Bsi bs au 050 2 7a 1995 (1999)

Commit e s responsible Inside f ont cov erAnnex A informativ e Bus and truck ty re sidewal marking s 9 Annex C informativ e Ty pes of flang es, spring flang es and locking ring s 19 Fi

Tyres and wheels —

This British Stan ard,ha ing

b en pre ared u der the

direction of the Eng inering

Sector Bo rd, was publshed

u der the authority of the

Stan ards Bo rd an comes

into efect on

1 Decemb r 1 9

© BSI 0 -1 9

Fir t publshed Mar h 1 8

Secon edition Decemb r 1 9

The folowing BSI references

relate to the work on this

stan ard:

Commite reference AUE/4

Draft for comment 9 /70 9 2 DC

The prep ration of this British Stand rd was entrusted to Tech ical

Commit e AUE/4, Ty res and whe ls for motor v ehicles, upon which the

folowing bodies were represented:

Ag ricultural Eng ine r ’ Association

Automobie Association

British Industrial Truck Association

British Pres ure Gaug e Man facturer ’ Association

British Rub er Man facturer ’ Association

Confederation of Pas eng er Transport UK

Dep rtment of Transport

Freig ht Transport Association

Institute of Roa Transport Eng ine r ( Inc)

Motor Cy cle Industry ’s Association of Great Britain Ltd

Motor Industry Resear h Association

National Ty re Distributor ’ Association

Retrea Man facturer ’ Association

Roa Haulag e Association Ltd

Society of Motor Man facturer and Tra er Ltd

Am endm ents is ued sinc publ cation

Commit e s responsible Inside f ont cov er

Annex A ( informativ e) Bus and truck ty re sidewal marking s 9

Annex C ( informativ e) Ty pes of flang es, spring flang es and locking ring s 19

Fig ure B.7 — Earler and later ty pes of tubeles whe ls 17

Fig ure B.9 — Dual ( twin) whe l ofset or half dual sp cing 18

Fig ure C.1 — Cros -sections of ty pical flang es and locking ring s 20

This Section of BSA U5 has be n prep red b Technical Commit e AUE/4, and

g iv es g uid nce to v ehicle user on the selection of replacement ty res and whe ls

for commer ial v ehicles and on the care of ty res, whe ls and whe l fix ing s It is a

rev ision of BSAU5 -2.7:19 7, which is withdrawn

This rev ision up ates the recommend tions g iv en in the19 7 edition to take

ac ou t of dev elopments in desig n and practice, and prov ides more detaied

g uid nce in respect of care and maintenance

As a code of practice, this British Stand rd takes the form of g uid nce and

recommend tions It should not be quoted as if it were a specification and

p rticular care should be taken to ensure that claims of complance are not

— Se ton 2: Commer cia l vehicle tyr es;

— Se ton 3: Off-the-r oa d tyr es;

— Se ton 4: A gr icultur a l tr a cto a nd ma chine tyr es;

— Se ton 5: Ind ustr ia l vehicle tyr es;

— Se ton 6: Motor cycle tyr es;

— Se ton 7: Moped tyr es;

— Se ton 8: Cod e o pr a ctc fr the stor a ge o tyr es, in er tube a nd fla ps

— Pa r t 2: Whe ls a nd r ims;

— Se ton 0: Gener a l (includ ing ter ms a nd d efiniions, a nd constr ucton a nd

wor kma nship) ;

— Se ton 1: (Wihd r a wn

— Se ton 2: Spe ifica tion fr d imensions o whe l na ve a nd h b c ntr es fr

commer cia l vehicles;

— Se ton 3: Spe ifica tion f r r oa d -whe l n ts, stud s, a nd bol ts f r commer cia l

vehicles;

— Se t on 5: R oa d whe ls ma nufa ctur ed whol ly o pa r tly o ca st light a l loy f r

pa ss nger ca r s;

— Se ton 6: Spe ifica tion fr r oa d whe ls ma nufa ctur ed whol ly o pa r tl y o

l ight a l loy f r moped s a nd moto cycl es;

— Se ton 7: Cod e o pr a ct c f r the s l ecton a nd ca r e o whe ls f r commer cia l

vehicles;

— Se t on 8: Cod e o pr a ct c fr the s l ecton a nd ca r e o whe ls f r pa ss nger

ca r s (incl ud ing ca r a va ns a nd light tr a iler s)

