| Show fi i A Little Care Will Stop l i II Useless Noises in the Auto AutoL L I Noisy operation is the bete noir nolI of the careful motor car owner Absolute Absolute Absolute lute silence is impossible to be attained in any piece of machinery esp especially in a vehicle traversing the roads under under under un un- der Its own power However it is pos- pos freedom to achieve a reasonable from flom loud noise by hy a little intelligent understanding and care The engine is thes eat of oC the greater that part of the really offensive noises sometimes beset the modern automobile automobile automo automo- bile The commonest noises arising arising from the engine are valve clicks and slaps These may be distinguished by the regular of ot their recur rence The cause may be to too great greata t ta a clearance between the valve stem and the tappet or in the case of overhead overhead overhead over over- head valves the clearance Between the lifter and the push r rod may be to blame The remedy for this tills condition Is the reduction of the clearance and this adJustment adJustment adjustment ad ad- should be made while the en engine engine en- en gine is hot This is necessary necessary because of the expansion of metal when s heated In which condition the valves valve operate grate If adjustments were made when the metal was cold they would not b be correct correct cor cor- after the parts had become h heated ed edwith with running Occasionally however clicking in the valve vahe mechanism is caused by a lifter being loose in its guide To Po 0 lo locate locale this tro l trouble the lifter assem assembly ly dy will j i have to be he removed and in the main a ai i worn lifter must be replaced Certain I designs of guides are such that the I guide may be sprung slightly so that it will grip rip the lifter tighter remedying I the tha trouble II I- I I CAM NEEDS SCRUTINY I Another location for trouble of this kind is at the cam between which and I it its follower there may be he too much clearance Fitting new followers usually usual usual- ly has a beneficial effect here Worn valve stems or br guides will produce noise Removal of the springs will en enable enable enable en- en able conditions at this point to be de de- de Thero There should be no play of the stem sideways in its guide and if it investigation discloses play a bushing should be fitted to the guide or else a valve with an oversize stem must be installed The Tho valve mechanism In an overheated overheated over over- I heated valve system normally develops more noise than does an ordinary L-head L engines engine's valves Systematic and adequate lubrication will do much to minimize noise here Occasionally side play develops in the rocker arms with a slap as the result A worn arm bearing will make trouble which may maybe maybe maybe be cured by fitting an oversize bushing in the rocker arm I While the time valves are arc the commonest locations of undue noise they are no not t are at all the sole ole seats of trouble i in the thc engine The bearings bearing in most engines are made of or soft metal metai which must be kept copiously lubricated or it burns becomes comes flattened and a knock results The ordinary remedy for this trouble is to take up the play by removing removing- the shim between the two halves of the part or else by uy trimming the metal on I the movable part Care Carp must be taken in performing this operation to see that the bearing touches the shaft all aU allaround allaround around without being too light IBE I BE CAREFUL I In fitting bearings the utmost care I I must be taken to avoid throwing the i shaft out of alignment and this condition condition condi condl- I tion is particularly likely to occur when I Iono I i ono one bearing is fitted i ted without reference I to lo the others In Tn unit power plant construction construction con con- conI I I if the shaft is thrown out ot or I alignment one of oC the gears in the i I transmission Is sure to bind with the result that noisy gear operation en enI en- en I I sues I Another other source of bearing knock Is 15 I the flanges of the crankshaft bearings I which are aro flattened by crankshaft i I thrust In this case It does not pa pay I I j to try to fix the old bearing flanges It is better to get a new bearing I Play frequently develops In the the- upper upper upper up up- per rod bearing and every often the motorcar owner blames the lower rod I or crankshaft bearing for the trou trou- ble On many of the cheaper carsI cars I there is no bushing at the tho top of the therod therod rod while In some others a bronze j I busing will be installed to take tale up the wear When there is no bushing a aI anew I new piston pin will have to be fitted or orI orIf orif I If the piston bosses are worn eccentric I it may mean a new piston or the tho in- in installation In Installation installation of a bush bushing InS InS' I When the piston or cylinder Is worn it results in a a. knock that is much like the sound that comes omes from pre- pre ignition If this trouble is not severe 1 I i lit It may be cured b by fitting filling new piston pis piston pis- pis I ton rings On the other hand band a a. severe pre I case may call for the installation of ofa ofa I Ia a complete new set of pistons When the cylinder block has worn in a slightly slight slight- ly oval shape it may be and fitted with oversize pistons which maJ makes s it practically a new block TIMING GEAR Timing gear or r chain noises are dIfficult difficult difficult dif dIf- to cure In certain makes of ot ellent ellent el- el lent chains an adjustment is provided to take up slack but where no such sueh provision Is made the chain must be bo shortened by taking out a link or else elsea a news new chain must be bo Installed If It chain noise becomes chronic the car owner owner will do well to consult commit a service station where an idler may be In Installed installed installed in- in stalled to take up slack One of the tho commonest of all nil knocks Is la that due to This m may maybe maybe y be caused by carbon too great an advance advance ad ad- vance vanco of the spark Bpark poor timing overheating overheating overheating over over- heating overload overloading InS InS' of the engine and incorrect mixture and the greatest of oC these is carbon In every case the charge explodes too soon not giving the piston time to reach the top of its journey and the result is that it is thrust against the side of the cylinder producing a knock The only way to cure this noise is to determine the cause by process of elimination and then do away with the cause Transmission noises are not at all I uncommon When one of the shafts is thrown out of alignment by reason of ot ofa ofa a worn or a binding binding- gear car noise I is bound to result Sometimes the transmission case Itself is out of true so that both shafts are thrown out of alignment Very often a gear will be broken because of or shaft misalignment and the owner has a new one Installed d. This however does not cure the cause of tho the breakage which la is misalignment misalignment ment and a second accident follows In Inthis Inthis this case the owner may assume that I the the shafts are out of or alignment an anthIs and I 1 this basic trouble must be corrected PROPELLER SHAFTS Propeller shafts and joints are no not t commonly troublesome in this way vay buthe but bu t the rear axle ade is frequently the seat o of f weird noises When the driving pinion n 1 and the differential master gear ar arnot are e not running true there will be a loud hum with a 3 sort of stress at each rev rev- Most cars have some form of ot adjustment to tal take e up wear in this lo location location lo- lo cation the adjustment consisting of shifting shirting the whole differential unit This is a o. Job for tor expert hands bands and should not be attempted by the owner unless he ho is a real mechanic This his constitutes the tho list of major noises but ut in addition there are numerous numerous nu nu- mercus minor squeaks squeals and rattles from springs body and chassis generally This springs and shackles if kept properly properly properly prop prop- erly lubricated will not emit noises I Body squeaks are hard to locate but butI by l keeping all nuts and bolts drawn I up tight most of them will be pre pre- vented Felt inserts will generally stop door squeaks Little strips of rubber wedged under the supports will cure fender Cender rattles and so it goes Hunting for noises and eliminating them Is more than a merely esthetic amusement Noise has no legitimate I place in the modern modem motorcar It isa Is Isa a sign of trouble or to come and the motorist who eliminates undue music as soon as It becomes audible is saving saving sav sav- ing himself trouble |
