Rear wheel bearings
Well I can't leave anything alone can I - checking over my car prior to MOT testing, I thought there was a little play in the back wheels. The bearings are ballraces and not adjustable, I had seen them when getting at the brakes. I decided to replace the bearings, starting with the nearside which I had not seen yet and seemed to have the most free play. I had to remove a bearing, measure it and put it back as the bearing factor is 15 miles away and I hadn't time to cycle into town.
Anyway, getting the drum off involves removing the wheel, then the centre stud, as per brake access. The drum proved MOST reluctant to come off, the usual slack handbrake and rubber mallet barely moved it - drat! I had to make a puller, see below:
The lump of 1/4inch steel was under the bench, an old welding practice piece. A hex screw about 6mm thread went in the centre hole, nut in the back, and the wheelnuts held it in place. Of course it had to press against something, a short bolt from the toolbox bottom:
Now why wouldn't it come out earlier? Answer, someone had been doing maintenance "wiv a big 'ammer" at some time. The outer bearing was sticking on this gall in the stub axle, I had to clean it up before the inner bearing would come off!
The above photo shows it AFTER treatment with a fine file and abrasive paper. Well at least it got out the back bearing for me :o\
Getting bearings out of an alloy hub is easy. Use a heat spanner. If you don't want the roast dinner flavoured with lithium grease, then avoid the kitchen oven, and use a hot air gun. With the drum heated to the point where spit will sizzle, the bearings should either drop out or come out with the lightest of persuasion from a hammer and drift. Remember banging away at the inner part of the bearing isn't good for it if the outer is the tight fitted part, it bangs the balls into the track - go easy if you want to use the ballraces again. Oh yeah, and DON'T pick up any of the parts barehanded like I do. Well once is Ok. Just to check they are too hot to hold.
Not only were the old bearings somewhat dry (they rattled easily) but the rubber seals were in a sorry state, oddly enough just the inner seals - weird:
You can also see that the bearing numbers were illegible :o( this was the clearest one. Anyway, I measured them at 25 x 47 x 12mm, and got some more (10 pounds each) from a local bearing factor. They are nice shiny NSK 6005DDU sealed ballraces.
Before fitting them, I had a thought as to why the inner seals looked so bad. Could it be the bearing spacer, which is the only thing touching the inner face? The thrust face of this spacer is somewhat wider than the inner race, and could be dragging on it. Well, wouldn't hurt to alter them a bit. Here is the spacer as it was, and after a few minutes hand filing the outer bevel a bit bigger:
I hope this is enough. If I ever take them out again, I'll let you know!
Refitting the bearings means warming the drum back up, they should go in easily if straight. Support the first bearing on something when you turn the drum over or it may fall out again as you put in the spacer and second bearing.
I was a little alarmed at how easily the first inner bearing came out when cold, so used some bearing fit Loctite on the outer metal. There were some score marks on the alloy of this hub, more past scars from the mechanic wiv der big 'ammer I think.
The offside drum came off with no trouble and bearing swap was a repeat of the above. Both wheels show a "just feelable" play and the nearside is definitely less than it was.
One last thing - I replaced the axle nuts with new Nyloc nuts from a bolt and nut specialist. Oddly enough I need a 19mm socket for the new nut instead of 18mm.
Back