— Se ton 5: Dimensions f r ISO cor e cha mber No 1 f r tyr e infla tion va lve ;

— Se ton 6: Dimensions f r ISO cor e cha mber No 2 f r tyr e infla tion va l ve ;

— Se ton 7: Cod e o pr a ctc fr the s lecton a nd ca r e o tyr e infl a tion va lve

f r pa ss nger ca r s (includ ing ca r a va ns a nd light tr a iler s) ;

— Se ton 8: Cod e o pr a ctc fr the s lecton a nd ca r e o tyr e infla tion va lve

f r commer cia l vehicl es

— Pa r t 4: R im pr ofiles a nd d imensions;

— Se ton 1: Ca r r ims;

— Se ton 2: Commer cia l vehicle r ims;

— Se ton 3: Off-the-r oa d r ims;

— Se ton 4: A gr icultur a l tr a cto a nd ma chine r ims;

— Se ton 5: Ind ustr ia l vehicle r ims;

— Se ton 6: Motor cycle r ims;

— Se ton 7: Moped r ims

A British Stand rd do s not purport to include al the neces ary prov isions of a

contract User of British Stand rds are responsible for their cor ect a pl cation

Com pl anc with a British Standard do s not of itselfc nfer im munity

f om leg al obl g ations

Summ ary of pag es

This document comprises a font cov er, an inside f ont cov er, p g es i to iv ,

p g es1to 20, an inside b ck cov er and a b ck cov er

This stand rd has be n up ated ( se copy rig ht d te) and ma hav e ha

amendments incorporated This wi be indicated in the amendment ta le on

theinside font cov er

7.1 Scope

This Section of BSAU5 -2 g iv es recommend tions

on the steps to be taken in selecting replacement

ty res and whe ls for commer ial v ehicles and on the

care of ty res, whe ls and whe l fixing s It des ribes

the princip l ty pes of whe ls and fixing s and the

procedures to be car ied out when fit ing whe ls

The ty pes of fixing s and siz s des ribed in this

stand rd are normaly used on heav y commer ial

v ehicles, but if used on other ty pes of v ehicle then

the principles upon which the recommend tions

g iv en in this stand rd are b sed also a ply

NOT 1 Recommen ations for the selection an care of whe ls

for p s eng r car an lght traier are giv n in BSAU5 -2.8

NOT 2 Attention is drawn to The Ro d V ehicles ( Construction

an Use) Re ulations1 8 [1] as amen ed

7.2 Ref rences

7.2.1 Normative referenc s

This Section of BSAU5 incorporates, b d ted or

und ted reference, prov isions f om other

publcations These normativ e references are ma e

at the a propriate places in the text and the cited

publcations are l sted on the inside b ck cov er For

d ted references, only the edition cited a pl es; any

subsequent amendments to or rev isions of the cited

publcation a ply to this Section of BSAU5 only

when incorporated in the reference b amendment

or rev ision For u d ted references, the latest

edition of the cited publcation a ples, tog ether

with any amendments

7.2.2 Inform ative referenc s

This Section of BSAU5 refer to other

publcations that prov ide information or g uid nce

Editions of these publ cations cur ent at the time of

is ue of this stand rd are lsted on the inside b ck

cov er, but reference should be ma e to the latest

editions

7.3 Tyre and wheel selection

The initial choice of ty re and whe l combination and

the ar ang ement at the p rticular whe l position is

ma e b the v ehicle man facturer in ac ord nce

with publshed per ormance and a plcation d ta

W here a v ehicle’s whe l and/or ty re specification is

chang ed after man facture e.g b bod buider ,

operator , or special st conv erter , this should be

done in consultation with the v ehicle man facturer

and hav ing reg ard to the folowing factor :

a) ty re/ whe l loa car y ing ca acity ( desig n and

leg al restrictions);

b) ma imum spe d of use;

c) dimensional constraints e.g ov eral v ehicle

heig ht, g round clearance, leg al ov eral v ehicle

width, ste ring lock ang le and suspension trav el;

d) comp tibi ty with existing a les, h bs, brake

as embles and suspension;

e) operation and serv ice conditions;

f) a plcation of whe l/ ty re as embly , e.g ste red

a le, driv e a le, f e rol ing a le, or twin whe l

N T Notes on tyre sidewal markings are giv n inAnne A

W he l ty es are des rib d in more detai inAnne B

7.4 Tyre selection

The ty re is the component which lnks the v ehicle

with the roa sur ace u der al conditions Its major

fu ctions which hav e a sig nificant influence on the

safety of the v ehicle can be summariz d as fol ows:

