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© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois.

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Presentation on theme: "© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois."— Presentation transcript:

1 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois by Russell Krick

2 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only

3 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Fasteners  Washers  Machine screws  Sheet metal screws  Nonthreaded fasteners (9 Topics)

4 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Torquing bolts and nuts  Thread repairs  Removing damaged fasteners  Gaskets and seals

5 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Devices that hold the parts of a vehicle together  Thousands of fasteners are used in vehicles

6 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Automotive Fasteners

7 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Bolt  metal rod with external threads on one end and a head on the other  when a bolt is threaded into a part other than a nut, it can also be called a cap screw  Nut  has internal threads and, usually, a six- sided outer shape Bolts and Nuts

8 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolts and Nuts When a nut is screwed onto a bolt, a powerful clamping force is produced

9 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Dimensions

10 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Dimensions

11 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Thread Types  There are three basic types of threads used on fasteners:  Coarse threads  UNC-Unified National Coarse  Fine threads  UNF-Unified National Fine  Metric threads  SI

12 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Thread Direction  Bolts and nuts come in right- and left- hand threads  Right-hand threads  fastener must be turned clockwise to tighten  Left-hand threads  fastener must be turned counterclockwise to tighten  letter L may be stamped on fastener

13 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Grade  Also called tensile strength  Refers to the amount of pull a fastener can withstand before breaking  Bolt head markings specify the tensile strength of the bolt  U.S. customary bolts are marked with lines  Metric bolts are marked with numbers

14 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Description Gives information about the bolt

15 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Description Used when purchasing new bolts

16 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Description

17 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Nut Types Common types of nuts used in vehicles

18 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Castle Nut and Cotter Pin Cotter pin keeps the nut from turning and possibly coming off

19 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Used under bolt heads and nuts  Two basic types of washers are used:  flat washers  lock washers

20 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Washer Types  Flat washer  increases the clamping surface under the fastener  prevents the bolt or nut from digging into the part  Lock washer  prevents the bolt or nut from becoming loose under stress and vibration

21 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Washer Types  Lock tabs or lock plates  perform the functions of both flat washers and lock washers  increase clamping surface area and secure the fastener

22 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Washer Types A. Plain flat washerB. Split lock washer C. Toothed lock washerD. Lock plate

23 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Similar to bolts, but they normally have screw-type heads  Threaded along their full length  Used to secure parts when clamping loads are light  Available in various head shapes

24 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Also called tapping screws  Commonly used on plastic and sheet metal parts, such as body trim, dashboard panels, and grills  Use tapering threads that are widely spaced

25 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Sheet Metal Screws

26 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Numerous types of nonthreaded fasteners, such as snap rings, clips, and adhesives, are used in the assembly of a vehicle

27 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Snap Ring  Fits into a groove in a part and commonly holds shafts, bearings, gears, pins, and other components in place  Snap ring pliers are needed to remove and install a snap ring  special jaws grasp the snap ring

28 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Snap Ring Types

29 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Keys and Set Screws  Key  prevents a part from turning on its shaft  fits into a keyseat (slot) cut into a shaft and a keyway cut into the mating part  Set screw  normally used to lock a part onto a shaft  not as strong as a key

30 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only A. Key B. Set screw Keys and Set Screws

31 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Splines  Series of slots cut into a shaft and a mating part  Allow the gear or collar to slide on the shaft but still not rotate  Used in manual transmissions, clutches, and drive shaft yokes

32 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Splines

33 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Adhesives  Special glues widely used in vehicles  Used to hold body moldings, rubber weather stripping, and body emblems  Some stay soft and pliable; others dry hard  Some take hours to dry; others dry in seconds  Observe all directions and safety precautions when using adhesives

34 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only It is very important that bolts and nuts be tightened properly—this is called torquing

35 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Torque Specifications  Tightening values given by the auto manufacturer  Normally given for all precision assemblies, such as engines, transmissions, and differentials  Factory specifications should be used  general bolt torque chart may be used if factory specs are not available

36 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Torque Chart

37 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Torque-to-Yield  Requires a bolt to be tightened to a specific torque and then turned an additional number of degrees  Procedure stretches the bolt to its correct yield point, preloading the fastener for better clamping under varying conditions  New bolts may be required each time

38 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Torque Stretch  Determined by measuring bolt length change while torquing the bolt  when building a racing engine, you can “mike” connecting rod bolts to measure the length before and after tightening  Too much stretch indicates bolt weakness  Not enough stretch may indicate thread problems affecting torque

39 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Tightening Sequence  Used to make sure that parts are fastened evenly  Creates an even, gradual clamping force along the entire mating surface of the parts  Crisscross pattern is often recommended

40 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Tightening Sequence Service manual pattern for a cylinder head

41 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bolt Tightening Sequence Service manual pattern for wheel lug nuts

42 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Torque Wrench Rules  Keep a steady pull on the wrench  Clean fastener threads  Avoid using swivel joints  When reading a torque wrench, look straight down at the scale  Use manufacturer’s specifications when available

43 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Torque Wrench Rules  When manufacturer’s specs are not available, use general specs in a crisscross pattern  To avoid a false reading, pull only on the handle  Tighten bolts and nuts in four steps  Retorque when required  some assemblies must be retightened after operation and heating

44 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Threaded holes in parts can become damaged, requiring repairs. A technician must be capable of repairing damaged threads quickly and properly.

