Joined: Aug 2017 Posts: 1,532 Threads: 90
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Location: Monmouthshire
Seeing a certain amount of use for essential shopping, the Ruby has put in many miles, generally in a smooth and delightful manner. I have occasionally caught the sound of slight hesitation, never in a particular way or dependent on speed or throttle. Today, having earned a bucket load of brownie points on some domestic decoration, I went to the workshop and opened the bonnet. I checked wiring, plugs etc and found nothing wrong. Then for some reason I tried the distributor and discovered some play. None of the fastenings were loose, but there is distinct movement of the body of the dizzy. The distributor is quite recent from Willie MacKenzie, the dynamo was rewound a couple of years ago but I don't recall further work such as new bearings. This is to ask if there is anything I should look out for, or any particular steps to take? Otherwise is it just take out distributor, and then what might I find?
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Steve,
Is there movement between the body and its mounting or between the body and the internal vertical shaft?
Peter.
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Location: Darkest Bedfordshire
The distributor should be a fairly snug fit in the dynamo housing and secured by a 1/4" bolt down through the plate at the base, which additionally clamps the body via a pinch bolt, also with a 1/4" bolt sideways into the dynamo casing which locates in a groove in the distributor casing and prevents it pulling out vertically. Step one I suggest is to check all three are tight, unless as Peter suggests, you are talking about internals.
In that case is the rotor arm loose on the shaft? (They often are, but should be quite tight). Otherwise most likely the distributor bushes are worn. It wouldn't do any harm to lift the distributor out & check the drive gear teeth are in good order, there have been a number of failures on new parts from certain suppliers.
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Location: Scotchland
How much movement do you have in the dynamo armature?
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Location: Monmouthshire
Now, how do I check that? Take the dynamo off and see how firm, or wobbly the armature is?
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Location: Sheffield South Yorks
Car type: 1932 RN saloon
17-06-2020, 04:14 PM
(This post was last modified: 17-06-2020, 04:19 PM by Dave Wortley.)
Surely you can check for axial play by removing brush cover and seeing if it will move or as you have removed dizzy poking something down the hole in dynamo housing and checking movement. Up and down(radial) movement try lifting rotor with fingers through brush cover or bent wire under skew gear if possible. The oilite bush at brush end of rotor wears fairly rapidly.
The bearing housing at the engine end of some coil engined cars has a bearing retainer which is attached to the housing with 3 countersunk screws which come loose, allowing the rotor to float. If so loctite the screws in.
Cheers,
Dave.
Joined: Aug 2017 Posts: 1,532 Threads: 90
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Location: Monmouthshire
Dynamo removed and the spring located end cover removed. The engine, inside end, is tight, but the end driving the coil has slight but noticeable play. Now might this be the oilite bush, and if so what's next to do?
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Hi Steve, i would suggest that the depth mesh position of the distributor needs checking. The gear needs to be in the correct vertical position relative to the centre line of the gear on the dynamo armature. This is controlled by the 'length' from the centre of the teeth to the underside of the clamp that mounts the distributor to the top of the dynamo. This clamp position is in turn controlled by the shoulder on the distributor body that is formed by the end of the machining of the distributor body outer diameter. This distance needs checking against a standard Lucas distributor. I have not used bosch unit for this (and many other) reason for a very long time so don't have a clear memory if they are interchangable. I have, however recently set up an aftermarket distributor made for a VW type 1 installation, and this distance would have needed significant correction, had i simply installed the A7 gear using the cross pin hole for the VW drive coupling......My dynamo housing may be non-standard though.....W
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Location: Cheshire
Car type: Race Ulster, 1926 Special, 1927 Chummy, 1930 Box
The Bosch 009 distributor unmodified puts the gear about (from memory) 100 thou ish too high. You have to machine the “spout” of the distributor to make it longer. There is just enough metal in the casting usually. Alternatively, sometimes you can get special made for Bosch distributor gears.
Alan Fairless
