"Aim High" is the Secret of Maintenance I N planning a
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scheme of maintenance for a fleet of vehicles it should be arranged so as to make sure not only that all the work that should be done is done, but, in cases of doubt, that rather more should be done than may, in the long run, be necessary.
As the outcome of close supervision of the vehicles, and a check from time to time as to the efficiency of their upkeep, it is likely that the original scheme will need revision, which will probably take the line of reducing the work so that the amount done is all that is really necessary for the object in view.
In August of 1938 I reviewed in considerable detail such a scheme of maintenance which was then used by Unilever, Ltd. It had been planned by Captain J. B. Walton, chief transport engineer to the company.
Exclusively a Mileage Basis ' This system has been further revised in the direction of diminishing the work which must be done on the vehicles, and in this article I am allowed to give details of the up-todate issue of this scheme of maintenance.
Examining the new plan and comparing it with the old one, extensive modifications in the overall scheme are at once evident. The first thing I note is that the present scheme is based on mileage only. In the previous one there were two sections. One related to vehicles covering small weekly mileages, and in this the operations were spaced on a time basis. In the other section all were on mileage.
Next, I note that there are fewer principal operations— four as against six—that the periods between them are considerably longer and the overall length of the cycle, from start to the major overhaul which terminates the series, is somewhat longer than in the previous case. The mileage which is allowed to be covered between one operation and the next is now 4,000, as compared with 2,500, and the total mileage cycle is 48,000 instead of 45,000.
In that period of 48,000 miles there are thus only 12 operations altogether (several of these are repeats), whereas previously in the 45,000 miles there were 18 operations. The foregoing is in addition to the daily and weekly valeting services, which are practically the same as before.
Details of each principal operation are set out herewith, as welt as of the daily and weekly valeting service. Operation 1 occurs when a vehicle has covered 4,000 miles and is repeated as Operation IA at 8,000 miles. Operation 2 comes at 12,000, and so on, as set out in the small table entitled "Scheme." It should be noted that Operations 1B, IC, ID, 1E, 1F and 1G are all precisely the same in detail as Operation I, just as Operation 2A is the same as Operation 2. There are thus only four principal operations. namely, Nos. I, 2, 3 and 4.
The difference in detail as between the old and the new seems to me to be of considerable importance, as presumably it shows how experience in the application of the older one has shown what modifications are necezary. Some, no doubt, are due to improvements in the design and construction of the vehicles concerned, which have made some of the operations unnecessary, but I should imagine that the majority of these differences has been brought about as the result of experience of the working of the original scheme.
I propose, at any rate, to devote myself now to a discussion of these differences, leaving the reader to examine the schedules of operations himself and see how far it is practicable for him to apply the same or similar methods.
Turning to the first schedule, that entitled Daily Service," it is found that this is the same as the previous one, except for one task, Previously there was an item "grease or lubricate any special points mentioned in the chassis of the particular type of vehicle being operated." The deletion of this item may possibly be due to the fact that modifications in the chassis have eliminated the special points. Alternatively, it may be that experience of use has shown that these points are not, after all, so special and the lubrication can proceed at the same pace as that which applies to the other lubricating points on the chassis.
Attention Week by Week There are one or two important modifications in the second schedule, the " Valeting Service." This is really a weekly service. The provision laid down, that it should be carried out every 7-10 days, is, presumably, to allow a tittle latitude in case it may not be practical to have the vehicle in for service at precisely seven-day intervals.
The first thing to note is the modification to item I. The words "renewing grease nipples where necessary" are new, which seems to indicate that trouble has been encountered owing to the fact that the grease nipples became inoperative and that immediate replacement is the best course to follow.
In the previous schedule a recommendation ran "Check up condition of batteries, electrolyte level, terminals, etc." All that there is of that in the new one is "Top-up batteries." It has evidently been found unnecessary to make the check described as frequently as once per week.