45 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Minor Thread Repairs  Minor thread damage includes nicks, partial flattening, and other less serious problems  Minor damage can be repaired with a thread chaser or a thread file  the thread chaser is run through or over the threads to restore them

46 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Major Thread Repairs  Badly smashed or stripped threads may be repaired with either a tap or die  Tap  threaded tool for cutting internal threads in holes  Die  cuts external threads on metal rods, bolts, shafts, and pins

47 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tap and Die

48 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Using a Tap and Die  Hold the handle squarely with the work  Back the handle off to clean metal out of the threads  Use a taper tap to start the threads  Use a plug tap and a bottoming tap to cut the threads to the bottom of the hole

49 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tap and Die Rules  Never force a tap handle or the tool may break  Keep the tap and die well oiled to ease cutting  Use coarse threads when threading or tapping into soft metal, like aluminum  coarse threads will hold better than fine threads

50 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tapping Oversize  When threads cannot be restored, the hole can be drilled and tapped oversize  Use a “drill and tap size chart” to choose a drill bit and tap  Drill the hole one size larger than the original hole  Cut new threads in the drilled hole  Use a larger bolt in the threaded hole

51 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Thread Repair Insert  Used when the use of an oversize hole and fastener is not acceptable  Takes place of damaged internal threads  Allows the use of the original-size bolt

52 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Using an Insert A. Drill the hole oversize B. Tap the hole oversize C. Mount the insert on a mandrel D. Thread the insert into the hole

53 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Insert allows the use of the original-size bolt Using an Insert

54 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Damaged threads before a repair Installed insert Using an Insert

55 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  An automotive technician must be able to remove broken bolts, screws, and studs, as well as fasteners having rusted or rounded-off heads  Specific tools and methods are needed for removing problem fasteners

56 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Removal Methods  Grasp a rusted or rounded head with locking pliers  Use a stud puller or stud wrench  removes studs and bolts broken off above the surface of the part

57 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Removal Methods  Cut a slot in the fastener with a hacksaw or weld on a nut to grasp  Use a hammer and punch  angle the punch so that blows from the hammer can drive out the broken fastener  Drill a hole almost as large as the inside diameter of the threads  use a tap or punch to remove the thread shell

58 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Removal Methods Using a screw extractor A. Drill a hole B. Tap the extractor into the hole C. Unscrew the extractor and bolt

59 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Removal Methods Use rust penetrant to help ease turning and prevent fastener breakage

60 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Used between parts to prevent leakage of engine oil, coolant, transmission fluid, and other fluids

61 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Gaskets  Soft, flexible material placed between parts to prevent leakage  Made of fiber materials, rubber, neoprene (synthetic rubber), cork, treated paper, or thin steel  When parts are fastened together, the gasket material fills small gaps, dents, or scratches in the mating surfaces

62 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Gasket Rules  Inspect for leaks before disassembly  Be careful not to damage mating surfaces while removing parts  Clean off old gaskets carefully  Wash and dry parts thoroughly  Compare the new gasket to the shape of the mating surface

63 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Gasket Rules  Use a sealer if specified  When assembling, start all bolts by hand  Tighten fasteners in steps  Use a crisscross tightening pattern  Do not overtighten fasteners  apply only the specified torque

64 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Sealers Gaskets are often coated with a sealer to help prevent leakage and to hold the gasket in place during assembly

65 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Types of Sealers

66 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Form-in-Place Gaskets  Used instead of conventional fiber or rubber gaskets  Two common types are:  room temperature vulcanizing (RTV) sealer  anaerobic sealer

67 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only RTV Sealer  Also called silicone sealer  Dries in contact with air  Used to form a rubber-like gasket on thin, flexible flanges  Available in tubes  has a shelf life of one to two years

68 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only RTV Sealer Commonly recommended where two different gaskets join

69 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Using RTV Sealer  Apply in a continuous bead that is approximately 1/8” (3 mm) wide  Circle all mounting holes  Torque components in place while the RTV is still wet to the touch  within about 10 minutes of application

70 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Anaerobic Sealer  Cures to a plastic-like substance in the absence of air  Designed for tightly fitting, thick parts  Used between two smooth, true surfaces

71 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Using Anaerobic Sealer  Apply in a continuous bead that is approximately 1/16"–3/32" (1.5 mm– 2 mm) wide  Circle all mounting holes  Torque components in place within 15 minutes of sealer application

72 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Using Sealers Both anaerobic and RTV sealers are used on this water pump

73 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Seals  Prevent leakage between a stationary part and a moving part  Found in engines, transmissions, power steering units, and any part containing fluid and moving parts  Made of synthetic rubber molded onto a metal body

74 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Seal Application Seal lip faces the fluid and keeps it inside the part

75 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Seal Rules  Inspect the seal for leakage before disassembly  if the seal is leaking, look for a bent shaft, misaligned seal housing, or damaged parts  Remove the old seal carefully, without scratching the seal housing

76 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Seal Rules Inspect shafts for wear and burrs

77 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Seal Rules  Compare the old seal to the new seal  make sure the inner and outer diameters match before installation  Install the new seal correctly  coat the outside with an approved sealer  coat the inner lip of the seal with system fluid  install the seal with the sealing lip toward the inside of the part

78 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only O-Ring Seal  Stationary seal that fits into a groove between two parts  When the parts are assembled, the synthetic rubber seal is partially compressed to form a leakproof joint

79 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Normally, the O-ring seal is coated with system fluid before installation O-Ring Seal

80 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Synthetic Seal Specially-shaped seal that fits down into a groove formed in the part


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