— loa car y ing ;

— cushioning ;

— transmis ion of driv e and braking for es;

— ste ring and handlng response

Primari y , the ty re should be ca a le of car y ing the

ma imum authoriz d loa on the a le to which it is

to be fit ed at the v ehicle’s leg al ma imum spe d

N T 1 Any tyre chosen as a re lacement should normaly b

of the same size, construction, an service des ription as the

original e uipment.The v ehicle an tyre man facturer ’ data

should b consulted when a tyre other than that sup led as

stan ard with the v ehicle is to b used or if the a plcation of the

v hicle is lkely to b chang d

A ty re is defined b the folowing :

a) siz desig nation comprising section width,

aspect ratio and rim diameter;

b) construction — normal y ra ial but les

fequently c os ply or bias belted;

c) ty pe of trea p t ern ac ording to indiv idual

man facturer’s desig nation;

d) serv ice des ription — loa index and spe d

sy mbol ( se BSAU5 -1.2.1 and/ or the ETRTO

Stand rds man al [2] for detais)

N T 2 Older tyres ma not ha e a sp ed symb l an ma

cary a ply rating inste d of a lo d in e

N T 3 If any f these factor is to b altered,the suita i ty of

the whe l for the amen ed tyre sp cification should also b

v rified an the factor lsted in7.3 a) to f) should b considered

7.5 Wheel selection

7.5.1 General

The factor afecting whe l selection are those lsted

in7.3 a) to f) Any whe l chosen as a replacement

should be suita le for the a plcation and normal y

of the same ty pe, siz , rim section, ofset and fixing

sy stem as the orig inal equipment Variations in the

pier ing or v enting p t erns in the whe l dis when

mixed on one v ehicle are permis ible prov ided that

ac es to the ty re v alv es on dual ( twin) whe ls is

maintained and brake co lng is not imp ired Any

v ariation in whe l specification fom the orig inal

should be v erified with the v ehicle manufacturer

and/or the factor l sted in7.3 a) to f) checked

W hen it is proposed to fit replacement whe ls where

the material ty pe ( e.g ste l, cast iron, aluminium

al oy ), nav e thick es or nav e contour v aries f om

the orig inal, special consideration should be g iv en to

the suita i ty of the fixing sy stem

In p rticular, the folowing points should be

checked:

a) comp tibi ty of the fixing s se 7.6;

b) stud leng th ( where nav e thick es has

chang ed);

c) clearance arou d brake, h b, and ste ring

components;

