by Enright » Fri 17.01.2014, 15:23
Make a little score line or Tipp-ex mark to, er, mark the position of the CAS assembly before removing it.
Once off, they're quite easy to disassemble - in the picture, the thin ring (top centre and to the left of the 4 screws) is actually a spring, which can be prised off with a blade, a screwdriver (if you're careful) or even a thumbnail.
The spring simply retains the little dowel/peg, which goes through the hole at the end of the main shaft and the part with the offset dogs that meshes with the end of the camshaft. After the dowel is pushed out, the whole lot just comes to pieces.
It's the little dowel/peg that I've seen break into 3 pieces in the past, and it completely mucks up your base timing, but it can be easily replaced with a sawn-off drill bit.
The thing to do is to test for any rotational movement between the big wheel and the bit with the dogs on at the opposite end of the shaft. The whole thing should rotate freely (or with just a tiny bit of magnetic resistance), but the ends shouldn't move in relation to one another.
The bearing (centre right) can be removed by putting the whole assembly in the freezer for a few hours, then putting it face down and pouring boiling water on the aluminium. The ali of the housing expands quicker than the steel of the bearing and then if you tap it on the bench a couple of times the bearing should just fall out.
If it doesn't come out cleanly immediately, simply re-freeze and repeat.
You'll either find a bearing number on it which can be matched up, or any decent bearing supplier should be able to supply a similar off the shelf item for a couple of quid.
Remember to freeze the new bearing before trying to drift it into the new housing with a suitably sized socket resting against the outer race, and don't let it go off-square or it'll lock solid and damage the mating surface of the housing.
Striking fear into the hearts of duplicate posts everywhere...!
BCingU,
Neil
