Jack repair

Servicing the brakes today I used the suicide jack to get the wheels off. Lifting was more difficult than it should have been. Stiff, and a half-a-turn backlash in the handle.
So it was time to have a look at it. I drilled out the 5 rivets holding the top on the gearbox. Inside there is a worm and pinion which drives the screw thread. The pinion was very worn one one edge only, and if left too much longer would have failed completely.

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The reason for this was that the thrust bearing at the bottom of the screw thread had collapsed, so the whole thing was several mm too low. I can imagine the gearbox failing with the van partialy lifted on the hard shoulder in the dark and rain somewhere, and not being able to get the van up or down. Embarrassing and dangerous!

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Fortunately the pinion can be pulled off and turned over, to use the unworn side of the teeth, and new bearings are available cheaply. The bearing is 51200 (or thrust bearing 10x26x11mm). It's 1.5mm thinner than the old bearing, so will need a washer.

So this is a "heads up" for everyone still using the original equipment jack. Check it still has a complete thrust bearing at the bottom. If not, best get it sorted before it lets you down.
 
Following on from some other discussions about the wooden Jack handle knobs either being missing altogether or coming off easily, I set about sorting that too.

The problem is that the turned wooden knobs are held on by a little pressed metal "top hat" clip which grinds away at the handle. I looked for replacement clips but it's a hopeless task, and they don't work anyway.

Original knob and clip.................DSCN1137.JPG

Here's my solution..............

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It consists of a spacer (which won't go round the bend of the handle), a washer, a turned knob with a recess in each side, and a capped starlock washer.

When fitted it looks like this............

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............and it doesn't come off every time I wind the handle!:)
 
I was in the same situation a couple of days ago jacking Bonnie up to check the brakes. The jack was very stiff and making strange noises o_O
So off with its scull cap

Seems OK in there

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I was trying to figure out where the bearing went and spotted this

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Not a ball in sight

From where it came

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New one fitted

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And the top re-attached with some M4 set screws and nuts

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At £2 a pop I got a few with the intention of doing Harvey's jack but when I checked it was fine and still intact so still got a couple spare.
I still need to make a couple of handles to finish off and will follow Colin's method for that.


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