d) fitment and al g nment of ty re v alv es on sing le

and dual whe l ar ang ements; and

e) half dual sp cing or ofset for the ty re siz to

g iv e proper clearance when whe ls are twin ed

or to maintain normal ste ring characteristic on

ste r a les

NOT For detaied des riptions of of ets se B.2

7.5.2 Whe l and rim desig ns

Annex B lsts the ty pes of rims and whe ls in

g eneral use and these are i ustrated inFig ure B.1

toFig ure B.9

Annex C g iv es des riptions of the ty pes of flang es

and locking ring s for use with the rims and whe ls

which are l sted inAnnex B, and c os -sections of

ty pical flang es and locking ring s are i lustrated

inFig ure C.1 The endles flang es, spring flang es

and locking ring s for flat b se, semi drop centre

( SDC) and wide b se rims i ustrated inFig ure C.1

are not inter hang ea le The cor ect siz and ty pe

should alway s be used as serious ac idents can

result f om the wrong a plcation

It is es ential that endles flang es, spring flang es,

locking ring s and rims fom diferent man facturer

are not intermixed

W hen the ty re is fit ed for inflation with the spring

flang e ( two piece rim) or locking ring ( thre /four

piece rim) in its cor ect position in the rim g ut er, it

is es ential that the ends of the ring are not

touching as this prev ents cor ect seating

W ARNING 1 It is emphasiz d that only the rim

profies are desig nated in BSAU5 -4.2.1 and the

withdrawn BSAU5 -2.1 W hi e the rim profies

and dimensions ma a pear suita le the whe l

strength ma not be and should be determined

before use

W ARNING 2 The use of replacement “ dual

purpose” whe ls ( se 7.6) is not recommended

7.5.3 Fit ing of sing le whe ls in plac of twin

whe ls and the use of spac r

W here sing le whe ls are fit ed as replacements for

twin whe ls, a ditional at ention should be g iv en to

the whe l fixing s.I the orig inal studs or bolts hav e

plain shan s which are to long for the n ts to

tig hten on to the whe l or if the projecting leng th of

the studs or bolts would a v er ely afect the fit ing

of socket sp nner , it is recommended that suita le

replacement studs or bolts are fit ed

( se p rag ra h2 of7.7.4)

I sp cer are used to compensate for the a sence of

the in er whe l, such sp cer should be of g ra es of

ste l or cast iron of a hardnes not les than HV15

They should be ac urately machined with an outside

diameter not exce ding that of the whe l mou ting

face on the h b or brake drum and be f e f om

sharp edg es.( Se also BSAU5 -2.2.) The combined

thick es of the sp cer and the sing le whe l should

be equal to the thick es of the original twin whe l

as embly

7.6 Wheel fixing s

The majority of modern heav y commer ial v ehicles

use spig ot located whe ls, where the whe l is

central z d b the close fit of the whe l centre bore

on the h b spig ot W ith this ty pe of mounting the

whe l has plain stud holes and flat faced nuts with

ca tiv e washer to clamp the whe l to the h b face

Older United King dom v ehicles ( and some modern

l g ht commer ial v ehicles) hav e conical stud hole

seating s that mate with the matching ta er of the

whe l n ts both to centralz and sup ort the whe l

on the v ehicle On dual ( twin) whe ls the in er

whe l is centralz d b and sup orted on a ta ered

col ar or ta ered splt washer on the whe l stud

shan

Older ty pes of European commer ial v ehicles hav e a

simi ar ty pe of whe l mounting but the seating is

spherical which is fu d mentaly diferent f om the

UK conical seating It is es ential that these UK

( BSconical seating ) and European ( DIN spherical

seating ) whe ls are not in any cir umstances

inter hang ed ev en thoug h it is phy sical y pos ible

and they a pear to be comp tible The conical and

spherical components do not mate tog ether and if

combined, lo se whe ls result

It is v ital to check that the whe l nuts and seating s

are comp tible to av oid incor ect matching Fig ure 1

shows ty pical whe l fixing s for conical seating ,

spherical seating and spig ot mou ting

Se BSAU5 -2.2 for dimensional detais

W he ls specificaly designed for conical or spherical

seating should nev er be used on h bs desig ned for

spig ot fix ing

Some replacement whe ls hav e be n produced

which are desig ned to be used in a “ dual purpose”

mode The h b bore is dimensioned to suit spig ot

fixing but the stud holes are profied to suit either

DIN spherical or BS conical fixing n ts The use of

these whe ls is not recommended

7.7 Care and m aintenance ofwheels

and tyr s

7.7.1 General

The care and maintenance of whe ls, whe l fixing s

and ty res fal s into thre areas as folows:

a) routine and special checks car ied out b the

driv er( s) or other desig nated per ons ( se 7.7.2);

b) periodic inspections b v ehicle maintenance

staf as p rt of the v ehicle maintenance s hedule

( se 7.7.3);

c) inspections b maintenance staf or specialst

ty re fit er when ty res are chang ed or when

whe ls are remov ed for any other reason

( se 7.7.4)

I there are sig ns that a ty re has substantial y

deflated or has sto d in a deflated condition, the ty re

and/or whe l components ma hav e become

d mag ed or displaced The as embly should be

remov ed fom the v ehicle and the ty re remov ed f om

the whe l The ty re should be ex mined to

determine the reason for deflation and whether it is

suita le for further serv ice Each component p rt of

the whe l should also be ex mined and replaced as

neces ary before being reas embled

Any whe l fou d lo se at inspection should be

remov ed and the fixing s, whe l and h b checked for

wear and d mag e

The whe l fit ing procedure g iv en in7.8 should be

folowed when remounting

7.7.2 Routine in- servic che ks

During normal v ehicle use ty res and whe ls should

be v isualy ex mined reg ularly ( prefera ly at the

start of each shift)

