“ SUN ” SERVICE STATION

Sun (Auckland), Volume III, Issue 830, 26 November 1929, Page 6

“ SUN ” SERVICE STATION

THE '‘Motordom’' section of The Sun includes 111 Its service to readers a Queries and Answers Department, the object of which is to give accurate information regarding mechanical and touring subjects. Whatever the particular puzzle may be in either diagnosing irritating troubles or motoring information of any kind, “Headlight* will endeavour to help, or refer the point to men who are recognised automobile experts in their respective lines. All communications must be accompanied oy the inquirer's name and address (not for publication;, and sent to TH ti SUN “Service Station , Motordom.” THE SUN, Auckland. Answers will appear weekly in this column. •*.

C.T. —Can you tell me anything about the use of white chalk inside covers, because, personally, I don’t think it does any good?

The use of French chalk between the tube and outer cover is practically essential to prevent adhesion of the tube to the cover. However, too much is likely to ruin the tube. The chalk works itself up into little balls and the continual rolling and rubbing will chafe the tube till a blow-out results in one or more places, making it hardly worth repairing. If water gets under the cover it helps the destructive work.

N.M.P. —I have been having a lot of trouble with the clutch of my car (light American six) lately. First of all, the clutch plates slipped badly, so I had them renewed, but now find that the top gear will not stay in mesh.

I do not think that the fitting of a new clutch plate would in any way bring about the slipping out of gears, this trouble in all probability being confined to the gearbox. I would suggest inspecting the gear selector spring and adjusting with a slightly heavier replacement. Further, there may be excessive end-play in the gearbox shaft, which would also tend to make the top gear slip out of mesh. Apparently the tendency to disengage did not develop until after the clutch was attended to, which might possibly he explained by the fact that the original clutch (which was evidently in- a bad condition) wcu’d possibly allow a certain amount of slip, especially when travelling slowly, a condition which war; eliminated when the new clutch plate was installed.

J.c. —l have a 1927 Chrysler 60, and it burns an enormous amount of oil. It just had new rings in, but I have gone over 1,000 miles since and am using Mobil A. Do you suggest a heavier grade; does it >vant a set of new pistons, or what is your own opinion?

Probably the car has done a fair mileage, and the cylinders are worn, therefore, new round rings, fitted into oval, tapered cylinders would fit the walls only where they touch, and would not give results as good as the old cylinders which had worn themselves into shape.

“Owner.” —What is the maximum amperage advisable for a 12 volt Lucas battery?—When on full charge on the 1929 Morris as much as 14 amps are registered; while half charge shows only abqjut 6 amps., less when the system warms up a little. The high rate is very handy at night, when the lights are on, and the low rate seems hardly enough for day running, and if necessary I would have some adjustment made; but there seems to be conflicting opinions on the matter of a high charge.

1 our maximum charge should not exceed 10 amps, when the generator is warm: until it warms, the rate ,will be slightly higher. On this setting the low charge rate will be about 4 amps, with a warm generator, and this is sufficient. These are the recommendations of the manufacturers. Have the third brush adjusted to make the charging rate agree with these recommendations.