Originator: Stephen I. Dains/sdains
Page 3
Date Issued: 2-16-04
guidebookcommon spring 2004.doc
DateRevised: 5/6/2004
D0303
It is expected that analyseswill beperformedondesignmodificationsmade to theFord chassis to
assure consistencywith theFord
BodyBuildersLayout BookorCD
,
IncompleteVehicle
Manual, applicableBulletins
, and this
GuideBook
. ApplicableFordServiceManual
procedures are tobe followedwhen chassis components are removed, altered, or reinstalled.
D0304
Analyses toFordguidelines should includeheat management, reliability, durability, fit, function,
customer expectation, andperformance.
D0305
Engineering specifications shouldbedeveloped to fully qualify fasteners for grade strength,
bearingarea, surface finish, andproper torque for all critical items. Other fastening systems, such
asweldingand riveting, shouldalsohavewritten specifications developed. Supplier expertise
shouldbe considered.
D0306
Aweight analysismust be conducted for each vehiclemodel offered in the currentmodel year to
demonstrate compliancewith theOEM chassismanufacturer's requirements:
•
Engineeringmust usea "four-corner" weight analysis process toaddress side-to-side loading
in thedesign. A "four corner" weight analysis is presented inAppendix II. AMicrosoft Excel
spreadsheet program is available toassist in theanalysis. Obtaina copy from theFordBody
BuildersAdvisoryService (1-877-840-4338)
•
Front and rear axleGrossAxleWeight Ratings (GAWRs)must not beexceeded.
•
Inorder toavoidoverloadingany tire, wheel or suspension component, GAWRs dividedby
twomust not beexceededat any of the four corners when the vehicle is fully loaded.
•
ChassisGrossVehicleWeight Ratings (GVWRs)must not beexceeded.
•
For vehicles less than10,000 lbs. GVWR, theapplicablemaximumUnloadedVehicleWeight
(UVW), as given in the IncompleteVehicleManual,must not beexceeded.
•
GrossCombinedWeight Ratings (GCWR)must beevaluatedandnot exceededon trailer
towingapplications.
D0307
Anelectrical loadanalysismust beperformedper industry specifications that consider all likely
vehicleduty cycleexperiences. The results of theanalysismust bedocumentedand remainon
file. SeeAppendix III
sectionof this guidebook for details.
D0308
Whereapplicable, testing shouldbeperformed to qualify designs for compliancewithgovernment
regulations.
D0309
Adocumented change control procedure should exist that ensuresmanagement sign-off for
Engineering, Production, Purchasing, QualityControl, andSales activities for bothoriginal
designs and in-process product designandassembly changes.
Changes occur often -- changes inproduct design, manufacturingmethods,materials, component
sources, etc.. If a regimented change control procedure is not employed, it is unlikely that
total
control
of overall operations is beingmaintained. Inorder toproduceandmaintainhighproduct
quality levels, a change control procedure that includes useof a change control form, shouldbe
adopted.
BeforePurchasing can change suppliers ormaterials, Engineering should sign-off. Production
shouldget Engineeringapproval for process changes. There shouldbea formal system toobtain
engineeringapproval beforedeviations to thedesignoccur; includingany revisions required for
productionor supplier issues. AppendixVII
includes a suggested "ChangeRequest" form, along
withdetailed instructions, to illustratehow todocument and control changes in thedesignand
manufacturingprocess.
