September 10, 2012
One of the last remaining tasks for getting the Locost on its wheels involves refurbishing the front hubs. As we've mentioned before, and I think on more than one occasion, we have been putting off this task since last spring because we were pretty sure it would not be fun. And once again our automotive instincts were right on the money.
There's just no easy way to clean greasy, muddy car parts. Unless you have a solvent tank. Which of course we don't. What we have is a tin pan and a can of Brakleen. We also have a well-worn wire brush that has no visible effect on mud and grease, and a collection of dirty towels that more or less just spread the mud and grease around. Still, despite these obstacles, we managed to clean both front hubs and brake backing plates well enough to expose all the rust underneath.
We got most of the rust off with a wire wheel, but some of it looks like it might be permanent. We're actually okay with that. The hubs are big, heavy chunks of cast iron and a little rust isn't going to bother them. We were slightly more interested in getting all the rust off the backing plates, so we did what we could, and then painted them with Rustoleum primer for rusty metal. They're not critical parts, and if sometime down the road they completely disintegrate, we can get replacements from Moss for $30 apiece. Bargain.
With most of the rust gone, the hubs looked good enough for new wheel bearings, so we punched out the old races and pressed in new ones. We weren't 100% sure how to do this, but the old bearing races weren't in there very tight, and so it didn't take a lot of imagination to figure something out. Later on that evening we researched MGB hub assemblies online, and it turns out we didn't do anything wrong. So all that's left to do now is pack the bearings with grease and bolt the hubs to the stub axles.
Like the brake calipers, the hubs look pretty decent unpainted, especially when you consider how bad they'd look if we tried to do anything fancy with them. So I think we'll use them as they are, at least for now. In the meantime we bolted on brand new shiny brake rotors, which will no doubt improve braking performance, but more importantly make the hubs look almost new. So now it looks like our front suspension is ready to go, or will be as soon as the paint on the backing plates dries.
The rear suspension isn't quite as ready to go, but we've made some progress on it. We had to remove the old link bracket from the rear axle, the one with the misplaced Panhard rod, and tack weld on the new one. Then we had to fully weld both brackets. You may recall that we'd hoped by now to have discovered an alternative to welding this part ourselves, because our initial foray into melting the massive MGB rear axle tube was less than impressive. But we figured, what the heck. We made it this far, might as well give it a go.
Our main fears, besides the obvious one of making crappy welds, were 1) bending the axle tubes with excessive heat, and 2) welding the bearings to their races with excessive arcing. To ameliorate the first, we welded the axle in 8 stages, waiting half an hour between each stage for the axle to cool. To eliminate the second, we attached the ground strap to the axle housing inboard of the bracket, with the hopes that the billions of little electrons running around inside the casing would not find the wheel bearings.
The operation appears to have been a success. The axles turn freely, which means that the bearings aren't solid slags of fused steel, and the axles aren't binding inside a warped tube. During the actual welding we made sure to move the torch in wide circles so we'd melt both the axle and the bracket. We think the beads came out looking pretty good, and if you go by the old welder's rule of an inch per thousand pounds, our four 4" beads should be good for about 10 G's of acceleration. Beyond that of course the axle may fail, but we like our chances.
We're now down to our last nine tasks before we can roll the Locost out of the garage and into the sunlight. Yes, it'll be exciting, but it'll also be difficult to resist the urge to coast our new car down the street. We'll just have to keep reminding ourselves that while we do have a brake pedal, the brake lines are not yet installed, and the ultimate stopping power of the emergency brake is not fully tested. Or tested at all.
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