Dismantling the rear uprights

This is a job I have been dreading, because, having read up on it, I know (i) it's all too easy to cause a lot of damage with too much enthusiasm (ii) I know just about everything needs unseizing and half the studs and bolts have already been broken off in the ally casting. So it might turn out to be a bit of a bugger.

I've been looking at these uprights every time I got into the shed, for months. So, today I finally bit the bullet, got out my 1 1/4" socket and stripped down the first upright. Everything has been comprehensively soaked in WD40 so it all pretty much came undone without fuss. It had already been stripped to the backplate, so the brake mechanism was not in place. The catellated nut on the rear flange came off with ease; the quill shaft is supposed to come out fairly easily after this, but it did need a bit of a firm tap. The back plate itself came off pretty easily. It may have been off before because it was held in place by a mix of nuts and studs.

The casting cleaned up relatively well with a wire brush, but you can see where one cotter pin and a couple of the studs are sheared off. Its also sufferd a little from electrolytic corrosion between the backplate and the flange, which had expanded and, quite amazingly, bent the backplate out of shape! There had also been some electrolytic damage between the handbrake bracket and its mounting by the look of it.

The flange looks a little rough, but once the broken off studs have come out, I am going to get the whole casting checked over. The rod also looks bent, but I was planning on replacing that anyway.

This is the second upright. It also looks pretty poor.

The bolts that hold the handbrake bracket have also sheared off on this oneand the rod holdng the shocks wishbones and track adjusting arm has been cut, but as for the other upright, I plan on replacing it anyway. One of the cotter pins also seems to have sheared off.

The brakes were siezed fast onto the drum, so I thought I would first try slackening off the adjuster to allow them to loosen up.  No such luck of course, the adjuster had virtually fossilised after 24 years gently corroding, and it just sheared off.

In order to get some purchase on the drum, I undid the nuts holding the adjuster to the back plate and tapped the adjuster into the drum. Then I removed the clips holding the slave cylender and pushed the slave cylender free. This gave a little free play on the drum but not enough to free it off, so finally I undid the castellated nut, pulled off the flange, replaced the nut to protect the thread and tapped the quill shaft. This finally freed the brake shoes and popped off the drum, but now I need a new castellated nut!.

Here are all the bits:

Broken adjuster bottom right.

The quill shaft was still held in place, but it comes out with a firm tap and here it is complete with the front bearing, oil seal and crush tube, whcih you can just about make out on the left side of the shaft, covered in grease.

The bearings will be replaced of course and, obviuosly, the shoes, pins and clips will also need to be replaced. Fortunately, to my great surprise, the slave cylender was fine once it was cleaned up and will need only a recon kit. Unfortunately there appears to be some play between the quill shaft and the flange on this upright so they will probably have to be replaced too. Not sure about the studs; someone has sawn them down .....

Despite the brake pads being siezed onto the drum, the drum itself looks to be in reasonable condition. It just needs an internal clean and visit to the shot blasters to clean up the outside. The other drum will need the same attention.

The casting of this upright looks fine. There is no electrolytic damage between the backplate and the casting, although there are a couple of sheared off studs.

Thanks to the authors of this http://www.zen11896.zen.co.uk/vixen/parts/vixen_rwb.html for the expanation of how to dismantle the hubs.