As regards item 2 in this weekly service, it is of interest to note that, in the previous edition, cleaning and spraying springs was called for only every fourth week. No. 3, "Check gearbox and back-axle oil levels," is a new one for this weekly schedule. I should imagine that item No.. 5 is merely a reminder that tyre pressures should be checked daily e,nd, if necessary, at week-ends.
In the previous schedule it was regarded as necessary to check the chassis over every week for any loose bolts on wings, body, steering. mudguard brackets, etc. Apparently it is now seen that there is not the necessity to carry out this operation ao often as once per week. Item 7 is now used significantly. . . .
Turning now to Operation 1, the first thing to note is that this is called for only at 4,000 miles. It appears to have taken the place of Operations 51 and 52 in the previous schedule, which were to take place at 2,500 and 5.000 miles respectively.
Checking up the items, 1 sec that in item 3 the words "if necessary" are new, as also is Item 7, "Sparingly lubricate auto. advance and dynamo bearing." There was an item in the old schedule "Top-up gearbox and back axle with oil." That, as has already been mentioned, now appears in the weekly Valeting service, it having apparently been found unsafe to leave the level of the lubricant in' those two components unchecked for so long as 4,000 miles.
Life of Brake Facings Longer
An improvement in the wear of brake facings seems to be indicated by the fact that item No. 10 in the new schedule, "Test brakes and adjust it necessary," replaces one which called for an examination of brake facings. Item 11 is the same as previously, except for the addition of the words "and lift in front hub bearings."
• Turning in, to Operation 2, which is scheduled to take plaCe when the vehicle has covered 12,000 miles, this appears to replace two operations in the old schedule. namely, No.' 53, due at 7,500 miles, and 54, due at 15,000 miles.
Items 1, 3, 4, 5, 6, 8, 9 and 11 were all included in Operation 53 in the previous plan, and therefore deemed at that time to be necessary at 7,500 miles. There is a eon siderable jump from 7,500 to 12,000 and a corresponding economy in maintenance costs,
item' 2 in this Operation 2, "Renew sparking plugs," appeared only .in Operation 54 previously, and that took place at 15,000 -miles. That may mean that sparking plugs have been found not to last 15,000 miles. On the other hand,. it May mean that, to conform with the plan, if the plugs be not renewed now they, will have to go another 12,000 miles, before which they would be giving trouble.
A part of item 13 is new, as compared with the previous schedule 54 (15,000 miles) as there was nothing in the previous schedule calling for "touch up and varnish exterior and re-distemper interior." It is presumably an economy in the maintenance of bodywork to carry out renovations "little and often."
Overhaul at 24,000 Miles I come now to Operation 3, which must take place when the vehicle has run 24,000 miles. This is largely a repetition of Operation 2, as it. should be, of course, as the initial period of 12,000 miles has now been repeated. The additional items are 4, "Renew water-hose connections and wash out radiator and water jacket "; 5, "Examine transmission, universal couplings, Spicer couplings, and adjust clutch-pedal travel if necessary."
In 7, 8 and 9 there is clearly provision for an extensive and thorough overhaul of the brake gear from end to end.
No. 10 provides for a more extensive. examination and check of the electrical system. It is interesting to note that it is deemed desirable to renew the lamp. bulbs throughout,
at tint mileage. Item 12 is also additional to anything in Operation 2.
No comment is needed on Operation 4 beyond the fact already stated, that it comes at the end of 48,000 miles, whereas in the previous schedule the limit was 45,000 miles. It is a matter of interest that this company is able to rely upon the engines of its vehicles to give efficient service up to 48,000-miles before reconditioning becomes necessary.
There is an item in Operations 2, 3 and 4 which did not appear at all in the previous schedule, and that is No, 12 in Operation 2, and No. 17 in Operation 3. "Lubricate cab door locks and hinges, and adjust if necessary. Lubricate bonnet hinges and fasteners." S.T.R.