Ty res should be ex mined for d mag e, a normal or

exces iv e wear, u der- nflation and foreig n objects

embed ed in them or tra ped betwe n dual ( twin)

ty res

W he ls should be checked for sig ns of d mag e,

c acks, distorted rims, displaced spring flang es or

locking ring s, broken or lo se fit ing s and sig ns of

whe l lo senes e.g brig ht metal or rust marks in

the area of n ts or ca tiv e washer seating s

I lo senes is suspected, the whe l n ts should be

checked phy sical y using the whe l n t wrench

sup led with the v ehicle b the v ehicle

man facturer, or a socket and short b r of

cor esponding leng th

Any defects, including lo se whe l nuts, should be

reported immediately and the v ehicle should not be

driv en further without clear authority I whe l

fixing s are lo se, there is a reason The whe l should

be remov ed and al relev ant components ex mined

as so n as practica le

W ARNING Retig htening lo se whe l n ts on the

roa ( or any where else) without fir t as ertaining

the reason for lo senes and the extent of any wear

or d mag e is potential y d ng erous Ov ertig htening

of whe l fixing s ( e.g b using extension b r ) can

result in d mag e to fixing s, whe ls and hubs, the

subsequent fai ure of which can result in whe l los

7.7.3 Periodic m aintenanc inspe tions

These inspections should be car ied out reg ularly in

ac ord nce with the prev entativ e maintenance

s hedule is ued b the v ehicle man facturer which

should incorporate the items l sted in7.7.2 but in

g reater depth, e.g ty re pres ure should be checked

and a justed as neces ary to the cor ect v alue

7.7.4 Inspe tions when whe ls are rem oved

NOT 1 For the remo al an refiting of whe ls an tyres,

se 7.7.5,7.7.6 an 7.8

On remov al of the whe ls the folowing should be

inspected

All d mag ed or worn components should be renewed

and the dis arded p rts s ra ped It is

recommended that replacement studs and n ts

should conform to BSA U5 -2.3

W ARNING W elding is not recommended as an

ac epta le form of rep ir The a plcation of heat to

a whe l and ty re ma cause an ex losion even when

the ty re is deflated

a) Studs:

1) Threa s should be ex mined to ensure that

they are fe fom debris and obv ious d mag e

NOT 2 The n t should ru fe ly o er the whole leng th

of the thre d b han action only

2) Retention should be checked, if the brake

drum has be n remov ed; the b ck ut or stud

hea should be ex mined for sig ns of

mov ement and cor ect seating ag ainst the h b

face

3) I the in er cone seating on BS conical fixed

mou ting s is machined on to the stud itself, it

should be ex mined for sig ns of wear or po r

mating with the whe l seat

4) The stud should be ex mined for distortion

and c acks or waisting , p rticularly at the

threa runout or at section chang es

b) Nuts:

1) Threa s should be ex mined to ensure that

they are fe fom debris and obv ious d mag e

NOT 3 The n t should ru fe ly on the stu b han

action only

2) Flats should be ex mined for d mag e

3) In the case of conical or spherical seating s,

the condition of mating faces should be

ex mined including ex mination for distortion

or u ev en seating

4) In the case of spig ot mou ted fixing s, the

ca tiv e washer should be ex mined for

f e dom and a sence of u due rotational

f iction when pres ed ag ainst the n t

5) W hen replacing n ts, only components to

the orig inal material specification should be

used They should be ex mined for

concentricity and g eneral finish qualty

c) Hubs and drums:

1) All faces that mate with the flat whe l nav e

surace should be ex mined to ensure that they

are clean, flat, f e f om surace protrusions,

and cor osion and prefera ly f e of p int

Howev er, if p inted, one thin coat of p int not

ex ce ding25Èm ( 1 thou) is the ma imum

alowa le I in doubt any p int should be

remov ed or the thick es measured using

a propriate measuring equipment

2) On spig ot mou ted fixing s the h b spig ot

seating , whether contin ous or sectored,

should be ex mined to ensure that the seating s

are f e f om dirt, debris, edg e or sur ace bur s

and ev idence of f et ing or whe l to h b

mov ement

d) Lo se conical or spherical faced washer :

