Today I finally finished removing the rear wheel bearings from both axles, a process that has been going on over a week. Before I began, I found a very useful write-up by Tom Walter (who happens to live in the same town as me, small world!) in the roadster mailing list archives.
Below is a picture of the axle assembly from my manual and one of the axle assembly before I began.
As shown below, the wheel bearings were held in place by a collar that has a ridge around its center. The bearings and collars are pressed into place. What I took from Tom’s post was that it may be preferable to cut off the collars rather than press them off, so that the wear on the axle is kept to a minimum and the new bearings and collars, once pressed on, will be less likely to come off. That is, pressing off the collars may wear-down the axle unduly and reduce the life of the axle, which is typically good for a finite number of pressings. Rather than using a Dremmel (mine is very wimpy and didn’t cut effectively at all), I used progressively larger drill bits to work away at the collar.
The 1/8″ bit I was using worked its way through the ridge in the collar.
Then I switched to a 3/16″ and then a 1/4″ bit, enlarging the hole in the collar each time.
The drill left a groove through the collar at least as deep as the ridge. I then inserted the tip of my cold chisel into this groove and started pounding with my 3-pound sledge hammer.
After around ten to fifteen solid blows with the cold chisel, the groove in the collar was getting deeper and the inner diameter of the collar began to expand. Eventually the collar came loose around the axle and slid off.
Here is a shot of the collar after it slid off the axle.
Next, in order to remove the wheel bearings, I held the backer plate in my hands, axle-end down, and slammed the axle downward into a block of wood on the floor. The idea was to use the force of the backer plate, which has maybe a half and inch of play up and down on the bearing, to knock the bearing off the axle.
On the left axle this worked nearly immediately. On the right side it did not. After my hands got sore from the impacts, I decided to soak the bearing in Liquid Wrench, which I did each night of the last week. Then I switched over to PB Blaster which, after several days of soaking, worked the stubborn right axle bearing free.
After the bearing slid off, there was a small spacer and then the backer plate, then the grease catcher that rests against the axle hub.
Next I went to work on the backer plates themselves. On the outside of the plates reside the brake cylinder and the adjustor, opposite. On the inside of the plates the cylinder and adjustor are fastened to the plates.
First I removed the cylinder, which was covered by a rubber dust cover.
The cylinder itself was held up against the inside of the backer plate by a series of clips. On the left side there were four of these clips, on the left axle side (shown) there were only three. I pushed the clips off using a flathead screwdriver, and the occasional tap of a mallet.
Off it came, and underneath were two more interlocking clips, that appeared to be copper.
I removed these to opposing clips in the same manner.
This allowed the cylinder assembly to fall back off the backer plate.
With the cylinder removed, I began to work on the brake adjustor, onto which the opposite ends of the shoes attach.
On the opposite side the adjustor was held in place by two nuts, which I removed using a 7/16″ socket.
The adjustor didn’t come off immediately, so I tapped the ends of the bolts lightly with a hammer, and it came free.
The adjustors appear to be frozen, but I will make an attempt to get them working again. If not, I will find replacement parts.
Next I took the backer plates outside and cleaned them up.
The backer plates are the last of a lot of parts I will send off to be sandblasted and powdercoated. When I get those parts back I should be ready to re-assemble the chassis.