plan fitting new springs (as I am about to do shortly on one of my cars), I find the easiest way is to lop the bottom leaf of the spring with an angle grinder. You can then deal with the cotter, and the spring pin on the bench, rather than on your back under the car. Clearly don't do this if you want to keep the springs.

When I do this job, I make sure the springs are loose in the chassis for when I put the axle in.

By that I mean I have the springs in, and the vertical bolt in, but its loose and the U bolts also loose.

Rarely are the springs an interference fit in the chassis (unless they' ve not been out in 50 years!), so with a little clearance, you get a good bit of waggle at the axle end of the spring, which in turn helps you get the pins in.

A large shifter (shifter = Adjustable spanner) is also very useful, as sometimes you need to twist the bottom leaf a smidge to get the spring pin in. The other solution to this problem is to grind a lead on it and fit it with a course persuader.

Personally I don't worry too much about wear on the the eyes on the axle so long as they are strong enough to do the job. The geometry of the rear suspension on an Austin 7 is a total mess. As the springs flatten, the axle end of the spring goes backwards and out (in plan looking from above).

If you assumed the springs fitted perfectly in the axle eyes, and the pin the same with no clearance, and that the spring was solid in the chassis, assuming the chassis itself is rigid. So when the axle moves relative to the chassis the spring wants to do all sorts of things that the chassis and spring pin and axle ears try to stop it. My view is even if you had it all perfect on assembly, within a couple of hundred miles it will have worn itself the necessary clearance needed to operate how it does in the real world. For this reason the torque tube is basically a ball on a link. The axle rotates around the ball, which is in itself not a fixed point because of the link.

As I said, total mess.

[Howard Wright]

Hi

Here is another tip.

Once you’ve got the spring pins in you will need to move them in and out and around to align the cotter pin. Use two nuts on the damper thread at end of the pin tightened together. You can then twist with a spanner to alight the cotter in the hole.

Cheers

Howard

[SneezerUSA]

Another problem has popped up. I am trying to remove the ball from the extension on the torque tube pivot. No go. Is the cylinder inside the extension supposed to pop out?  Photo attached.

[Tony Press]

Yes- - sometimes tight but you should be able to lever it out.

[SneezerUSA]

I'll try harder.  Thanks for the reply.    Arnie

[Bob Culver]

Agree with Hedd it does all seems somewhat complex. Maybe patents were involved but many cars had full torque tubes as the Model T. These do not produce hopping and with no spring wind up are superior to Hotchkiss drive in heavy going.

[SneezerUSA]

New problem has cropped up. My torque tube universal joints are obviously different. I am thinking the existing joint will have to replace the joint on my replacement rearend. Is this possible or what should I be doing?  Sorry to keep bothering everyone.  Regards:  Arnie

[Bob Culver]

Dunno what model you have but there was a change from a pot type universal as top photo to a more conventional universal as below (except it has plain bushes not needle rollers) around 1933. The drive shafts differ. Dunno if  flange on the diff the same; others will advise. Looks different. It and the universal can be changed but some care is necessary.
The later universal should have barely detectable lost motion in the innards. Long lived when well greased but many not.....I am curious that the ball joint is not adjusted up. This, and many other checks are conveniently explored before assembly.
I am not sure which is the replacement.
What has prompted the diff change?
Are original grease nipples collectable?