1) These should be ex mined to ensure that

they are of the same siz and ty pe

N T 4 BS conical an DIN spherical fixings should not

b mix d;neither should splt an sold washer

2) W here lo se washer are used as the inner

seating on the whe l mou ting , they should

not be remov ed unles neces ary They should

be checked to ensure that al are present and in

g ood condition

e) W he ls:

1) The mou ting faces of whe ls where they

contact the hub, the brake drum or the

washer or flat-faced n ts should be ex mined

to ensure that they are clean, flat, and f e

fom sur ace protrusions, cor osion and de p

s ores I p inted the surace should be lmited

to one thin coat not exce ding25Èm( 1thou)

[ se item c)1)]

2) Those p rts ofthe face which contact conical

n t-faces or spherical n t-faces should be

ex amined to ensure that they are clean and

fe f om de p s ores, protrusions, and p int

f) Ty res:

1) The ty re should be checked to ensure that it

is the cor ect siz and ty pe for the p rticular

a le position and that it is of the cor ect serv ice

des ription

2) The ov eral condition of the ty re should be

checked It should be ex mined for sig ns of

d mag e such as cuts, bulg es or a rasions.The

remaining trea depth should be measured,

and any objects tra ped or embed ed in the

ty re should be remov ed

3) The v alv e should be checked to ensure that

it is in g ood condition and that a hig h pres ure

seal ng v alv e ca is fit ed

7.7.5 Rem ov l of whe ls

No per on should be inv olv ed in the remov al of

whe ls fom v ehicles, p rticularly heav y

commer ial v ehicles, u les they hav e receiv ed

instruction and are aware ofthe g uid nce g iv en in

the Health and Safety Executiv e bo klet, Hea lth

a nd sa fety in tyr e a nd exha ust fitng pr emis s[ 3]

In g eneral when remov ing a whe l f om a v ehicle

the folowing procedure should be a pl ed

a) Ensure that the work can be car ied out safely,

that the p rk brake is a pled and that whe l

chocks are in place Slacken of the whe l fix ing s

before jacking the v ehicle

b) Ensure that a suita le jack is used at the

recommended jacking points and that the jack is

on sta le g rou d or sprea plates are used

c) I the whe l is c acked or d mag ed deflate the

ty re before at empting to remov e the whe l In

the ev ent of dificulty in the remov al of a whe l

f om a h b or drum, u der no cir umstances

should direct hammer blows be ma e to the whe l

rim A suita le to l desig ned for the remov al of

whe ls should be used Howev er, in the a sence

of such a to l a protectiv e block of wo d or a soft

faced malet should be used with caution

d) Before remov ing div ided whe ls fom the

v ehicle, deflate the ty res b remov ing the v alv e

core to av oid v iolent sep ration in the ev ent of

clamping bolt faiure

W ARNING Under no cir umstances should

outer clamping nuts of div ided whe ls be

lo sened or u s rewed before deflation ofthe

ty re This warning a ples ev en if the outer

clamping n ts are colour coded in ac ord nce

with0.3.10.2 of BSAU5 -2.0, as fol ows:

— red for whe ls p inted in colour other than

red;

— y elow for whe ls p inted red

7.7.6 Rem oving and fit ing tyres

The remov al and fit ing of ty res should be car ied

out b competent per onnel p y ing due reg ard to

the ty re and v ehicle man facturer ’ instructions

and the g uid nce g iv en in the Health and Safety

Executiv e bo klet, Hea lth a nd sa fety in tyr e a nd

exha ust fit ng pr emis s [ 3]

In g eneral terms the fol owing procedure should be

fol owed

NOT An a pro ed tyre b ad lubricant should alway s b used

when fiting or remo ing tyres

a) Ensure that al to ls are suita le, in g ood

condition and cal brated where a propriate

b) Before demou ting any ty re f om a whe l

remov e the v alv e core and make sure the ty re is

deflated

Care should be taken to av oid injury fom the air

blast

c) Take care not to distort any spring flang es and

locking ring s when dismantl ng the ty re/whe l

I they are d mag ed, distorted, c acked, broken

or exces iv ely cor oded it is es ential that they

are not reused

f) Clean al sur aces, p y ing p rticular at ention

to the bea seat and those sur aces which mate

ag ainst the h b or twin ed as embly

g ) Renew the v alv e seals, v alv e core, or the

complete v alv e if d mag ed

h) Thoroug hly ex mine the ty re inside and

outside for d mag e

i Ensure the cor ect siz and ty pe of ty re, tube,

fla , flang es and locking ring s are used

j) Once a whe l and ty re hav e be n as embled

and before any inflation, check the positioning of

any spring flang es and locking ring s

The ends of lo se flang es and locking ring s

should be ofset

k) Before any inflation esta l sh the cor ect ty re

inflation pres ure for the ty re a pl cation

l Inflate the ty re to a pres ure of not more

than10 kPa

1)

( 15psi and then check that the

ty re is properly centred on the rim and that the

flang es and locking ring s are cor ectly seated

m) Before inflating any ty re

a ov e10 kPa

1)

( 15psi ensure that the

folowing safety precautions are taken

1) Put the demou ted ty re/whe l as embly into

a safety cag e or a porta le safety dev ice

2) In exceptional cir umstances where safety

dev ices are not av ai a le position any

as embly with a spring flang e or lo se flang e

and locking ring so that these are facing a

protectiv e b rr ier such as the side of a v ehicle,

a wal or an emb n ment

3) At al times when inflating a ty re mou ted

on a v ehicle h b, stand wel clear of the area in

f ont of the as embly

1)

1 0 kPa = 1 b r

n) Check the pres ure periodical y during

inflation I any u ex laina le bulg es a pear

during inflation deflate the ty re and inv estig ate

the cause

Nev er inflate a ov e the ma imum pres ure

alowa le for the siz and loa ca acity of the

ty re as specified b the ty re man facturer

W ARNING Air lnes should be fit ed with at

least3m of hose betwe n the cl p-on ch ck and the

airl ne control, and it is es ential that an

u at ended airlne control is nev er left at ached to a

v alv e During inflation, al per on el should be kept

wel clear of the as embly

7.8 Wheel fit ing and nut tig htening

procedure

Before refit ing a whe l it should be ensured that

the inspections l sted in7.7.4 hav e be n completed

It is es ential when mou ting whe ls on a v ehicle

that they are al centred cor ectly to av oid ov er

strained or factured studs, distortion of the whe ls,

hub flang es and brake drums, lo sening of the

whe ls, and elong ated stud holes

Lubrication of fixing s has a g reat influence on the

tig htnes of a fixing for a g iv en torque and as a

g eneral rule al whe l fixing threa s should be

lubricated with oi before as embly Also p rticular

at ention should be g iv en to the lubrication of the

nut/ca tiv e washer inter ace of spig ot mou ted

fixing s This ensures the elmination of u due

f iction betwe n the n t and its ca tiv e washer

W hen mou ting whe ls that hav e spherical or

conical seating s the v ehicle man facturer’s

recommend tions reg arding lubrication should be

folowed

Before fit ing the whe l it is important to ensure

that the hub or drum and nav e faces are clean, the

drum is cor ectly seated and, in the case of spig ot

located whe ls, the spig ot and whe l bore are clean

The vehicle should be jacked up so that the ty re

clear the g rou d, then the whe l or twin whe ls

pushed home on the studs and al the n ts s rewed

on fing er tig ht ( It should be checked that the

inflation v alv e is cor ectly al g ned and ac es ible

when fit ing twin whe ls.) One n t should nev er be

tig htened completely whi e the other are sti l lo se

The final tig htening should be g ra ual and

prog res iv e b g iv ing one p rtial turn at a time to

each nut in the sequence shown inFig ure 2 a),

Fig ure 2 b) or Fig ure 2 c), as a plca le

The final tig htening of the n ts should be done with

a cal brated torque wrench set to the v ehicle

man facturer’s recommended torque v alue An air

imp ct to l should nev er be used for the final

tig htening , and neither should extensions on whe l

n t sp n er and spider as ov er-tig htening ma

result in stretched threa s, broken studs and

c acked or distorted whe ls

Fol owing a whe l fit ing , the n ts should be

rechecked for tig htnes after the v ehicle has sto d

for3 min or trav el ed for a distance betwe n4 km

and8 km ( 25mi es to5 mies), using a torque

wrench and recommended torque v alues Checking

should not be done b slackening and retig htening

the n ts, but just b a plcation of the tig htening

torque

Routine in-serv ice checks should take place

thereafter and the fixing s rechecked for tig htnes in

ac ord nce with the v ehicle’s prev entativ e

maintenance s hedule

Fig ure 2 — Sequenc ofstud tig htening